Python2/PyMuPDF: mupdf-source/thirdparty/leptonica/src/pixconv.c comparison

comparison mupdf-source/thirdparty/leptonica/src/pixconv.c @ 2:b50eed0cc0ef upstream

ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.

author	Franz Glasner <fzglas.hg@dom66.de>
date	Mon, 15 Sep 2025 11:43:07 +0200
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-:1d09e1dec1d9
+:b50eed0cc0ef
+/*====================================================================*
+-  Copyright (C) 2001 Leptonica.  All rights reserved.
+-
+-  Redistribution and use in source and binary forms, with or without
+-  modification, are permitted provided that the following conditions
+-  are met:
+-  1. Redistributions of source code must retain the above copyright
+-     notice, this list of conditions and the following disclaimer.
+-  2. Redistributions in binary form must reproduce the above
+-     copyright notice, this list of conditions and the following
+-     disclaimer in the documentation and/or other materials
+-     provided with the distribution.
+-
+-  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+-  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+-  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+-  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ANY
+-  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+-  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+-  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+-  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+-  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+-  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+-  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*====================================================================*/
+/*!
+* \file pixconv.c
+* <pre>
+*
+*      These functions convert between images of different types
+*      without scaling.
+*
+*      Conversion from 8 bpp grayscale to 1, 2, 4 and 8 bpp
+*           PIX        *pixThreshold8()
+*
+*      Conversion from colormap to full color or grayscale
+*           PIX        *pixRemoveColormapGeneral()
+*           PIX        *pixRemoveColormap()
+*
+*      Add colormap losslessly (8 to 8)
+*           l_int32     pixAddGrayColormap8()
+*           PIX        *pixAddMinimalGrayColormap8()
+*
+*      Conversion from RGB color to 8 bit gray
+*           PIX        *pixConvertRGBToLuminance()
+*           PIX        *pixConvertRGBToGrayGeneral()
+*           PIX        *pixConvertRGBToGray()
+*           PIX        *pixConvertRGBToGrayFast()
+*           PIX        *pixConvertRGBToGrayMinMax()
+*           PIX        *pixConvertRGBToGraySatBoost()
+*           PIX        *pixConvertRGBToGrayArb()
+*           PIX        *pixConvertRGBToBinaryArb()
+*
+*      Conversion from grayscale to colormap
+*           PIX        *pixConvertGrayToColormap()  -- 2, 4, 8 bpp
+*           PIX        *pixConvertGrayToColormap8()  -- 8 bpp only
+*
+*      Colorizing conversion from grayscale to color
+*           PIX        *pixColorizeGray()  -- 8 bpp or cmapped
+*
+*      Conversion from RGB color to colormap
+*           PIX        *pixConvertRGBToColormap()
+*
+*      Conversion from colormap to 1 bpp
+*           PIX        *pixConvertCmapTo1()
+*
+*      Quantization for relatively small number of colors in source
+*           l_int32     pixQuantizeIfFewColors()
+*
+*      Conversion from 16 bpp to 8 bpp
+*           PIX        *pixConvert16To8()
+*
+*      Conversion from grayscale to false color
+*           PIX        *pixConvertGrayToFalseColor()
+*
+*      Unpacking conversion from 1 bpp to 2, 4, 8, 16 and 32 bpp
+*           PIX        *pixUnpackBinary()
+*           PIX        *pixConvert1To16()
+*           PIX        *pixConvert1To32()
+*
+*      Unpacking conversion from 1 bpp to 2 bpp
+*           PIX        *pixConvert1To2Cmap()
+*           PIX        *pixConvert1To2()
+*
+*      Unpacking conversion from 1 bpp to 4 bpp
+*           PIX        *pixConvert1To4Cmap()
+*           PIX        *pixConvert1To4()
+*
+*      Unpacking conversion from 1, 2 and 4 bpp to 8 bpp
+*           PIX        *pixConvert1To8()
+*           PIX        *pixConvert2To8()
+*           PIX        *pixConvert4To8()
+*
+*      Unpacking conversion from 8 bpp to 16 bpp
+*           PIX        *pixConvert8To16()
+*
+*      Top-level conversion to 1 bpp
+*           PIX        *pixConvertTo1Adaptive()
+*           PIX        *pixConvertTo1()
+*           PIX        *pixConvertTo1BySampling()
+*
+*      Top-level conversion to 2 bpp
+*           PIX        *pixConvertTo2()
+*           PIX        *pixConvert8To2()
+*
+*      Top-level conversion to 4 bpp
+*           PIX        *pixConvertTo4()
+*           PIX        *pixConvert8To4()
+*
+*      Top-level conversion to 8 bpp
+*           PIX        *pixConvertTo8()
+*           PIX        *pixConvertTo8BySampling()
+*           PIX        *pixConvertTo8Colormap()
+*
+*      Top-level conversion to 16 bpp
+*           PIX        *pixConvertTo16()
+*
+*      Top-level conversion to 32 bpp (RGB)
+*           PIX        *pixConvertTo32()   ***
+*           PIX        *pixConvertTo32BySampling()   ***
+*           PIX        *pixConvert8To32()  ***
+*
+*      Top-level conversion to 8 or 32 bpp, without colormap
+*           PIX        *pixConvertTo8Or32
+*
+*      Conversion between 24 bpp and 32 bpp rgb
+*           PIX        *pixConvert24To32()
+*           PIX        *pixConvert32To24()
+*
+*      Conversion between 32 bpp (1 spp) and 16 or 8 bpp
+*           PIX        *pixConvert32To16()
+*           PIX        *pixConvert32To8()
+*
+*      Removal of alpha component by blending with white background
+*           PIX        *pixRemoveAlpha()
+*
+*      Addition of alpha component to 1 bpp
+*           PIX        *pixAddAlphaTo1bpp()
+*
+*      Lossless depth conversion (unpacking)
+*           PIX        *pixConvertLossless()
+*
+*      Conversion for printing in PostScript
+*           PIX        *pixConvertForPSWrap()
+*
+*      Scaling conversion to subpixel RGB
+*           PIX        *pixConvertToSubpixelRGB()
+*           PIX        *pixConvertGrayToSubpixelRGB()
+*           PIX        *pixConvertColorToSubpixelRGB()
+*
+*      Setting neutral point for min/max boost conversion to gray
+*          void         l_setNeutralBoostVal()
+* </pre>
+*/
+#ifdef HAVE_CONFIG_H
+#include <config_auto.h>
+#endif  /* HAVE_CONFIG_H */
+#include <string.h>
+#include <math.h>
+#include "allheaders.h"
+/* ------- Set neutral point for min/max boost conversion to gray ------ */
+/* Call l_setNeutralBoostVal() to change this */
+static l_int32  var_NEUTRAL_BOOST_VAL = 180;
+#ifndef  NO_CONSOLE_IO
+#define DEBUG_CONVERT_TO_COLORMAP  0
+#define DEBUG_UNROLLING 0
+#endif   /* ~NO_CONSOLE_IO */
+/*-------------------------------------------------------------*
+*     Conversion from 8 bpp grayscale to 1, 2 4 and 8 bpp     *
+*-------------------------------------------------------------*/
+/*!
+* \brief   pixThreshold8()
+*
+* \param[in]    pixs       8 bpp grayscale
+* \param[in]    d          destination depth: 1, 2, 4 or 8
+* \param[in]    nlevels    number of levels to be used for colormap
+* \param[in]    cmapflag   1 if makes colormap; 0 otherwise
+* \return  pixd thresholded with standard dest thresholds,
+*              or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This uses, by default, equally spaced "target" values
+*          that depend on the number of levels, with thresholds
+*          halfway between.  For N levels, with separation (N-1)/255,
+*          there are N-1 fixed thresholds.
+*      (2) For 1 bpp destination, the number of levels can only be 2
+*          and if a cmap is made, black is (0,0,0) and white
+*          is (255,255,255), which is opposite to the convention
+*          without a colormap.
+*      (3) For 1, 2 and 4 bpp, the nlevels arg is used if a colormap
+*          is made; otherwise, we take the most significant bits
+*          from the src that will fit in the dest.
+*      (4) For 8 bpp, the input pixs is quantized to nlevels.  The
+*          dest quantized with that mapping, either through a colormap
+*          table or directly with 8 bit values.
+*      (5) Typically you should not use make a colormap for 1 bpp dest.
+*      (6) This is not dithering.  Each pixel is treated independently.
+* </pre>
+*/
+PIX *
+pixThreshold8(PIX     *pixs,
+l_int32  d,
+l_int32  nlevels,
+l_int32  cmapflag)
+{
+PIX       *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 8)
+return (PIX *)ERROR_PTR("pixs not 8 bpp", __func__, NULL);
+if (cmapflag && nlevels < 2)
+return (PIX *)ERROR_PTR("nlevels must be at least 2", __func__, NULL);
+switch (d) {
+case 1:
+pixd = pixThresholdToBinary(pixs, 128);
+if (cmapflag) {
+cmap = pixcmapCreateLinear(1, 2);
+pixSetColormap(pixd, cmap);
+}
+break;
+case 2:
+pixd = pixThresholdTo2bpp(pixs, nlevels, cmapflag);
+break;
+case 4:
+pixd = pixThresholdTo4bpp(pixs, nlevels, cmapflag);
+break;
+case 8:
+pixd = pixThresholdOn8bpp(pixs, nlevels, cmapflag);
+break;
+default:
+return (PIX *)ERROR_PTR("d must be in {1,2,4,8}", __func__, NULL);
+}
+if (!pixd)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*-------------------------------------------------------------*
+*               Conversion from colormapped pix               *
+*-------------------------------------------------------------*/
+/*!
+* \brief   pixRemoveColormapGeneral()
+*
+* \param[in]    pixs      any depth, with or without colormap
+* \param[in]    type      REMOVE_CMAP_TO_BINARY,
+*                         REMOVE_CMAP_TO_GRAYSCALE,
+*                         REMOVE_CMAP_TO_FULL_COLOR,
+*                         REMOVE_CMAP_WITH_ALPHA,
+*                         REMOVE_CMAP_BASED_ON_SRC
+* \param[in]    ifnocmap  L_CLONE, L_COPY
+* \return  pixd always a new pix; without colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Convenience function that allows choice between returning
+*          a clone or a copy if pixs does not have a colormap.
+*      (2) See pixRemoveColormap().
+* </pre>
+*/
+PIX *
+pixRemoveColormapGeneral(PIX     *pixs,
+l_int32  type,
+l_int32  ifnocmap)
+{
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (ifnocmap != L_CLONE && ifnocmap != L_COPY)
+return (PIX *)ERROR_PTR("invalid value for ifnocmap", __func__, NULL);
+if (pixGetColormap(pixs))
+return pixRemoveColormap(pixs, type);
+if (ifnocmap == L_CLONE)
+return pixClone(pixs);
+else
+return pixCopy(NULL, pixs);
+}
+/*!
+* \brief   pixRemoveColormap()
+*
+* \param[in]    pixs   see restrictions below
+* \param[in]    type   REMOVE_CMAP_TO_BINARY,
+*                      REMOVE_CMAP_TO_GRAYSCALE,
+*                      REMOVE_CMAP_TO_FULL_COLOR,
+*                      REMOVE_CMAP_WITH_ALPHA,
+*                      REMOVE_CMAP_BASED_ON_SRC
+* \return  pixd without colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If pixs does not have a colormap, a clone is returned.
+*      (2) Otherwise, the input pixs is restricted to 1, 2, 4 or 8 bpp.
+*      (3) Use REMOVE_CMAP_TO_BINARY only on 1 bpp pix.
+*      (4) For grayscale conversion from RGB, use a weighted average
+*          of RGB values, and always return an 8 bpp pix, regardless
+*          of whether the input pixs depth is 2, 4 or 8 bpp.
+*      (5) REMOVE_CMAP_TO_FULL_COLOR ignores the alpha component and
+*          returns a 32 bpp pix with spp == 3 and the alpha bytes are 0.
+*      (6) For REMOVE_CMAP_BASED_ON_SRC, if there is no color, this
+*          returns either a 1 bpp or 8 bpp grayscale pix.
+*          If there is color, this returns a 32 bpp pix, with either:
+*           * 3 spp, if the alpha values are all 255 (opaque), or
+*           * 4 spp (preserving the alpha), if any alpha values are not 255.
+* </pre>
+*/
+PIX *
+pixRemoveColormap(PIX     *pixs,
+l_int32  type)
+{
+l_int32    sval, rval, gval, bval, val0, val1;
+l_int32    i, j, k, w, h, d, wpls, wpld, ncolors, nalloc, count;
+l_int32    opaque, colorfound, blackwhite;
+l_int32   *rmap, *gmap, *bmap, *amap;
+l_uint32  *datas, *lines, *datad, *lined, *lut, *graymap;
+l_uint32   sword, dword;
+PIXCMAP   *cmap;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if ((cmap = pixGetColormap(pixs)) == NULL)
+return pixClone(pixs);
+if (type != REMOVE_CMAP_TO_BINARY &&
+type != REMOVE_CMAP_TO_GRAYSCALE &&
+type != REMOVE_CMAP_TO_FULL_COLOR &&
+type != REMOVE_CMAP_WITH_ALPHA &&
+type != REMOVE_CMAP_BASED_ON_SRC) {
+L_WARNING("Invalid type; converting based on src\n", __func__);
+type = REMOVE_CMAP_BASED_ON_SRC;
+}
+pixGetDimensions(pixs, &w, &h, &d);
+if (d != 1 && d != 2 && d != 4 && d != 8)
+return (PIX *)ERROR_PTR("pixs must be {1,2,4,8} bpp", __func__, NULL);
+ncolors = pixcmapGetCount(cmap);
+nalloc = 1 << d;  /* allocate for max size in case of pixel corruption */
+if (ncolors > nalloc)
+return (PIX *)ERROR_PTR("too many colors for pixel depth",
+__func__, NULL);
+if (pixcmapToArrays(cmap, &rmap, &gmap, &bmap, &amap))
+return (PIX *)ERROR_PTR("colormap arrays not made", __func__, NULL);
+if (d != 1 && type == REMOVE_CMAP_TO_BINARY) {
+L_WARNING("not 1 bpp; can't remove cmap to binary\n", __func__);
+type = REMOVE_CMAP_BASED_ON_SRC;
+}
+/* Select output type depending on colormap content */
+if (type == REMOVE_CMAP_BASED_ON_SRC) {
+pixcmapIsOpaque(cmap, &opaque);
+pixcmapHasColor(cmap, &colorfound);
+pixcmapIsBlackAndWhite(cmap, &blackwhite);
+if (!opaque) {  /* save the alpha */
+type = REMOVE_CMAP_WITH_ALPHA;
+} else if (colorfound) {
+type = REMOVE_CMAP_TO_FULL_COLOR;
+} else {  /* opaque and no color */
+if (d == 1 && blackwhite)  /* can binarize without loss */
+type = REMOVE_CMAP_TO_BINARY;
+else
+type = REMOVE_CMAP_TO_GRAYSCALE;
+}
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if (type == REMOVE_CMAP_TO_BINARY) {
+if ((pixd = pixCopy(NULL, pixs)) == NULL) {
+L_ERROR("pixd not made\n", __func__);
+goto cleanup_arrays;
+}
+pixcmapGetColor(cmap, 0, &rval, &gval, &bval);
+val0 = rval + gval + bval;
+pixcmapGetColor(cmap, 1, &rval, &gval, &bval);
+val1 = rval + gval + bval;
+if (val0 < val1)  /* photometrically inverted from standard */
+pixInvert(pixd, pixd);
+pixDestroyColormap(pixd);
+} else if (type == REMOVE_CMAP_TO_GRAYSCALE) {
+if ((pixd = pixCreate(w, h, 8)) == NULL) {
+L_ERROR("pixd not made\n", __func__);
+goto cleanup_arrays;
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+graymap = (l_uint32 *)LEPT_CALLOC(nalloc, sizeof(l_uint32));
+for (i = 0; i < ncolors; i++) {
+graymap[i] = (l_uint32)(L_RED_WEIGHT * rmap[i] +
+L_GREEN_WEIGHT * gmap[i] +
+L_BLUE_WEIGHT * bmap[i] + 0.5);
+}
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+switch (d)   /* depth test above; no default permitted */
+{
+case 8:
+/* Unrolled 4x */
+for (j = 0, count = 0; j + 3 < w; j += 4, count++) {
+sword = lines[count];
+dword = (graymap[(sword >> 24) & 0xff] << 24) |
+(graymap[(sword >> 16) & 0xff] << 16) |
+(graymap[(sword >> 8) & 0xff] << 8) |
+graymap[sword & 0xff];
+lined[count] = dword;
+}
+/* Cleanup partial word */
+for (; j < w; j++) {
+sval = GET_DATA_BYTE(lines, j);
+gval = graymap[sval];
+SET_DATA_BYTE(lined, j, gval);
+}
+#if DEBUG_UNROLLING
+#define CHECK_VALUE(a, b, c) if (GET_DATA_BYTE(a, b) != c) { \
+lept_stderr("Error: mismatch at %d, %d vs %d\n", \
+j, GET_DATA_BYTE(a, b), c); }
+for (j = 0; j < w; j++) {
+sval = GET_DATA_BYTE(lines, j);
+gval = graymap[sval];
+CHECK_VALUE(lined, j, gval);
+}
+#endif
+break;
+case 4:
+/* Unrolled 8x */
+for (j = 0, count = 0; j + 7 < w; j += 8, count++) {
+sword = lines[count];
+dword = (graymap[(sword >> 28) & 0xf] << 24) |
+(graymap[(sword >> 24) & 0xf] << 16) |
+(graymap[(sword >> 20) & 0xf] << 8) |
+graymap[(sword >> 16) & 0xf];
+lined[2 * count] = dword;
+dword = (graymap[(sword >> 12) & 0xf] << 24) |
+(graymap[(sword >> 8) & 0xf] << 16) |
+(graymap[(sword >> 4) & 0xf] << 8) |
+graymap[sword & 0xf];
+lined[2 * count + 1] = dword;
+}
+/* Cleanup partial word */
+for (; j < w; j++) {
+sval = GET_DATA_QBIT(lines, j);
+gval = graymap[sval];
+SET_DATA_BYTE(lined, j, gval);
+}
+#if DEBUG_UNROLLING
+for (j = 0; j < w; j++) {
+sval = GET_DATA_QBIT(lines, j);
+gval = graymap[sval];
+CHECK_VALUE(lined, j, gval);
+}
+#endif
+break;
+case 2:
+/* Unrolled 16x */
+for (j = 0, count = 0; j + 15 < w; j += 16, count++) {
+sword = lines[count];
+dword = (graymap[(sword >> 30) & 0x3] << 24) |
+(graymap[(sword >> 28) & 0x3] << 16) |
+(graymap[(sword >> 26) & 0x3] << 8) |
+graymap[(sword >> 24) & 0x3];
+lined[4 * count] = dword;
+dword = (graymap[(sword >> 22) & 0x3] << 24) |
+(graymap[(sword >> 20) & 0x3] << 16) |
+(graymap[(sword >> 18) & 0x3] << 8) |
+graymap[(sword >> 16) & 0x3];
+lined[4 * count + 1] = dword;
+dword = (graymap[(sword >> 14) & 0x3] << 24) |
+(graymap[(sword >> 12) & 0x3] << 16) |
+(graymap[(sword >> 10) & 0x3] << 8) |
+graymap[(sword >> 8) & 0x3];
+lined[4 * count + 2] = dword;
+dword = (graymap[(sword >> 6) & 0x3] << 24) |
+(graymap[(sword >> 4) & 0x3] << 16) |
+(graymap[(sword >> 2) & 0x3] << 8) |
+graymap[sword & 0x3];
+lined[4 * count + 3] = dword;
+}
+/* Cleanup partial word */
+for (; j < w; j++) {
+sval = GET_DATA_DIBIT(lines, j);
+gval = graymap[sval];
+SET_DATA_BYTE(lined, j, gval);
+}
+#if DEBUG_UNROLLING
+for (j = 0; j < w; j++) {
+sval = GET_DATA_DIBIT(lines, j);
+gval = graymap[sval];
+CHECK_VALUE(lined, j, gval);
+}
+#endif
+break;
+case 1:
+/* Unrolled 8x */
+for (j = 0, count = 0; j + 31 < w; j += 32, count++) {
+sword = lines[count];
+for (k = 0; k < 4; k++) {
+/* The top byte is always the relevant one */
+dword = (graymap[(sword >> 31) & 0x1] << 24) |
+(graymap[(sword >> 30) & 0x1] << 16) |
+(graymap[(sword >> 29) & 0x1] << 8) |
+graymap[(sword >> 28) & 0x1];
+lined[8 * count + 2 * k] = dword;
+dword = (graymap[(sword >> 27) & 0x1] << 24) |
+(graymap[(sword >> 26) & 0x1] << 16) |
+(graymap[(sword >> 25) & 0x1] << 8) |
+graymap[(sword >> 24) & 0x1];
+lined[8 * count + 2 * k + 1] = dword;
+sword <<= 8;  /* Move up the next byte */
+}
+}
+/* Cleanup partial word */
+for (; j < w; j++) {
+sval = GET_DATA_BIT(lines, j);
+gval = graymap[sval];
+SET_DATA_BYTE(lined, j, gval);
+}
+#if DEBUG_UNROLLING
+for (j = 0; j < w; j++) {
+sval = GET_DATA_BIT(lines, j);
+gval = graymap[sval];
+CHECK_VALUE(lined, j, gval);
+}
+#undef CHECK_VALUE
+#endif
+break;
+default:
+return NULL;
+}
+}
+if (graymap)
+LEPT_FREE(graymap);
+} else {  /* type == REMOVE_CMAP_TO_FULL_COLOR or REMOVE_CMAP_WITH_ALPHA */
+if ((pixd = pixCreate(w, h, 32)) == NULL) {
+L_ERROR("pixd not made\n", __func__);
+goto cleanup_arrays;
+}
+pixCopyInputFormat(pixd, pixs);
+pixCopyResolution(pixd, pixs);
+if (type == REMOVE_CMAP_WITH_ALPHA)
+pixSetSpp(pixd, 4);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+lut = (l_uint32 *)LEPT_CALLOC(nalloc, sizeof(l_uint32));
+for (i = 0; i < ncolors; i++) {
+if (type == REMOVE_CMAP_TO_FULL_COLOR)
+composeRGBPixel(rmap[i], gmap[i], bmap[i], lut + i);
+else  /* full color plus alpha */
+composeRGBAPixel(rmap[i], gmap[i], bmap[i], amap[i], lut + i);
+}
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+if (d == 8)
+sval = GET_DATA_BYTE(lines, j);
+else if (d == 4)
+sval = GET_DATA_QBIT(lines, j);
+else if (d == 2)
+sval = GET_DATA_DIBIT(lines, j);
+else  /* (d == 1) */
+sval = GET_DATA_BIT(lines, j);
+if (sval >= ncolors)
+L_WARNING("pixel value out of bounds\n", __func__);
+else
+lined[j] = lut[sval];
+}
+}
+LEPT_FREE(lut);
+}
+cleanup_arrays:
+LEPT_FREE(rmap);
+LEPT_FREE(gmap);
+LEPT_FREE(bmap);
+LEPT_FREE(amap);
+return pixd;
+}
+/*-------------------------------------------------------------*
+*              Add colormap losslessly (8 to 8)               *
+*-------------------------------------------------------------*/
+/*!
+* \brief   pixAddGrayColormap8()
+*
+* \param[in]    pixs   8 bpp
+* \return  0 if OK, 1 on error
+*
+* <pre>
+* Notes:
+*      (1) If pixs has a colormap, this is a no-op.
+* </pre>
+*/
+l_ok
+pixAddGrayColormap8(PIX  *pixs)
+{
+PIXCMAP  *cmap;
+if (!pixs || pixGetDepth(pixs) != 8)
+return ERROR_INT("pixs not defined or not 8 bpp", __func__, 1);
+if (pixGetColormap(pixs))
+return 0;
+cmap = pixcmapCreateLinear(8, 256);
+pixSetColormap(pixs, cmap);
+return 0;
+}
+/*!
+* \brief   pixAddMinimalGrayColormap8()
+*
+* \param[in]    pixs   8 bpp
+* \return  0 if OK, 1 on error
+*
+* <pre>
+* Notes:
+*      (1) This generates a colormapped version of the input image
+*          that has the same number of colormap entries as the
+*          input image has unique gray levels.
+* </pre>
+*/
+PIX *
+pixAddMinimalGrayColormap8(PIX  *pixs)
+{
+l_int32    ncolors, w, h, i, j, wpl1, wpld, index, val;
+l_int32   *inta, *revmap;
+l_uint32  *data1, *datad, *line1, *lined;
+PIX       *pix1, *pixd;
+PIXCMAP   *cmap;
+if (!pixs || pixGetDepth(pixs) != 8)
+return (PIX *)ERROR_PTR("pixs undefined or not 8 bpp", __func__, NULL);
+/* Eliminate the easy cases */
+pixNumColors(pixs, 1, &ncolors);
+cmap = pixGetColormap(pixs);
+if (cmap) {
+if (pixcmapGetCount(cmap) == ncolors)  /* irreducible */
+return pixCopy(NULL, pixs);
+else
+pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+} else {
+if (ncolors == 256) {
+pix1 = pixCopy(NULL, pixs);
+pixAddGrayColormap8(pix1);
+return pix1;
+}
+pix1 = pixClone(pixs);
+}
+/* Find the gray levels and make a reverse map */
+pixGetDimensions(pix1, &w, &h, NULL);
+data1 = pixGetData(pix1);
+wpl1 = pixGetWpl(pix1);
+inta = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32));
+for (i = 0; i < h; i++) {
+line1 = data1 + i * wpl1;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(line1, j);
+inta[val] = 1;
+}
+}
+cmap = pixcmapCreate(8);
+revmap = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32));
+for (i = 0, index = 0; i < 256; i++) {
+if (inta[i]) {
+pixcmapAddColor(cmap, i, i, i);
+revmap[i] = index++;
+}
+}
+/* Set all pixels in pixd to the colormap index */
+pixd = pixCreateTemplate(pix1);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+pixCopyResolution(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+line1 = data1 + i * wpl1;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(line1, j);
+SET_DATA_BYTE(lined, j, revmap[val]);
+}
+}
+pixDestroy(&pix1);
+LEPT_FREE(inta);
+LEPT_FREE(revmap);
+return pixd;
+}
+/*-------------------------------------------------------------*
+*            Conversion from RGB color to grayscale           *
+*-------------------------------------------------------------*/
+/*!
+* \brief   pixConvertRGBToLuminance()
+*
+* \param[in]    pixs   32 bpp RGB
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Use a standard luminance conversion.
+* </pre>
+*/
+PIX *
+pixConvertRGBToLuminance(PIX *pixs)
+{
+return pixConvertRGBToGray(pixs, 0.0, 0.0, 0.0);
+}
+/*!
+* \brief   pixConvertRGBToGrayGeneral()
+*
+* \param[in]    pixs           32 bpp RGB
+* \param[in]    type           color selection flag
+* \param[in]    rwt, gwt, bwt  ignored if type != L_SELECT_WEIGHTED;
+*                              if used, must sum to 1.0.
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) The color selection flag is one of: L_SELECT_RED, L_SELECT_GREEN,
+*          L_SELECT_BLUE, L_SELECT_MIN, L_SELECT_MAX, L_SELECT_AVERAGE,
+*          L_SELECT_HUE, L_SELECT_SATURATION, L_SELECT_WEIGHTED.
+*      (2) The weights, if used, must all be non-negative and must sum to 1.0.
+* </pre>
+*/
+PIX *
+pixConvertRGBToGrayGeneral(PIX       *pixs,
+l_int32    type,
+l_float32  rwt,
+l_float32  gwt,
+l_float32  bwt)
+{
+PIX  *pix1;
+if (!pixs || pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, NULL);
+if (type != L_SELECT_RED && type != L_SELECT_GREEN &&
+type != L_SELECT_BLUE && type != L_SELECT_MIN &&
+type != L_SELECT_MAX && type != L_SELECT_AVERAGE &&
+type != L_SELECT_HUE && type != L_SELECT_SATURATION &&
+type != L_SELECT_WEIGHTED)
+return (PIX *)ERROR_PTR("invalid type", __func__, NULL);
+if (type == L_SELECT_RED) {
+pix1 = pixGetRGBComponent(pixs, COLOR_RED);
+} else if (type == L_SELECT_GREEN) {
+pix1 = pixGetRGBComponent(pixs, COLOR_GREEN);
+} else if (type == L_SELECT_BLUE) {
+pix1 = pixGetRGBComponent(pixs, COLOR_BLUE);
+} else if (type == L_SELECT_MIN) {
+pix1 = pixConvertRGBToGrayMinMax(pixs, L_CHOOSE_MIN);
+} else if (type == L_SELECT_MAX) {
+pix1 = pixConvertRGBToGrayMinMax(pixs, L_CHOOSE_MAX);
+} else if (type == L_SELECT_AVERAGE) {
+pix1 = pixConvertRGBToGray(pixs, 0.34f, 0.33f, 0.33f);
+} else if (type == L_SELECT_HUE) {
+pix1 = pixConvertRGBToHue(pixs);
+} else if (type == L_SELECT_SATURATION) {
+pix1 = pixConvertRGBToSaturation(pixs);
+} else { /* L_SELECT_WEIGHTED */
+if (rwt < 0.0 || gwt < 0.0 || bwt < 0.0)
+return (PIX *)ERROR_PTR("weights not all >= 0.0", __func__, NULL);
+if (rwt + gwt + bwt != 1.0)
+return (PIX *)ERROR_PTR("weights don't sum to 1.0", __func__, NULL);
+pix1 = pixConvertRGBToGray(pixs, rwt, gwt, bwt);
+}
+return pix1;
+}
+/*!
+* \brief   pixConvertRGBToGray()
+*
+* \param[in]    pixs           32 bpp RGB
+* \param[in]    rwt, gwt, bwt  non-negative; these should add to 1.0,
+*                              or use 0.0 for default
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Use a weighted average of the RGB values.
+* </pre>
+*/
+PIX *
+pixConvertRGBToGray(PIX       *pixs,
+l_float32  rwt,
+l_float32  gwt,
+l_float32  bwt)
+{
+l_int32    i, j, w, h, wpls, wpld, val;
+l_uint32   word;
+l_uint32  *datas, *lines, *datad, *lined;
+l_float32  sum;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+if (rwt < 0.0 || gwt < 0.0 || bwt < 0.0)
+return (PIX *)ERROR_PTR("weights not all >= 0.0", __func__, NULL);
+/* Make sure the sum of weights is 1.0; otherwise, you can get
+* overflow in the gray value. */
+if (rwt == 0.0 && gwt == 0.0 && bwt == 0.0) {
+rwt = L_RED_WEIGHT;
+gwt = L_GREEN_WEIGHT;
+bwt = L_BLUE_WEIGHT;
+}
+sum = rwt + gwt + bwt;
+if (L_ABS(sum - 1.0) > 0.0001) {  /* maintain ratios with sum == 1.0 */
+L_WARNING("weights don't sum to 1; maintaining ratios\n", __func__);
+rwt = rwt / sum;
+gwt = gwt / sum;
+bwt = bwt / sum;
+}
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+word = *(lines + j);
+val = (l_int32)(rwt * ((word >> L_RED_SHIFT) & 0xff) +
+gwt * ((word >> L_GREEN_SHIFT) & 0xff) +
+bwt * ((word >> L_BLUE_SHIFT) & 0xff) + 0.5);
+SET_DATA_BYTE(lined, j, val);
+}
+}
+return pixd;
+}
+/*!
+* \brief   pixConvertRGBToGrayFast()
+*
+* \param[in]    pixs    32 bpp RGB
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This function should be used if speed of conversion
+*          is paramount, and the green channel can be used as
+*          a fair representative of the RGB intensity.  It is
+*          several times faster than pixConvertRGBToGray().
+*      (2) To combine RGB to gray conversion with subsampling,
+*          use pixScaleRGBToGrayFast() instead.
+* </pre>
+*/
+PIX *
+pixConvertRGBToGrayFast(PIX  *pixs)
+{
+l_int32    i, j, w, h, wpls, wpld, val;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++, lines++) {
+val = ((*lines) >> L_GREEN_SHIFT) & 0xff;
+SET_DATA_BYTE(lined, j, val);
+}
+}
+return pixd;
+}
+/*!
+* \brief   pixConvertRGBToGrayMinMax()
+*
+* \param[in]    pixs   32 bpp RGB
+* \param[in]    type   L_CHOOSE_MIN, L_CHOOSE_MAX, L_CHOOSE_MAXDIFF,
+*                      L_CHOOSE_MIN_BOOST, L_CHOOSE_MAX_BOOST
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This chooses various components or combinations of them,
+*          from the three RGB sample values.  In addition to choosing
+*          the min, max, and maxdiff (difference between max and min),
+*          this also allows boosting the min and max about a reference
+*          value.
+*      (2) The default reference value for boosting the min and max
+*          is 200.  This can be changed with l_setNeutralBoostVal()
+*      (3) The result with L_CHOOSE_MAXDIFF is surprisingly sensitive
+*          to a jpeg compression/decompression cycle with quality = 75.
+* </pre>
+*/
+PIX *
+pixConvertRGBToGrayMinMax(PIX     *pixs,
+l_int32  type)
+{
+l_int32    i, j, w, h, wpls, wpld, rval, gval, bval, val, minval, maxval;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+if (type != L_CHOOSE_MIN && type != L_CHOOSE_MAX &&
+type != L_CHOOSE_MAXDIFF && type != L_CHOOSE_MIN_BOOST &&
+type != L_CHOOSE_MAX_BOOST)
+return (PIX *)ERROR_PTR("invalid type", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+extractRGBValues(lines[j], &rval, &gval, &bval);
+if (type == L_CHOOSE_MIN || type == L_CHOOSE_MIN_BOOST) {
+val = L_MIN(rval, gval);
+val = L_MIN(val, bval);
+if (type == L_CHOOSE_MIN_BOOST)
+val = L_MIN(255, (val * val) / var_NEUTRAL_BOOST_VAL);
+} else if (type == L_CHOOSE_MAX || type == L_CHOOSE_MAX_BOOST) {
+val = L_MAX(rval, gval);
+val = L_MAX(val, bval);
+if (type == L_CHOOSE_MAX_BOOST)
+val = L_MIN(255, (val * val) / var_NEUTRAL_BOOST_VAL);
+} else {  /* L_CHOOSE_MAXDIFF */
+minval = L_MIN(rval, gval);
+minval = L_MIN(minval, bval);
+maxval = L_MAX(rval, gval);
+maxval = L_MAX(maxval, bval);
+val = maxval - minval;
+}
+SET_DATA_BYTE(lined, j, val);
+}
+}
+return pixd;
+}
+/*!
+* \brief   pixConvertRGBToGraySatBoost()
+*
+* \param[in]    pixs    32 bpp rgb
+* \param[in]    refval  between 1 and 255; typ. less than 128
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This returns the max component value, boosted by
+*          the saturation. The maximum boost occurs where
+*          the maximum component value is equal to some reference value.
+*          This particular weighting is due to Dany Qumsiyeh.
+*      (2) For gray pixels (zero saturation), this returns
+*          the intensity of any component.
+*      (3) For fully saturated pixels ('fullsat'), this rises linearly
+*          with the max value and has a slope equal to 255 divided
+*          by the reference value; for a max value greater than
+*          the reference value, it is clipped to 255.
+*      (4) For saturation values in between, the output is a linear
+*          combination of (2) and (3), weighted by saturation.
+*          It falls between these two curves, and does not exceed 255.
+*      (5) This can be useful for distinguishing an object that has nonzero
+*          saturation from a gray background.  For this, the refval
+*          should be chosen near the expected value of the background,
+*          to achieve maximum saturation boost there.
+* </pre>
+*/
+PIX  *
+pixConvertRGBToGraySatBoost(PIX     *pixs,
+l_int32  refval)
+{
+l_int32     w, h, d, i, j, wplt, wpld;
+l_int32     rval, gval, bval, sval, minrg, maxrg, min, max, delta;
+l_int32     fullsat, newval;
+l_float32  *invmax, *ratio;
+l_uint32   *linet, *lined, *datat, *datad;
+PIX        *pixt, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, &d);
+if (d != 32 && !pixGetColormap(pixs))
+return (PIX *)ERROR_PTR("pixs not cmapped or rgb", __func__, NULL);
+if (refval < 1 || refval > 255)
+return (PIX *)ERROR_PTR("refval not in [1 ... 255]", __func__, NULL);
+pixt = pixRemoveColormap(pixs, REMOVE_CMAP_TO_FULL_COLOR);
+pixd = pixCreate(w, h, 8);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+wplt = pixGetWpl(pixt);
+datat = pixGetData(pixt);
+wpld = pixGetWpl(pixd);
+datad = pixGetData(pixd);
+invmax = (l_float32 *)LEPT_CALLOC(256, sizeof(l_float32));
+ratio = (l_float32 *)LEPT_CALLOC(256, sizeof(l_float32));
+for (i = 1; i < 256; i++) {  /* i == 0  --> delta = sval = newval = 0 */
+invmax[i] = 1.0f / (l_float32)i;
+ratio[i] = (l_float32)i / (l_float32)refval;
+}
+for (i = 0; i < h; i++) {
+linet = datat + i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+extractRGBValues(linet[j], &rval, &gval, &bval);
+minrg = L_MIN(rval, gval);
+min = L_MIN(minrg, bval);
+maxrg = L_MAX(rval, gval);
+max = L_MAX(maxrg, bval);
+delta = max - min;
+if (delta == 0)  /* gray; no chroma */
+sval = 0;
+else
+sval = (l_int32)(255. * (l_float32)delta * invmax[max] + 0.5);
+fullsat = L_MIN(255, 255 * ratio[max]);
+newval = (sval * fullsat + (255 - sval) * max) / 255;
+SET_DATA_BYTE(lined, j, newval);
+}
+}
+pixDestroy(&pixt);
+LEPT_FREE(invmax);
+LEPT_FREE(ratio);
+return pixd;
+}
+/*!
+* \brief   pixConvertRGBToGrayArb()
+*
+* \param[in]    pixs        32 bpp RGB
+* \param[in]    rc, gc, bc  arithmetic factors; can be negative
+* \return  8 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This converts to gray using an arbitrary linear combination
+*          of the rgb color components.  It differs from pixConvertToGray(),
+*          which uses only positive coefficients that sum to 1.
+*      (2) The gray output values are clipped to 0 and 255.
+* </pre>
+*/
+PIX *
+pixConvertRGBToGrayArb(PIX       *pixs,
+l_float32  rc,
+l_float32  gc,
+l_float32  bc)
+{
+l_int32    i, j, w, h, wpls, wpld, rval, gval, bval, val;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+if (rc <= 0 && gc <= 0 && bc <= 0)
+return (PIX *)ERROR_PTR("all coefficients <= 0", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+extractRGBValues(lines[j], &rval, &gval, &bval);
+val = (l_int32)(rc * rval + gc * gval + bc * bval);
+val = L_MIN(255, L_MAX(0, val));
+SET_DATA_BYTE(lined, j, val);
+}
+}
+return pixd;
+}
+/*!
+* \brief   pixConvertRGBToBinaryArb()
+*
+* \param[in]    pixs        32 bpp RGB
+* \param[in]    rc, gc, bc  arithmetic factors; can be negative
+* \param[in]    thresh      binarization threshold
+* \param[in]    relation    L_SELECT_IF_LT, L_SELECT_IF_GT
+*                           L_SELECT_IF_LTE, L_SELECT_IF_GTE
+* \return  1 bpp pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This makes a 1 bpp mask from an RGB image, using an arbitrary
+*          linear combination of the rgb color components, along with
+*          a threshold and a selection choice of the gray value relative
+*          to %thresh.
+* </pre>
+*/
+PIX *
+pixConvertRGBToBinaryArb(PIX       *pixs,
+l_float32  rc,
+l_float32  gc,
+l_float32  bc,
+l_int32    thresh,
+l_int32    relation)
+{
+l_int32  threshold;
+PIX     *pix1, *pix2;
+if (!pixs || pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, NULL);
+if (rc <= 0 && gc <= 0 && bc <= 0)
+return (PIX *)ERROR_PTR("all coefficients <= 0", __func__, NULL);
+if (relation != L_SELECT_IF_LT && relation != L_SELECT_IF_GT &&
+relation != L_SELECT_IF_LTE && relation != L_SELECT_IF_GTE)
+return (PIX *)ERROR_PTR("invalid relation", __func__, NULL);
+pix1 = pixConvertRGBToGrayArb(pixs, rc, gc, bc);
+threshold = (relation == L_SELECT_IF_LTE || relation == L_SELECT_IF_GT) ?
+thresh : thresh + 1;
+pix2 = pixThresholdToBinary(pix1, threshold);
+if (relation == L_SELECT_IF_GT || relation == L_SELECT_IF_GTE)
+pixInvert(pix2, pix2);
+pixDestroy(&pix1);
+return pix2;
+}
+/*---------------------------------------------------------------------------*
+*                  Conversion from grayscale to colormap                    *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertGrayToColormap()
+*
+* \param[in]    pixs    2, 4 or 8 bpp grayscale
+* \return  pixd 2, 4 or 8 bpp with colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a simple interface for adding a colormap to a
+*          2, 4 or 8 bpp grayscale image without causing any
+*          quantization.  There is some similarity to operations
+*          in grayquant.c, such as pixThresholdOn8bpp(), where
+*          the emphasis is on quantization with an arbitrary number
+*          of levels, and a colormap is an option.
+*      (2) Returns a copy if pixs already has a colormap.
+*      (3) For 8 bpp src, this is a lossless transformation.
+*      (4) For 2 and 4 bpp src, this generates a colormap that
+*          assumes full coverage of the gray space, with equally spaced
+*          levels: 4 levels for d = 2 and 16 levels for d = 4.
+*      (5) In all cases, the depth of the dest is the same as the src.
+* </pre>
+*/
+PIX *
+pixConvertGrayToColormap(PIX  *pixs)
+{
+l_int32    d;
+PIX       *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 2 && d != 4 && d != 8)
+return (PIX *)ERROR_PTR("pixs not 2, 4 or 8 bpp", __func__, NULL);
+if (pixGetColormap(pixs)) {
+L_INFO("pixs already has a colormap\n", __func__);
+return pixCopy(NULL, pixs);
+}
+if (d == 8)  /* lossless conversion */
+return pixConvertGrayToColormap8(pixs, 2);
+/* Build a cmap with equally spaced target values over the
+* full 8 bpp range. */
+pixd = pixCopy(NULL, pixs);
+cmap = pixcmapCreateLinear(d, 1 << d);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvertGrayToColormap8()
+*
+* \param[in]    pixs       8 bpp grayscale
+* \param[in]    mindepth   of pixd; valid values are 2, 4 and 8
+* \return  pixd 2, 4 or 8 bpp with colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Returns a copy if pixs already has a colormap.
+*      (2) This is a lossless transformation; there is no quantization.
+*          We compute the number of different gray values in pixs,
+*          and construct a colormap that has exactly these values.
+*      (3) 'mindepth' is the minimum depth of pixd.  If mindepth == 8,
+*          pixd will always be 8 bpp.  Let the number of different
+*          gray values in pixs be ngray.  If mindepth == 4, we attempt
+*          to save pixd as a 4 bpp image, but if ngray > 16,
+*          pixd must be 8 bpp.  Likewise, if mindepth == 2,
+*          the depth of pixd will be 2 if ngray <= 4 and 4 if ngray > 4
+*          but <= 16.
+* </pre>
+*/
+PIX *
+pixConvertGrayToColormap8(PIX     *pixs,
+l_int32  mindepth)
+{
+l_int32    ncolors, w, h, depth, i, j, wpls, wpld;
+l_int32    index, num, val, newval;
+l_int32    array[256];
+l_uint32  *lines, *lined, *datas, *datad;
+NUMA      *na;
+PIX       *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 8)
+return (PIX *)ERROR_PTR("pixs not 8 bpp", __func__, NULL);
+if (mindepth != 2 && mindepth != 4 && mindepth != 8) {
+L_WARNING("invalid value of mindepth; setting to 8\n", __func__);
+mindepth = 8;
+}
+if (pixGetColormap(pixs)) {
+L_INFO("pixs already has a colormap\n", __func__);
+return pixCopy(NULL, pixs);
+}
+na = pixGetGrayHistogram(pixs, 1);
+numaGetCountRelativeToZero(na, L_GREATER_THAN_ZERO, &ncolors);
+if (mindepth == 8 || ncolors > 16)
+depth = 8;
+else if (mindepth == 4 || ncolors > 4)
+depth = 4;
+else
+depth = 2;
+pixGetDimensions(pixs, &w, &h, NULL);
+pixd = pixCreate(w, h, depth);
+cmap = pixcmapCreate(depth);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+pixCopyResolution(pixd, pixs);
+index = 0;
+for (i = 0; i < 256; i++) {
+array[i] = 0;  /* only to quiet the static checker */
+numaGetIValue(na, i, &num);
+if (num > 0) {
+pixcmapAddColor(cmap, i, i, i);
+array[i] = index;
+index++;
+}
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(lines, j);
+newval = array[val];
+if (depth == 2)
+SET_DATA_DIBIT(lined, j, newval);
+else if (depth == 4)
+SET_DATA_QBIT(lined, j, newval);
+else  /* depth == 8 */
+SET_DATA_BYTE(lined, j, newval);
+}
+}
+numaDestroy(&na);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                Colorizing conversion from grayscale to color              *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixColorizeGray()
+*
+* \param[in]    pixs      8 bpp gray; 2, 4 or 8 bpp colormapped
+* \param[in]    color     32 bit rgba pixel
+* \param[in]    cmapflag  1 for result to have colormap; 0 for RGB
+* \return  pixd 8 bpp colormapped or 32 bpp rgb, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This applies the specific color to the grayscale image.
+*      (2) If pixs already has a colormap, it is removed to gray
+*          before colorizing.
+* </pre>
+*/
+PIX *
+pixColorizeGray(PIX      *pixs,
+l_uint32  color,
+l_int32   cmapflag)
+{
+l_int32    i, j, w, h, wplt, wpld, val8;
+l_uint32  *datad, *datat, *lined, *linet, *tab;
+PIX       *pixt, *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 8 && !pixGetColormap(pixs))
+return (PIX *)ERROR_PTR("pixs not 8 bpp or cmapped", __func__, NULL);
+if (pixGetColormap(pixs))
+pixt = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+else
+pixt = pixClone(pixs);
+cmap = pixcmapGrayToColor(color);
+if (cmapflag) {
+pixd = pixCopy(NULL, pixt);
+pixSetColormap(pixd, cmap);
+pixDestroy(&pixt);
+return pixd;
+}
+/* Make an RGB pix */
+pixcmapToRGBTable(cmap, &tab, NULL);
+pixGetDimensions(pixt, &w, &h, NULL);
+pixd = pixCreate(w, h, 32);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+datat = pixGetData(pixt);
+wplt = pixGetWpl(pixt);
+for (i = 0; i < h; i++) {
+lined = datad + i * wpld;
+linet = datat + i * wplt;
+for (j = 0; j < w; j++) {
+val8 = GET_DATA_BYTE(linet, j);
+lined[j] = tab[val8];
+}
+}
+pixDestroy(&pixt);
+pixcmapDestroy(&cmap);
+LEPT_FREE(tab);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                    Conversion from RGB color to colormap                  *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertRGBToColormap()
+*
+* \param[in]    pixs       32 bpp rgb
+* \param[in]    ditherflag  1 to dither, 0 otherwise
+* \return  pixd 2, 4 or 8 bpp with colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This function has two relatively simple modes of color
+*          quantization:
+*            (a) If the image is made orthographically and has not more
+*                than 256 'colors' at the level 4 octcube leaves,
+*                it is quantized nearly exactly.  The ditherflag
+*                is ignored.
+*            (b) Most natural images have more than 256 different colors;
+*                in that case we use adaptive octree quantization,
+*                with dithering if requested.
+*      (2) If there are not more than 256 occupied level 4 octcubes,
+*          the color in the colormap that represents all pixels in
+*          one of those octcubes is given by the first pixel that
+*          falls into that octcube.
+*      (3) Dithering gives better visual results on images where
+*          there is a color wash (a slow variation of color), but it
+*          is about twice as slow and results in significantly larger
+*          files when losslessly compressed (e.g., into png).
+* </pre>
+*/
+PIX *
+pixConvertRGBToColormap(PIX     *pixs,
+l_int32  ditherflag)
+{
+l_int32  ncolors;
+NUMA    *na;
+PIX     *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+if (pixGetSpp(pixs) == 4)
+L_WARNING("pixs has alpha; removing\n", __func__);
+/* Get the histogram and count the number of occupied level 4
+* leaf octcubes.  We don't yet know if this is the number of
+* actual colors, but if it's not, all pixels falling into
+* the same leaf octcube will be assigned to the color of the
+* first pixel that lands there. */
+na = pixOctcubeHistogram(pixs, 4, &ncolors);
+/* If 256 or fewer occupied leaf octcubes, quantize to those octcubes */
+if (ncolors <= 256) {
+pixd = pixFewColorsOctcubeQuant2(pixs, 4, na, ncolors, NULL);
+pixCopyInputFormat(pixd, pixs);
+numaDestroy(&na);
+return pixd;
+}
+/* There are too many occupied leaf octcubes to be represented
+* directly in a colormap.  Fall back to octree quantization,
+* optionally with dithering. */
+numaDestroy(&na);
+if (ditherflag)
+L_INFO("More than 256 colors; using octree quant with dithering\n",
+__func__);
+else
+L_INFO("More than 256 colors; using octree quant; no dithering\n",
+__func__);
+return pixOctreeColorQuant(pixs, 240, ditherflag);
+}
+/*---------------------------------------------------------------------------*
+*                     Conversion from colormap to 1 bpp                     *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertCmapTo1()
+*
+* \param[in]    pixs   cmapped
+* \return  pixd 1 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is an extreme color quantizer.  It decides which
+*          colors map to FG (black) and which to BG (white).
+*      (2) This uses two heuristics to make the decision:
+*          (a) colors similar to each other are likely to be in the same class
+*          (b) there is usually much less FG than BG.
+* </pre>
+*/
+PIX *
+pixConvertCmapTo1(PIX  *pixs)
+{
+l_int32    i, j, nc, w, h, imin, imax, factor, wpl1, wpld;
+l_int32    index, rmin, gmin, bmin, rmax, gmax, bmax, dmin, dmax;
+l_float32  minfract, ifract;
+l_int32   *lut;
+l_uint32  *line1, *lined, *data1, *datad;
+NUMA      *na1, *na2;  /* histograms */
+PIX       *pix1, *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if ((cmap = pixGetColormap(pixs)) == NULL)
+return (PIX *)ERROR_PTR("no colormap", __func__, NULL);
+/* Select target colors for the two classes.  Find the
+* colors with smallest and largest average component values.
+* The smallest is class 0 and the largest is class 1. */
+pixcmapGetRangeValues(cmap, L_SELECT_AVERAGE, NULL, NULL, &imin, &imax);
+pixcmapGetColor(cmap, imin, &rmin, &gmin, &bmin);
+pixcmapGetColor(cmap, imax, &rmax, &gmax, &bmax);
+nc = pixcmapGetCount(cmap);
+/* Assign colors to the two classes.  The histogram is
+* initialized to 0, so any colors not found when computing
+* the sampled histogram will get zero weight in minfract. */
+if ((lut = (l_int32 *)LEPT_CALLOC(nc, sizeof(l_int32))) == NULL)
+return (PIX *)ERROR_PTR("calloc fail for lut", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+factor = L_MAX(1, (l_int32)sqrt((l_float64)(w * h) / 50000. + 0.5));
+na1 = pixGetCmapHistogram(pixs, factor);
+na2 = numaNormalizeHistogram(na1, 1.0);
+minfract = 0.0;
+for (i = 0; i < nc; i++) {
+numaGetFValue(na2, i, &ifract);
+pixcmapGetDistanceToColor(cmap, i, rmin, gmin, bmin, &dmin);
+pixcmapGetDistanceToColor(cmap, i, rmax, gmax, bmax, &dmax);
+if (dmin < dmax) {  /* closer to dark extreme value */
+lut[i] = 1;  /* black pixel in 1 bpp image */
+minfract += ifract;
+}
+}
+numaDestroy(&na1);
+numaDestroy(&na2);
+/* Generate the output binarized image */
+pix1 = pixConvertTo8(pixs, 1);
+pixd = pixCreate(w, h, 1);
+data1 = pixGetData(pix1);
+datad = pixGetData(pixd);
+wpl1 = pixGetWpl(pix1);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+line1 = data1 + i * wpl1;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+index = GET_DATA_BYTE(line1, j);
+if (lut[index] == 1) SET_DATA_BIT(lined, j);
+}
+}
+pixDestroy(&pix1);
+LEPT_FREE(lut);
+/* We expect minfract (the dark colors) to be less than 0.5.
+* If that is not the case, invert pixd. */
+if (minfract > 0.5) {
+L_INFO("minfract = %5.3f; inverting\n", __func__, minfract);
+pixInvert(pixd, pixd);
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*        Quantization for relatively small number of colors in source       *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixQuantizeIfFewColors()
+*
+* \param[in]    pixs           8 bpp gray or 32 bpp rgb
+* \param[in]    maxcolors      max number of colors allowed to be returned
+*                              from pixColorsForQuantization();
+*                              use 0 for default
+* \param[in]    mingraycolors  min number of gray levels that a grayscale
+*                              image is quantized to; use 0 for default
+* \param[in]    octlevel       for octcube quantization: 3 or 4
+* \param[out]   ppixd          2,4 or 8 bpp quantized; null if too many colors
+* \return  0 if OK, 1 on error or if pixs can't be quantized into
+*              a small number of colors.
+*
+* <pre>
+* Notes:
+*      (1) This is a wrapper that tests if the pix can be quantized
+*          with good quality using a small number of colors.  If so,
+*          it does the quantization, defining a colormap and using
+*          pixels whose value is an index into the colormap.
+*      (2) If the image has color, it is quantized with 8 bpp pixels.
+*          If the image is essentially grayscale, the pixels are
+*          either 4 or 8 bpp, depending on the size of the required
+*          colormap.
+*      (3) %octlevel = 4 generates a larger colormap and larger
+*          compressed image than %octlevel = 3.  If image quality is
+*          important, you should use %octlevel = 4.
+*      (4) If the image already has a colormap, it returns a clone.
+* </pre>
+*/
+l_ok
+pixQuantizeIfFewColors(PIX     *pixs,
+l_int32  maxcolors,
+l_int32  mingraycolors,
+l_int32  octlevel,
+PIX    **ppixd)
+{
+l_int32  d, ncolors, iscolor, graycolors;
+PIX     *pixg, *pixd;
+if (!ppixd)
+return ERROR_INT("&pixd not defined", __func__, 1);
+*ppixd = NULL;
+if (!pixs)
+return ERROR_INT("pixs not defined", __func__, 1);
+d = pixGetDepth(pixs);
+if (d != 8 && d != 32)
+return ERROR_INT("pixs not defined", __func__, 1);
+if (pixGetColormap(pixs) != NULL) {
+*ppixd = pixClone(pixs);
+return 0;
+}
+if (maxcolors <= 0)
+maxcolors = 15;  /* default */
+if (maxcolors > 50)
+L_WARNING("maxcolors > 50; very large!\n", __func__);
+if (mingraycolors <= 0)
+mingraycolors = 10;  /* default */
+if (mingraycolors > 30)
+L_WARNING("mingraycolors > 30; very large!\n", __func__);
+if (octlevel != 3 && octlevel != 4) {
+L_WARNING("invalid octlevel; setting to 3\n", __func__);
+octlevel = 3;
+}
+/* Test the number of colors.  For color, the octcube leaves
+* are at level 4. */
+pixColorsForQuantization(pixs, 0, &ncolors, &iscolor, 0);
+if (ncolors > maxcolors)
+return ERROR_INT("too many colors", __func__, 1);
+/* Quantize!
+*  (1) For color:
+*      If octlevel == 4, try to quantize to an octree where
+*      the octcube leaves are at level 4. If that fails,
+*      back off to level 3.
+*      If octlevel == 3, quantize to level 3 directly.
+*      For level 3, the quality is usually good enough and there
+*      is negligible chance of getting more than 256 colors.
+*  (2) For grayscale, multiply ncolors by 1.5 for extra quality,
+*      but use at least mingraycolors and not more than 256. */
+if (iscolor) {
+pixd = pixFewColorsOctcubeQuant1(pixs, octlevel);
+if (!pixd) {  /* backoff */
+pixd = pixFewColorsOctcubeQuant1(pixs, octlevel - 1);
+if (octlevel == 3)  /* shouldn't happen */
+L_WARNING("quantized at level 2; low quality\n", __func__);
+}
+} else { /* image is really grayscale */
+if (d == 32)
+pixg = pixConvertRGBToLuminance(pixs);
+else
+pixg = pixClone(pixs);
+graycolors = L_MAX(mingraycolors, (l_int32)(1.5 * ncolors));
+graycolors = L_MIN(graycolors, 256);
+if (graycolors < 16)
+pixd = pixThresholdTo4bpp(pixg, graycolors, 1);
+else
+pixd = pixThresholdOn8bpp(pixg, graycolors, 1);
+pixDestroy(&pixg);
+}
+*ppixd = pixd;
+if (!pixd)
+return ERROR_INT("pixd not made", __func__, 1);
+pixCopyInputFormat(pixd, pixs);
+return 0;
+}
+/*---------------------------------------------------------------------------*
+*                    Conversion from 16 bpp to 8 bpp                        *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert16To8()
+*
+* \param[in]    pixs     16 bpp
+* \param[in]    type     L_LS_BYTE, L_MS_BYTE, L_AUTO_BYTE, L_CLIP_TO_FF
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) With L_AUTO_BYTE, if the max pixel value is greater than 255,
+*          use the MSB; otherwise, use the LSB.
+*      (2) With L_CLIP_TO_FF, use min(pixel-value, 0xff) for each
+*          16-bit src pixel.
+* </pre>
+*/
+PIX *
+pixConvert16To8(PIX     *pixs,
+l_int32  type)
+{
+l_uint16   dword;
+l_int32    w, h, wpls, wpld, i, j, val, use_lsb;
+l_uint32   sword, first, second;
+l_uint32  *datas, *datad, *lines, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 16)
+return (PIX *)ERROR_PTR("pixs not 16 bpp", __func__, NULL);
+if (type != L_LS_BYTE && type != L_MS_BYTE &&
+type != L_AUTO_BYTE && type != L_CLIP_TO_FF)
+return (PIX *)ERROR_PTR("invalid type", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyInputFormat(pixd, pixs);
+pixCopyResolution(pixd, pixs);
+wpls = pixGetWpl(pixs);
+datas = pixGetData(pixs);
+wpld = pixGetWpl(pixd);
+datad = pixGetData(pixd);
+if (type == L_AUTO_BYTE) {
+use_lsb = TRUE;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+for (j = 0; j < wpls; j++) {
+val = GET_DATA_TWO_BYTES(lines, j);
+if (val > 255) {
+use_lsb = FALSE;
+break;
+}
+}
+if (!use_lsb) break;
+}
+type = (use_lsb) ? L_LS_BYTE : L_MS_BYTE;
+}
+/* Convert 2 pixels at a time */
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+if (type == L_LS_BYTE) {
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+dword = ((sword >> 8) & 0xff00) | (sword & 0xff);
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+} else if (type == L_MS_BYTE) {
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+dword = ((sword >> 16) & 0xff00) | ((sword >> 8) & 0xff);
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+} else {  /* type == L_CLIP_TO_FF */
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+first = (sword >> 24) ? 255 : ((sword >> 16) & 0xff);
+second = ((sword >> 8) & 0xff) ? 255 : (sword & 0xff);
+dword = (first << 8) | second;
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+}
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                Conversion from grayscale to false color
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertGrayToFalseColor()
+*
+* \param[in]    pixs    8 or 16 bpp grayscale
+* \param[in]    gamma   (factor) 0.0 or 1.0 for default; > 1.0 for brighter;
+*                       2.0 is quite nice
+* \return  pixd 8 bpp with colormap, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) For 8 bpp input, this simply adds a colormap to the input image.
+*      (2) For 16 bpp input, it first converts to 8 bpp, using the MSB,
+*          and then adds the colormap.
+*      (3) The colormap is modeled after the Matlab "jet" configuration.
+* </pre>
+*/
+PIX *
+pixConvertGrayToFalseColor(PIX       *pixs,
+l_float32  gamma)
+{
+l_int32   d;
+PIX      *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 8 && d != 16)
+return (PIX *)ERROR_PTR("pixs not 8 or 16 bpp", __func__, NULL);
+if (d == 16) {
+pixd = pixConvert16To8(pixs, L_MS_BYTE);
+} else {  /* d == 8 */
+if (pixGetColormap(pixs))
+pixd = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+else
+pixd = pixCopy(NULL, pixs);
+}
+if (!pixd)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+cmap = pixcmapGrayToFalseColor(gamma);
+pixSetColormap(pixd, cmap);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*         Unpacking conversion from 1 bpp to 2, 4, 8, 16 and 32 bpp         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixUnpackBinary()
+*
+* \param[in]    pixs     1 bpp
+* \param[in]    depth    of destination: 2, 4, 8, 16 or 32 bpp
+* \param[in]    invert   0:  binary 0 --> grayscale 0
+*                            binary 1 --> grayscale 0xff...
+*                        1:  binary 0 --> grayscale 0xff...
+*                            binary 1 --> grayscale 0
+* \return  pixd 2, 4, 8, 16 or 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This function calls special cases of pixConvert1To*(),
+*          for 2, 4, 8, 16 and 32 bpp destinations.
+* </pre>
+*/
+PIX *
+pixUnpackBinary(PIX     *pixs,
+l_int32  depth,
+l_int32  invert)
+{
+PIX  *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+if (depth != 2 && depth != 4 && depth != 8 && depth != 16 && depth != 32)
+return (PIX *)ERROR_PTR("depth not 2, 4, 8, 16 or 32 bpp",
+__func__, NULL);
+if (depth == 2) {
+if (invert == 0)
+pixd = pixConvert1To2(NULL, pixs, 0, 3);
+else  /* invert bits */
+pixd = pixConvert1To2(NULL, pixs, 3, 0);
+} else if (depth == 4) {
+if (invert == 0)
+pixd = pixConvert1To4(NULL, pixs, 0, 15);
+else  /* invert bits */
+pixd = pixConvert1To4(NULL, pixs, 15, 0);
+} else if (depth == 8) {
+if (invert == 0)
+pixd = pixConvert1To8(NULL, pixs, 0, 255);
+else  /* invert bits */
+pixd = pixConvert1To8(NULL, pixs, 255, 0);
+} else if (depth == 16) {
+if (invert == 0)
+pixd = pixConvert1To16(NULL, pixs, 0, 0xffff);
+else  /* invert bits */
+pixd = pixConvert1To16(NULL, pixs, 0xffff, 0);
+} else {
+if (invert == 0)
+pixd = pixConvert1To32(NULL, pixs, 0, 0xffffffff);
+else  /* invert bits */
+pixd = pixConvert1To32(NULL, pixs, 0xffffffff, 0);
+}
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvert1To16()
+*
+* \param[in]    pixd    [optional] 16 bpp, can be null
+* \param[in]    pixs    1 bpp
+* \param[in]    val0    16 bit value to be used for 0s in pixs
+* \param[in]    val1    16 bit value to be used for 1s in pixs
+* \return  pixd 16 bpp
+*
+* <pre>
+* Notes:
+*      (1) If pixd is null, a new pix is made.
+*      (2) If pixd is not null, it must be of equal width and height
+*          as pixs.  It is always returned.
+* </pre>
+*/
+PIX *
+pixConvert1To16(PIX      *pixd,
+PIX      *pixs,
+l_uint16  val0,
+l_uint16  val1)
+{
+l_int32    w, h, i, j, dibit, ndibits, wpls, wpld;
+l_uint16   val[2];
+l_uint32   index;
+l_uint32  *tab, *datas, *datad, *lines, *lined;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+if (pixd) {
+if (w != pixGetWidth(pixd) || h != pixGetHeight(pixd))
+return (PIX *)ERROR_PTR("pix sizes unequal", __func__, pixd);
+if (pixGetDepth(pixd) != 16)
+return (PIX *)ERROR_PTR("pixd not 16 bpp", __func__, pixd);
+} else {
+if ((pixd = pixCreate(w, h, 16)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+/* Use a table to convert 2 src bits at a time */
+tab = (l_uint32 *)LEPT_CALLOC(4, sizeof(l_uint32));
+val[0] = val0;
+val[1] = val1;
+for (index = 0; index < 4; index++) {
+tab[index] = (val[(index >> 1) & 1] << 16) | val[index & 1];
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+ndibits = (w + 1) / 2;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < ndibits; j++) {
+dibit = GET_DATA_DIBIT(lines, j);
+lined[j] = tab[dibit];
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*!
+* \brief   pixConvert1To32()
+*
+* \param[in]    pixd    [optional] 32 bpp, can be null
+* \param[in]    pixs    1 bpp
+* \param[in]    val0    32 bit value to be used for 0s in pixs
+* \param[in]    val1    32 bit value to be used for 1s in pixs
+* \return  pixd 32 bpp
+*
+* <pre>
+* Notes:
+*      (1) If pixd is null, a new pix is made.
+*      (2) If pixd is not null, it must be of equal width and height
+*          as pixs.  It is always returned.
+* </pre>
+*/
+PIX *
+pixConvert1To32(PIX      *pixd,
+PIX      *pixs,
+l_uint32  val0,
+l_uint32  val1)
+{
+l_int32    w, h, i, j, wpls, wpld, bit;
+l_uint32   val[2];
+l_uint32  *datas, *datad, *lines, *lined;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+if (pixd) {
+if (w != pixGetWidth(pixd) || h != pixGetHeight(pixd))
+return (PIX *)ERROR_PTR("pix sizes unequal", __func__, pixd);
+if (pixGetDepth(pixd) != 32)
+return (PIX *)ERROR_PTR("pixd not 32 bpp", __func__, pixd);
+} else {
+if ((pixd = pixCreate(w, h, 32)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+val[0] = val0;
+val[1] = val1;
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j <w; j++) {
+bit = GET_DATA_BIT(lines, j);
+lined[j] = val[bit];
+}
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                    Conversion from 1 bpp to 2 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert1To2Cmap()
+*
+* \param[in]    pixs    1 bpp
+* \return  pixd 2 bpp, cmapped
+*
+* <pre>
+* Notes:
+*      (1) Input 0 is mapped to (255, 255, 255); 1 is mapped to (0, 0, 0)
+* </pre>
+*/
+PIX *
+pixConvert1To2Cmap(PIX  *pixs)
+{
+PIX      *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+if ((pixd = pixConvert1To2(NULL, pixs, 0, 1)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+cmap = pixcmapCreate(2);
+pixcmapAddColor(cmap, 255, 255, 255);
+pixcmapAddColor(cmap, 0, 0, 0);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvert1To2()
+*
+* \param[in]    pixd    [optional] 2 bpp, can be null
+* \param[in]    pixs    1 bpp
+* \param[in]    val0    2 bit value to be used for 0s in pixs
+* \param[in]    val1    2 bit value to be used for 1s in pixs
+* \return  pixd 2 bpp
+*
+* <pre>
+* Notes:
+*      (1) If pixd is null, a new pix is made.
+*      (2) If pixd is not null, it must be of equal width and height
+*          as pixs.  It is always returned.
+*      (3) A simple unpacking might use val0 = 0 and val1 = 3.
+*      (4) If you want a colormapped pixd, use pixConvert1To2Cmap().
+* </pre>
+*/
+PIX *
+pixConvert1To2(PIX     *pixd,
+PIX     *pixs,
+l_int32  val0,
+l_int32  val1)
+{
+l_int32    w, h, i, j, byteval, nbytes, wpls, wpld;
+l_uint8    val[2];
+l_uint32   index;
+l_uint16  *tab;
+l_uint32  *datas, *datad, *lines, *lined;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, pixd);
+pixGetDimensions(pixs, &w, &h, NULL);
+if (pixd) {
+if (w != pixGetWidth(pixd) || h != pixGetHeight(pixd))
+return (PIX *)ERROR_PTR("pix sizes unequal", __func__, pixd);
+if (pixGetDepth(pixd) != 2)
+return (PIX *)ERROR_PTR("pixd not 2 bpp", __func__, pixd);
+} else {
+if ((pixd = pixCreate(w, h, 2)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+/* Use a table to convert 8 src bits to 16 dest bits */
+tab = (l_uint16 *)LEPT_CALLOC(256, sizeof(l_uint16));
+val[0] = val0;
+val[1] = val1;
+for (index = 0; index < 256; index++) {
+tab[index] = (val[(index >> 7) & 1] << 14) |
+(val[(index >> 6) & 1] << 12) |
+(val[(index >> 5) & 1] << 10) |
+(val[(index >> 4) & 1] << 8) |
+(val[(index >> 3) & 1] << 6) |
+(val[(index >> 2) & 1] << 4) |
+(val[(index >> 1) & 1] << 2) | val[index & 1];
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+nbytes = (w + 7) / 8;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < nbytes; j++) {
+byteval = GET_DATA_BYTE(lines, j);
+SET_DATA_TWO_BYTES(lined, j, tab[byteval]);
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                    Conversion from 1 bpp to 4 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert1To4Cmap()
+*
+* \param[in]    pixs    1 bpp
+* \return  pixd 4 bpp, cmapped
+*
+* <pre>
+* Notes:
+*      (1) Input 0 is mapped to (255, 255, 255); 1 is mapped to (0, 0, 0)
+* </pre>
+*/
+PIX *
+pixConvert1To4Cmap(PIX  *pixs)
+{
+PIX      *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+if ((pixd = pixConvert1To4(NULL, pixs, 0, 1)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+cmap = pixcmapCreate(4);
+pixcmapAddColor(cmap, 255, 255, 255);
+pixcmapAddColor(cmap, 0, 0, 0);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvert1To4()
+*
+* \param[in]    pixd    [optional] 4 bpp, can be null
+* \param[in]    pixs    1 bpp
+* \param[in]    val0    4 bit value to be used for 0s in pixs
+* \param[in]    val1    4 bit value to be used for 1s in pixs
+* \return  pixd 4 bpp
+*
+* <pre>
+* Notes:
+*      (1) If pixd is null, a new pix is made.
+*      (2) If pixd is not null, it must be of equal width and height
+*          as pixs.  It is always returned.
+*      (3) A simple unpacking might use val0 = 0 and val1 = 15, or v.v.
+*      (4) If you want a colormapped pixd, use pixConvert1To4Cmap().
+* </pre>
+*/
+PIX *
+pixConvert1To4(PIX     *pixd,
+PIX     *pixs,
+l_int32  val0,
+l_int32  val1)
+{
+l_int32    w, h, i, j, byteval, nbytes, wpls, wpld;
+l_uint8    val[2];
+l_uint32   index;
+l_uint32  *tab, *datas, *datad, *lines, *lined;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, pixd);
+pixGetDimensions(pixs, &w, &h, NULL);
+if (pixd) {
+if (w != pixGetWidth(pixd) || h != pixGetHeight(pixd))
+return (PIX *)ERROR_PTR("pix sizes unequal", __func__, pixd);
+if (pixGetDepth(pixd) != 4)
+return (PIX *)ERROR_PTR("pixd not 4 bpp", __func__, pixd);
+} else {
+if ((pixd = pixCreate(w, h, 4)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+/* Use a table to convert 8 src bits to 32 bit dest word */
+tab = (l_uint32 *)LEPT_CALLOC(256, sizeof(l_uint32));
+val[0] = val0;
+val[1] = val1;
+for (index = 0; index < 256; index++) {
+tab[index] = (val[(index >> 7) & 1] << 28) |
+(val[(index >> 6) & 1] << 24) |
+(val[(index >> 5) & 1] << 20) |
+(val[(index >> 4) & 1] << 16) |
+(val[(index >> 3) & 1] << 12) |
+(val[(index >> 2) & 1] << 8) |
+(val[(index >> 1) & 1] << 4) | val[index & 1];
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+nbytes = (w + 7) / 8;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < nbytes; j++) {
+byteval = GET_DATA_BYTE(lines, j);
+lined[j] = tab[byteval];
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*               Conversion from 1, 2 and 4 bpp to 8 bpp                     *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert1To8Cmap()
+*
+* \param[in]    pixs    1 bpp
+* \return  pixd 8 bpp, cmapped
+*
+* <pre>
+* Notes:
+*      (1) Input 0 is mapped to (255, 255, 255); 1 is mapped to (0, 0, 0)
+* </pre>
+*/
+PIX *
+pixConvert1To8Cmap(PIX  *pixs)
+{
+PIX      *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, NULL);
+if ((pixd = pixConvert1To8(NULL, pixs, 0, 1)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+cmap = pixcmapCreate(8);
+pixcmapAddColor(cmap, 255, 255, 255);
+pixcmapAddColor(cmap, 0, 0, 0);
+pixSetColormap(pixd, cmap);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvert1To8()
+*
+* \param[in]    pixd    [optional] 8 bpp, can be null
+* \param[in]    pixs    1 bpp
+* \param[in]    val0    8 bit value to be used for 0s in pixs
+* \param[in]    val1    8 bit value to be used for 1s in pixs
+* \return  pixd 8 bpp
+*
+* <pre>
+* Notes:
+*      (1) If pixd is null, a new pix is made.
+*      (2) If pixd is not null, it must be of equal width and height
+*          as pixs.  It is always returned.
+*      (3) A simple unpacking might use val0 = 0 and val1 = 255, or v.v.
+*      (4) To have a colormap associated with the 8 bpp pixd,
+*          use pixConvert1To8Cmap().
+* </pre>
+*/
+PIX *
+pixConvert1To8(PIX     *pixd,
+PIX     *pixs,
+l_uint8  val0,
+l_uint8  val1)
+{
+l_int32    w, h, i, j, qbit, nqbits, wpls, wpld;
+l_uint8    val[2];
+l_uint32   index;
+l_uint32  *tab, *datas, *datad, *lines, *lined;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd);
+if (pixGetDepth(pixs) != 1)
+return (PIX *)ERROR_PTR("pixs not 1 bpp", __func__, pixd);
+pixGetDimensions(pixs, &w, &h, NULL);
+if (pixd) {
+if (w != pixGetWidth(pixd) || h != pixGetHeight(pixd))
+return (PIX *)ERROR_PTR("pix sizes unequal", __func__, pixd);
+if (pixGetDepth(pixd) != 8)
+return (PIX *)ERROR_PTR("pixd not 8 bpp", __func__, pixd);
+} else {
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+pixSetPadBits(pixs, 0);
+/* Use a table to convert 4 src bits at a time */
+tab = (l_uint32 *)LEPT_CALLOC(16, sizeof(l_uint32));
+val[0] = val0;
+val[1] = val1;
+for (index = 0; index < 16; index++) {
+tab[index] = ((l_uint32)val[(index >> 3) & 1] << 24) |
+(val[(index >> 2) & 1] << 16) |
+(val[(index >> 1) & 1] << 8) | val[index & 1];
+}
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+nqbits = (w + 3) / 4;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < nqbits; j++) {
+qbit = GET_DATA_QBIT(lines, j);
+lined[j] = tab[qbit];
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*!
+* \brief   pixConvert2To8()
+*
+* \param[in]    pixs      2 bpp
+* \param[in]    val0      8 bit value to be used for 00 in pixs
+* \param[in]    val1      8 bit value to be used for 01 in pixs
+* \param[in]    val2      8 bit value to be used for 10 in pixs
+* \param[in]    val3      8 bit value to be used for 11 in pixs
+* \param[in]    cmapflag  TRUE if pixd is to have a colormap; FALSE otherwise
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      ~ A simple unpacking might use val0 = 0,
+*        val1 = 85 (0x55), val2 = 170 (0xaa), val3 = 255.
+*      ~ If cmapflag is TRUE:
+*          ~ The 8 bpp image is made with a colormap.
+*          ~ If pixs has a colormap, the input values are ignored and
+*            the 8 bpp image is made using the colormap
+*          ~ If pixs does not have a colormap, the input values are
+*            used to build the colormap.
+*      ~ If cmapflag is FALSE:
+*          ~ The 8 bpp image is made without a colormap.
+*          ~ If pixs has a colormap, the input values are ignored,
+*            the colormap is removed, and the values stored in the 8 bpp
+*            image are from the colormap.
+*          ~ If pixs does not have a colormap, the input values are
+*            used to populate the 8 bpp image.
+* </pre>
+*/
+PIX *
+pixConvert2To8(PIX     *pixs,
+l_uint8  val0,
+l_uint8  val1,
+l_uint8  val2,
+l_uint8  val3,
+l_int32  cmapflag)
+{
+l_int32    w, h, i, j, nbytes, wpls, wpld, dibit, byte;
+l_uint32   val[4];
+l_uint32   index;
+l_uint32  *tab, *datas, *datad, *lines, *lined;
+PIX       *pixd;
+PIXCMAP   *cmaps, *cmapd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 2)
+return (PIX *)ERROR_PTR("pixs not 2 bpp", __func__, NULL);
+cmaps = pixGetColormap(pixs);
+if (cmaps && cmapflag == FALSE)
+return pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+pixGetDimensions(pixs, &w, &h, NULL);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixSetPadBits(pixs, 0);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+if (cmapflag == TRUE) {  /* pixd will have a colormap */
+if (cmaps) {  /* use the existing colormap from pixs */
+cmapd = pixcmapConvertTo8(cmaps);
+} else {  /* make a colormap from the input values */
+cmapd = pixcmapCreate(8);
+pixcmapAddColor(cmapd, val0, val0, val0);
+pixcmapAddColor(cmapd, val1, val1, val1);
+pixcmapAddColor(cmapd, val2, val2, val2);
+pixcmapAddColor(cmapd, val3, val3, val3);
+}
+pixSetColormap(pixd, cmapd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+dibit = GET_DATA_DIBIT(lines, j);
+SET_DATA_BYTE(lined, j, dibit);
+}
+}
+return pixd;
+}
+/* Last case: no colormap in either pixs or pixd.
+* Use input values and build a table to convert 1 src byte
+* (4 src pixels) at a time */
+tab = (l_uint32 *)LEPT_CALLOC(256, sizeof(l_uint32));
+val[0] = val0;
+val[1] = val1;
+val[2] = val2;
+val[3] = val3;
+for (index = 0; index < 256; index++) {
+tab[index] = (val[(index >> 6) & 3] << 24) |
+(val[(index >> 4) & 3] << 16) |
+(val[(index >> 2) & 3] << 8) | val[index & 3];
+}
+nbytes = (w + 3) / 4;
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < nbytes; j++) {
+byte = GET_DATA_BYTE(lines, j);
+lined[j] = tab[byte];
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*!
+* \brief   pixConvert4To8()
+*
+* \param[in]    pixs      4 bpp
+* \param[in]    cmapflag  TRUE if pixd is to have a colormap; FALSE otherwise
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      ~ If cmapflag is TRUE:
+*          ~ pixd is made with a colormap.
+*          ~ If pixs has a colormap, it is copied and the colormap
+*            index values are placed in pixd.
+*          ~ If pixs does not have a colormap, a colormap with linear
+*            trc is built and the pixel values in pixs are placed in
+*            pixd as colormap index values.
+*      ~ If cmapflag is FALSE:
+*          ~ pixd is made without a colormap.
+*          ~ If pixs has a colormap, it is removed and the values stored
+*            in pixd are from the colormap (converted to gray).
+*          ~ If pixs does not have a colormap, the pixel values in pixs
+*            are used, with shift replication, to populate pixd.
+* </pre>
+*/
+PIX *
+pixConvert4To8(PIX     *pixs,
+l_int32  cmapflag)
+{
+l_int32    w, h, i, j, wpls, wpld, byte, qbit;
+l_uint32  *datas, *datad, *lines, *lined;
+PIX       *pixd;
+PIXCMAP   *cmaps, *cmapd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 4)
+return (PIX *)ERROR_PTR("pixs not 4 bpp", __func__, NULL);
+cmaps = pixGetColormap(pixs);
+if (cmaps && cmapflag == FALSE)
+return pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+pixGetDimensions(pixs, &w, &h, NULL);
+if ((pixd = pixCreate(w, h, 8)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+if (cmapflag == TRUE) {  /* pixd will have a colormap */
+if (cmaps) {  /* use the existing colormap from pixs */
+cmapd = pixcmapConvertTo8(cmaps);
+} else {  /* make a colormap with a linear trc */
+cmapd = pixcmapCreate(8);
+for (i = 0; i < 16; i++)
+pixcmapAddColor(cmapd, 17 * i, 17 * i, 17 * i);
+}
+pixSetColormap(pixd, cmapd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+qbit = GET_DATA_QBIT(lines, j);
+SET_DATA_BYTE(lined, j, qbit);
+}
+}
+return pixd;
+}
+/* Last case: no colormap in either pixs or pixd.
+* Replicate the qbit value into 8 bits. */
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+qbit = GET_DATA_QBIT(lines, j);
+byte = (qbit << 4) | qbit;
+SET_DATA_BYTE(lined, j, byte);
+}
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*               Unpacking conversion from 8 bpp to 16 bpp                   *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert8To16()
+*
+* \param[in]    pixs       8 bpp; colormap removed to gray
+* \param[in]    leftshift  number of bits: 0 is no shift;
+*                          8 replicates in MSB and LSB of dest
+* \return  pixd 16 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) For left shift of 8, the 8 bit value is replicated in both
+*          the MSB and the LSB of the pixels in pixd.  That way, we get
+*          proportional mapping, with a correct map from 8 bpp white
+*          (0xff) to 16 bpp white (0xffff).
+* </pre>
+*/
+PIX *
+pixConvert8To16(PIX     *pixs,
+l_int32  leftshift)
+{
+l_int32    i, j, w, h, d, wplt, wpld, val;
+l_uint32  *datat, *datad, *linet, *lined;
+PIX       *pixt, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, &d);
+if (d != 8)
+return (PIX *)ERROR_PTR("pixs not 8 bpp", __func__, NULL);
+if (leftshift < 0 || leftshift > 8)
+return (PIX *)ERROR_PTR("leftshift not in [0 ... 8]", __func__, NULL);
+if (pixGetColormap(pixs) != NULL)
+pixt = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+else
+pixt = pixClone(pixs);
+pixd = pixCreate(w, h, 16);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datat = pixGetData(pixt);
+datad = pixGetData(pixd);
+wplt = pixGetWpl(pixt);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+linet = datat + i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(linet, j);
+if (leftshift == 8)
+val = val | (val << leftshift);
+else
+val <<= leftshift;
+SET_DATA_TWO_BYTES(lined, j, val);
+}
+}
+pixDestroy(&pixt);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                     Top-level conversion to 2 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo2()
+*
+* \param[in]    pixs   1, 2, 4, 8, 24, 32 bpp; colormap OK but will be removed
+* \return  pixd   2 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, with simple default values
+*          used in pixConvertTo8() if unpacking is necessary.
+*      (2) Any existing colormap is removed; the result is always gray.
+*      (3) If the input image has 2 bpp and no colormap, the operation is
+*          lossless and a copy is returned.
+* </pre>
+*/
+PIX *
+pixConvertTo2(PIX  *pixs)
+{
+l_int32  d;
+PIX     *pix1, *pix2, *pix3, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 24 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,24,32}", __func__, NULL);
+if (pixGetColormap(pixs) != NULL) {
+pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+d = pixGetDepth(pix1);
+} else {
+pix1 = pixCopy(NULL, pixs);
+}
+if (d == 24 || d == 32)
+pix2 = pixConvertTo8(pix1, FALSE);
+else
+pix2 = pixClone(pix1);
+pixDestroy(&pix1);
+if (d == 1) {
+pixd = pixConvert1To2(NULL, pix2, 3, 0);
+} else if (d == 2) {
+pixd = pixClone(pix2);
+} else if (d == 4) {
+pix3 = pixConvert4To8(pix2, FALSE);  /* unpack to 8 */
+pixd = pixConvert8To2(pix3);
+pixDestroy(&pix3);
+} else {  /* d == 8 */
+pixd = pixConvert8To2(pix2);
+}
+pixDestroy(&pix2);
+return pixd;
+}
+/*!
+* \brief   pixConvert8To2()
+*
+* \param[in]     pix     8 bpp; colormap OK
+* \return  pixd  2 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Any existing colormap is removed to gray.
+* </pre>
+*/
+PIX *
+pixConvert8To2(PIX  *pix)
+{
+l_int32    i, j, w, h, wpls, wpld;
+l_uint32   word;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixs, *pixd;
+if (!pix || pixGetDepth(pix) != 8)
+return (PIX *)ERROR_PTR("pix undefined or not 8 bpp", __func__, NULL);
+if (pixGetColormap(pix) != NULL)
+pixs = pixRemoveColormap(pix, REMOVE_CMAP_TO_GRAYSCALE);
+else
+pixs = pixClone(pix);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+pixd = pixCreate(w, h, 2);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < wpls; j++) {  /* march through 4 pixels at a time */
+word = lines[j] & 0xc0c0c0c0;  /* top 2 bits of each byte */
+word = (word >> 24) | ((word & 0xff0000) >> 18) |
+((word & 0xff00) >> 12) | ((word & 0xff) >> 6);
+SET_DATA_BYTE(lined, j, word);  /* only LS byte is filled */
+}
+}
+pixDestroy(&pixs);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                     Top-level conversion to 4 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo4()
+*
+* \param[in]    pixs   1, 2, 4, 8, 24, 32 bpp; colormap OK but will be removed
+* \return  pixd   4 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, with simple default values
+*          used in pixConvertTo8() if unpacking is necessary.
+*      (2) Any existing colormap is removed; the result is always gray.
+*      (3) If the input image has 4 bpp and no colormap, the operation is
+*          lossless and a copy is returned.
+* </pre>
+*/
+PIX *
+pixConvertTo4(PIX  *pixs)
+{
+l_int32  d;
+PIX     *pix1, *pix2, *pix3, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 24 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,24,32}", __func__, NULL);
+if (pixGetColormap(pixs) != NULL) {
+pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+d = pixGetDepth(pix1);
+} else {
+pix1 = pixCopy(NULL, pixs);
+}
+if (d == 24 || d == 32)
+pix2 = pixConvertTo8(pix1, FALSE);
+else
+pix2 = pixClone(pix1);
+pixDestroy(&pix1);
+if (d == 1) {
+pixd = pixConvert1To4(NULL, pix2, 15, 0);
+} else if (d == 2) {
+pix3 = pixConvert2To8(pix2, 0, 0x55, 0xaa, 0xff, FALSE);
+pixd = pixConvert8To4(pix3);
+pixDestroy(&pix3);
+} else if (d == 4) {
+pixd = pixClone(pix2);
+} else {  /* d == 8 */
+pixd = pixConvert8To4(pix2);
+}
+pixDestroy(&pix2);
+return pixd;
+}
+/*!
+* \brief   pixConvert8To4()
+*
+* \param[in]     pix     8 bpp; colormap OK
+* \return  pixd  4 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) Any existing colormap is removed to gray.
+* </pre>
+*/
+PIX *
+pixConvert8To4(PIX  *pix)
+{
+l_int32    i, j, w, h, wpls, wpld, val;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixs, *pixd;
+if (!pix || pixGetDepth(pix) != 8)
+return (PIX *)ERROR_PTR("pix undefined or not 8 bpp", __func__, NULL);
+if (pixGetColormap(pix) != NULL)
+pixs = pixRemoveColormap(pix, REMOVE_CMAP_TO_GRAYSCALE);
+else
+pixs = pixClone(pix);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+pixd = pixCreate(w, h, 4);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(lines, j);
+val = val >> 4;  /* take top 4 bits */
+SET_DATA_QBIT(lined, j, val);
+}
+}
+pixDestroy(&pixs);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                     Top-level conversion to 1 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo1Adaptive()
+*
+* \param[in]    pixs       1, 2, 4, 8, 16, 24 or 32 bpp
+* \return  pixd 1 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, that uses default values for
+*          adaptive thresholding, if necessary.  Otherwise, it is the same as
+*          pixConvertTo1(), which uses a global threshold for binarization.
+*      (2) Other high-level adaptive thresholding functions are
+*          pixAdaptThresholdToBinary() and pixCleanImage().
+* </pre>
+*/
+PIX *
+pixConvertTo1Adaptive(PIX     *pixs)
+{
+l_int32   d, color0, color1, rval, gval, bval;
+PIX      *pix1, *pix2, *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 16 && d != 24 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,16,24,32}", __func__, NULL);
+cmap = pixGetColormap(pixs);
+if (d == 1) {
+if (!cmap) {
+return pixCopy(NULL, pixs);
+} else {  /* strip the colormap off, and invert if reasonable
+for standard binary photometry.  */
+pixcmapGetColor(cmap, 0, &rval, &gval, &bval);
+color0 = rval + gval + bval;
+pixcmapGetColor(cmap, 1, &rval, &gval, &bval);
+color1 = rval + gval + bval;
+pixd = pixCopy(NULL, pixs);
+pixDestroyColormap(pixd);
+if (color1 > color0)
+pixInvert(pixd, pixd);
+return pixd;
+}
+}
+/* For all other depths, use 8 bpp as an intermediary */
+pix1 = pixConvertTo8(pixs, FALSE);
+pix2 = pixBackgroundNormSimple(pix1, NULL, NULL);
+pixd = pixThresholdToBinary(pix2, 180);
+pixDestroy(&pix1);
+pixDestroy(&pix2);
+return pixd;
+}
+/*!
+* \brief   pixConvertTo1()
+*
+* \param[in]    pixs       1, 2, 4, 8, 16, 24 or 32 bpp
+* \param[in]    threshold  for final binarization, relative to 8 bpp
+* \return  pixd 1 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, with simple default values
+*          used in pixConvertTo8() if unpacking is necessary.
+*      (2) Any existing colormap is removed.
+*      (3) If the input image has 1 bpp and no colormap, the operation is
+*          lossless and a copy is returned.
+* </pre>
+*/
+PIX *
+pixConvertTo1(PIX     *pixs,
+l_int32  threshold)
+{
+l_int32   d, color0, color1, rval, gval, bval;
+PIX      *pixg, *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 16 && d != 24 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,16,24,32}", __func__, NULL);
+cmap = pixGetColormap(pixs);
+if (d == 1) {
+if (!cmap) {
+return pixCopy(NULL, pixs);
+} else {  /* strip the colormap off, and invert if reasonable
+for standard binary photometry.  */
+pixcmapGetColor(cmap, 0, &rval, &gval, &bval);
+color0 = rval + gval + bval;
+pixcmapGetColor(cmap, 1, &rval, &gval, &bval);
+color1 = rval + gval + bval;
+pixd = pixCopy(NULL, pixs);
+pixDestroyColormap(pixd);
+if (color1 > color0)
+pixInvert(pixd, pixd);
+return pixd;
+}
+}
+/* For all other depths, use 8 bpp as an intermediary */
+pixg = pixConvertTo8(pixs, FALSE);
+pixd = pixThresholdToBinary(pixg, threshold);
+pixDestroy(&pixg);
+return pixd;
+}
+/*!
+* \brief   pixConvertTo1BySampling()
+*
+* \param[in]    pixs       1, 2, 4, 8, 16, 24 or 32 bpp
+* \param[in]    factor     subsampling factor; integer >= 1
+* \param[in]    threshold  for final binarization, relative to 8 bpp
+* \return  pixd 1 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a quick and dirty, top-level converter.
+*      (2) See pixConvertTo1() for default values.
+* </pre>
+*/
+PIX *
+pixConvertTo1BySampling(PIX     *pixs,
+l_int32  factor,
+l_int32  threshold)
+{
+l_float32  scalefactor;
+PIX       *pixt, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (factor < 1)
+return (PIX *)ERROR_PTR("factor must be >= 1", __func__, NULL);
+scalefactor = 1.f / (l_float32)factor;
+pixt = pixScaleBySampling(pixs, scalefactor, scalefactor);
+pixd = pixConvertTo1(pixt, threshold);
+pixDestroy(&pixt);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                     Top-level conversion to 8 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo8()
+*
+* \param[in]    pixs      1, 2, 4, 8, 16, 24 or 32 bpp
+* \param[in]    cmapflag  TRUE if pixd is to have a colormap; FALSE otherwise
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, with simple default values
+*          for unpacking.
+*      (2) The result, pixd, is made with a colormap if specified.
+*          It is always a new image -- never a clone.  For example,
+*          if d == 8, and cmapflag matches the existence of a cmap
+*          in pixs, the operation is lossless and it returns a copy.
+*      (3) The default values used are:
+*          ~ 1 bpp: val0 = 255, val1 = 0
+*          ~ 2 bpp: 4 bpp:  even increments over dynamic range
+*          ~ 8 bpp: lossless if cmap matches cmapflag
+*          ~ 16 bpp: use most significant byte
+*      (4) If 24 bpp or 32 bpp RGB, this is converted to gray.
+*          For color quantization, you must specify the type explicitly,
+*          using the color quantization code.
+* </pre>
+*/
+PIX *
+pixConvertTo8(PIX     *pixs,
+l_int32  cmapflag)
+{
+l_int32   d;
+PIX      *pix1, *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 16 && d != 24 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,16,24,32}", __func__, NULL);
+if (d == 1) {
+if (cmapflag)
+return pixConvert1To8Cmap(pixs);
+else
+return pixConvert1To8(NULL, pixs, 255, 0);
+} else if (d == 2) {
+return pixConvert2To8(pixs, 0, 85, 170, 255, cmapflag);
+} else if (d == 4) {
+return pixConvert4To8(pixs, cmapflag);
+} else if (d == 8) {
+cmap = pixGetColormap(pixs);
+if ((cmap && cmapflag) || (!cmap && !cmapflag)) {
+return pixCopy(NULL, pixs);
+} else if (cmap) {  /* !cmapflag */
+return pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+} else {  /* !cmap && cmapflag; add colormap to pixd */
+pixd = pixCopy(NULL, pixs);
+pixAddGrayColormap8(pixd);
+return pixd;
+}
+} else if (d == 16) {
+pixd = pixConvert16To8(pixs, L_MS_BYTE);
+if (cmapflag)
+pixAddGrayColormap8(pixd);
+return pixd;
+} else if (d == 24) {
+pix1 = pixConvert24To32(pixs);
+pixd = pixConvertRGBToLuminance(pix1);
+if (cmapflag)
+pixAddGrayColormap8(pixd);
+pixDestroy(&pix1);
+return pixd;
+} else { /* d == 32 */
+pixd = pixConvertRGBToLuminance(pixs);
+if (cmapflag)
+pixAddGrayColormap8(pixd);
+return pixd;
+}
+}
+/*!
+* \brief   pixConvertTo8BySampling()
+*
+* \param[in]    pixs      1, 2, 4, 8, 16 or 32 bpp
+* \param[in]    factor    submsampling factor; integer >= 1
+* \param[in]    cmapflag  TRUE if pixd is to have a colormap; FALSE otherwise
+* \return  pixd 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a fast, quick/dirty, top-level converter.
+*      (2) See pixConvertTo8() for default values.
+* </pre>
+*/
+PIX *
+pixConvertTo8BySampling(PIX     *pixs,
+l_int32  factor,
+l_int32  cmapflag)
+{
+l_float32  scalefactor;
+PIX       *pixt, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (factor < 1)
+return (PIX *)ERROR_PTR("factor must be >= 1", __func__, NULL);
+scalefactor = 1.f / (l_float32)factor;
+pixt = pixScaleBySampling(pixs, scalefactor, scalefactor);
+pixd = pixConvertTo8(pixt, cmapflag);
+pixDestroy(&pixt);
+return pixd;
+}
+/*!
+* \brief   pixConvertTo8Colormap()
+*
+* \param[in]    pixs    1, 2, 4, 8, 16 or 32 bpp
+* \param[in]    dither  1 to dither if necessary; 0 otherwise
+* \return  pixd 8 bpp, cmapped, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a top-level function, with simple default values
+*          for unpacking.
+*      (2) The result, pixd, is always made with a colormap.
+*      (3) If d == 8, the operation is lossless and it returns a copy.
+*      (4) The default values used for increasing depth are:
+*          ~ 1 bpp: val0 = 255, val1 = 0
+*          ~ 2 bpp: 4 bpp:  even increments over dynamic range
+*      (5) For 16 bpp, use the most significant byte.
+*      (6) For 32 bpp RGB, use octcube quantization with optional dithering.
+* </pre>
+*/
+PIX *
+pixConvertTo8Colormap(PIX     *pixs,
+l_int32  dither)
+{
+l_int32  d;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d != 1 && d != 2 && d != 4 && d != 8 && d != 16 && d != 32)
+return (PIX *)ERROR_PTR("depth not {1,2,4,8,16,32}", __func__, NULL);
+if (d != 32)
+return pixConvertTo8(pixs, 1);
+return pixConvertRGBToColormap(pixs, dither);
+}
+/*---------------------------------------------------------------------------*
+*                    Top-level conversion to 16 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo16()
+*
+* \param[in]    pixs    1, 8 bpp
+* \return  pixd 16 bpp, or NULL on error
+*
+*  Usage: Top-level function, with simple default values for unpacking.
+*      1 bpp:  val0 = 0xffff, val1 = 0
+*      8 bpp:  replicates the 8 bit value in both the MSB and LSB
+*              of the 16 bit pixel.
+*/
+PIX *
+pixConvertTo16(PIX  *pixs)
+{
+l_int32  d;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d == 1)
+return pixConvert1To16(NULL, pixs, 0xffff, 0);
+else if (d == 8)
+return pixConvert8To16(pixs, 8);
+else
+return (PIX *)ERROR_PTR("src depth not 1 or 8 bpp", __func__, NULL);
+}
+/*---------------------------------------------------------------------------*
+*                    Top-level conversion to 32 bpp                         *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo32()
+*
+* \param[in]    pixs    1, 2, 4, 8, 16, 24 or 32 bpp
+* \return  pixd 32 bpp, or NULL on error
+*
+*  Usage: Top-level function, with simple default values for unpacking.
+*      1 bpp:  val0 = 255, val1 = 0
+*              and then replication into R, G and B components
+*      2 bpp:  if colormapped, use the colormap values; otherwise,
+*              use val0 = 0, val1 = 0x55, val2 = 0xaa, val3 = 255
+*              and replicate gray into R, G and B components
+*      4 bpp:  if colormapped, use the colormap values; otherwise,
+*              replicate 2 nybs into a byte, and then into R,G,B components
+*      8 bpp:  if colormapped, use the colormap values; otherwise,
+*              replicate gray values into R, G and B components
+*      16 bpp: replicate MSB into R, G and B components
+*      24 bpp: unpack the pixels, maintaining word alignment on each scanline
+*      32 bpp: makes a copy
+*
+* <pre>
+* Notes:
+*      (1) Never returns a clone of pixs.
+* </pre>
+*/
+PIX *
+pixConvertTo32(PIX  *pixs)
+{
+l_int32  d;
+PIX     *pix1, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+if (d == 1) {
+return pixConvert1To32(NULL, pixs, 0xffffffff, 0);
+} else if (d == 2) {
+pix1 = pixConvert2To8(pixs, 0, 85, 170, 255, TRUE);
+pixd = pixConvert8To32(pix1);
+pixDestroy(&pix1);
+return pixd;
+} else if (d == 4) {
+pix1 = pixConvert4To8(pixs, TRUE);
+pixd = pixConvert8To32(pix1);
+pixDestroy(&pix1);
+return pixd;
+} else if (d == 8) {
+return pixConvert8To32(pixs);
+} else if (d == 16) {
+pix1 = pixConvert16To8(pixs, L_MS_BYTE);
+pixd = pixConvert8To32(pix1);
+pixDestroy(&pix1);
+return pixd;
+} else if (d == 24) {
+return pixConvert24To32(pixs);
+} else if (d == 32) {
+return pixCopy(NULL, pixs);
+} else {
+return (PIX *)ERROR_PTR("depth not 1, 2, 4, 8, 16, 32 bpp",
+__func__, NULL);
+}
+}
+/*!
+* \brief   pixConvertTo32BySampling()
+*
+* \param[in]    pixs    1, 2, 4, 8, 16, 24 or 32 bpp
+* \param[in]    factor  submsampling factor; integer >= 1
+* \return  pixd 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a fast, quick/dirty, top-level converter.
+*      (2) See pixConvertTo32() for default values.
+* </pre>
+*/
+PIX *
+pixConvertTo32BySampling(PIX     *pixs,
+l_int32  factor)
+{
+l_float32  scalefactor;
+PIX       *pix1, *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (factor < 1)
+return (PIX *)ERROR_PTR("factor must be >= 1", __func__, NULL);
+scalefactor = 1.f / (l_float32)factor;
+pix1 = pixScaleBySampling(pixs, scalefactor, scalefactor);
+pixd = pixConvertTo32(pix1);
+pixDestroy(&pix1);
+return pixd;
+}
+/*!
+* \brief   pixConvert8To32()
+*
+* \param[in]    pixs    8 bpp
+* \return  32 bpp rgb pix, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If there is no colormap, replicates the gray value
+*          into the 3 MSB of the dest pixel.
+* </pre>
+*/
+PIX *
+pixConvert8To32(PIX  *pixs)
+{
+l_int32    i, j, w, h, wpls, wpld, val;
+l_uint32  *datas, *datad, *lines, *lined;
+l_uint32  *tab;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) != 8)
+return (PIX *)ERROR_PTR("pixs not 8 bpp", __func__, NULL);
+if (pixGetColormap(pixs))
+return pixRemoveColormap(pixs, REMOVE_CMAP_TO_FULL_COLOR);
+pixGetDimensions(pixs, &w, &h, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+if ((pixd = pixCreate(w, h, 32)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+/* Replication table gray --> rgb */
+tab = (l_uint32 *)LEPT_CALLOC(256, sizeof(l_uint32));
+for (i = 0; i < 256; i++)
+tab[i] = ((l_uint32)i << 24) | (i << 16) | (i << 8);
+/* Replicate 1 --> 4 bytes (alpha byte not set) */
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+val = GET_DATA_BYTE(lines, j);
+lined[j] = tab[val];
+}
+}
+LEPT_FREE(tab);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*           Top-level conversion to 8 or 32 bpp, without colormap           *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertTo8Or32()
+*
+* \param[in]    pixs      1, 2, 4, 8, 16, with or without colormap;
+*                         or 32 bpp rgb
+* \param[in]    copyflag  L_CLONE or L_COPY
+* \param[in]    warnflag  1 to issue warning if colormap is removed; else 0
+* \return  pixd 8 bpp grayscale or 32 bpp rgb, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If there is a colormap, the colormap is removed to 8 or 32 bpp,
+*          depending on whether the colors in the colormap are all gray.
+*      (2) If the input is either rgb or 8 bpp without a colormap,
+*          this returns either a clone or a copy, depending on %copyflag.
+*      (3) Otherwise, the pix is converted to 8 bpp grayscale.
+*          In all cases, pixd does not have a colormap.
+* </pre>
+*/
+PIX *
+pixConvertTo8Or32(PIX     *pixs,
+l_int32  copyflag,
+l_int32  warnflag)
+{
+l_int32  d;
+PIX     *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (copyflag != L_CLONE && copyflag != L_COPY)
+return (PIX *)ERROR_PTR("invalid copyflag", __func__, NULL);
+d = pixGetDepth(pixs);
+if (pixGetColormap(pixs)) {
+if (warnflag) L_WARNING("pix has colormap; removing\n", __func__);
+pixd = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
+} else if (d == 8 || d == 32) {
+if (copyflag == L_CLONE)
+pixd = pixClone(pixs);
+else  /* copyflag == L_COPY */
+pixd = pixCopy(NULL, pixs);
+} else {
+pixd = pixConvertTo8(pixs, 0);
+}
+/* Sanity check on result */
+d = pixGetDepth(pixd);
+if (d != 8 && d != 32) {
+pixDestroy(&pixd);
+return (PIX *)ERROR_PTR("depth not 8 or 32 bpp", __func__, NULL);
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                 Conversion between 24 bpp and 32 bpp rgb                  *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert24To32()
+*
+* \param[in]    pixs    24 bpp rgb
+* \return  pixd 32 bpp rgb, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) 24 bpp rgb pix are not supported in leptonica, except for a small
+*          number of formatted write operations.  The data is a byte array,
+*          with pixels in order r,g,b, and padded to 32 bit boundaries
+*          in each line.
+*      (2) Because 24 bpp rgb pix are conveniently generated by programs
+*          such as xpdf (which has SplashBitmaps that store the raster
+*          data in consecutive 24-bit rgb pixels), it is useful to provide
+*          24 bpp pix that simply incorporate that data.  The only things
+*          we can do with these are:
+*            (a) write them to file in png, jpeg, tiff and pnm
+*            (b) interconvert between 24 and 32 bpp in memory (for testing).
+* </pre>
+*/
+PIX *
+pixConvert24To32(PIX  *pixs)
+{
+l_uint8   *lines;
+l_int32    w, h, d, i, j, wpls, wpld, rval, gval, bval;
+l_uint32   pixel;
+l_uint32  *datas, *datad, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, &d);
+if (d != 24)
+return (PIX *)ERROR_PTR("pixs not 24 bpp", __func__, NULL);
+pixd = pixCreate(w, h, 32);
+datas = pixGetData(pixs);
+datad = pixGetData(pixd);
+wpls = pixGetWpl(pixs);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = (l_uint8 *)(datas + i * wpls);
+lined = datad + i * wpld;
+for (j = 0; j < w; j++) {
+rval = *lines++;
+gval = *lines++;
+bval = *lines++;
+composeRGBPixel(rval, gval, bval, &pixel);
+lined[j] = pixel;
+}
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*!
+* \brief   pixConvert32To24()
+*
+* \param[in]    pixs    32 bpp rgb
+* \return  pixd 24 bpp rgb, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) See pixconvert24To32().
+* </pre>
+*/
+PIX *
+pixConvert32To24(PIX  *pixs)
+{
+l_uint8   *rgbdata8;
+l_int32    w, h, d, i, j, wpls, wpld, rval, gval, bval;
+l_uint32  *datas, *lines, *rgbdata;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, &d);
+if (d != 32)
+return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL);
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+pixd = pixCreate(w, h, 24);
+rgbdata = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+rgbdata8 = (l_uint8 *)(rgbdata + i * wpld);
+for (j = 0; j < w; j++) {
+extractRGBValues(lines[j], &rval, &gval, &bval);
+*rgbdata8++ = rval;
+*rgbdata8++ = gval;
+*rgbdata8++ = bval;
+}
+}
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*            Conversion between 32 bpp (1 spp) and 16 or 8 bpp              *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvert32To16()
+*
+* \param[in]    pixs   32 bpp, single component
+* \param[in]    type   L_LS_TWO_BYTES, L_MS_TWO_BYTES, L_CLIP_TO_FFFF
+* \return  pixd 16 bpp , or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) The data in pixs is typically used for labelling.
+*          It is an array of l_uint32 values, not rgb or rgba.
+* </pre>
+*/
+PIX *
+pixConvert32To16(PIX     *pixs,
+l_int32  type)
+{
+l_uint16   dword;
+l_int32    w, h, i, j, wpls, wpld;
+l_uint32   sword;
+l_uint32  *datas, *lines, *datad, *lined;
+PIX       *pixd;
+if (!pixs || pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, NULL);
+if (type != L_LS_TWO_BYTES && type != L_MS_TWO_BYTES &&
+type != L_CLIP_TO_FFFF)
+return (PIX *)ERROR_PTR("invalid type", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, NULL);
+if ((pixd = pixCreate(w, h, 16)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+wpls = pixGetWpl(pixs);
+datas = pixGetData(pixs);
+wpld = pixGetWpl(pixd);
+datad = pixGetData(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+if (type == L_LS_TWO_BYTES) {
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+dword = sword & 0xffff;
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+} else if (type == L_MS_TWO_BYTES) {
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+dword = sword >> 16;
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+} else {  /* type == L_CLIP_TO_FFFF */
+for (j = 0; j < wpls; j++) {
+sword = *(lines + j);
+dword = (sword >> 16) ? 0xffff : (sword & 0xffff);
+SET_DATA_TWO_BYTES(lined, j, dword);
+}
+}
+}
+return pixd;
+}
+/*!
+* \brief   pixConvert32To8()
+*
+* \param[in]    pixs    32 bpp, single component
+* \param[in]    type16  L_LS_TWO_BYTES, L_MS_TWO_BYTES, L_CLIP_TO_FFFF
+* \param[in]    type8   L_LS_BYTE, L_MS_BYTE, L_CLIP_TO_FF
+* \return  pixd 8 bpp, or NULL on error
+*/
+PIX *
+pixConvert32To8(PIX     *pixs,
+l_int32  type16,
+l_int32  type8)
+{
+PIX  *pix1, *pixd;
+if (!pixs || pixGetDepth(pixs) != 32)
+return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, NULL);
+if (type16 != L_LS_TWO_BYTES && type16 != L_MS_TWO_BYTES &&
+type16 != L_CLIP_TO_FFFF)
+return (PIX *)ERROR_PTR("invalid type16", __func__, NULL);
+if (type8 != L_LS_BYTE && type8 != L_MS_BYTE && type8 != L_CLIP_TO_FF)
+return (PIX *)ERROR_PTR("invalid type8", __func__, NULL);
+pix1 = pixConvert32To16(pixs, type16);
+pixd = pixConvert16To8(pix1, type8);
+pixDestroy(&pix1);
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*        Removal of alpha component by blending with white background       *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixRemoveAlpha()
+*
+* \param[in]    pixs   any depth
+* \return  pixd        if 32 bpp rgba, pixs blended over a white background;
+*                      a clone of pixs otherwise, and NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a wrapper on pixAlphaBlendUniform()
+* </pre>
+*/
+PIX *
+pixRemoveAlpha(PIX *pixs)
+{
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetDepth(pixs) == 32 && pixGetSpp(pixs) == 4)
+return pixAlphaBlendUniform(pixs, 0xffffff00);
+else
+return pixClone(pixs);
+}
+/*---------------------------------------------------------------------------*
+*                  Addition of alpha component to 1 bpp                     *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixAddAlphaTo1bpp()
+*
+* \param[in]    pixd    [optional] 1 bpp, can be null or equal to pixs
+* \param[in]    pixs    1 bpp
+* \return  pixd 1 bpp with colormap and non-opaque alpha,
+*                    or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) We don't use 1 bpp colormapped images with alpha in leptonica,
+*          but we support generating them (here), writing to png, and reading
+*          the png.  On reading, they are converted to 32 bpp RGBA.
+*      (2) The background (0) pixels in pixs become fully transparent, and the
+*          foreground (1) pixels are fully opaque.  Thus, pixd is a 1 bpp
+*          representation of a stencil, that can be used to paint over pixels
+*          of a backing image that are masked by the foreground in pixs.
+* </pre>
+*/
+PIX *
+pixAddAlphaTo1bpp(PIX  *pixd,
+PIX  *pixs)
+{
+PIXCMAP  *cmap;
+if (!pixs || (pixGetDepth(pixs) != 1))
+return (PIX *)ERROR_PTR("pixs undefined or not 1 bpp", __func__, NULL);
+if (pixd && (pixd != pixs))
+return (PIX *)ERROR_PTR("pixd defined but != pixs", __func__, NULL);
+pixd = pixCopy(pixd, pixs);
+cmap = pixcmapCreate(1);
+pixSetColormap(pixd, cmap);
+pixcmapAddRGBA(cmap, 255, 255, 255, 0);  /* 0 ==> white + transparent */
+pixcmapAddRGBA(cmap, 0, 0, 0, 255);  /* 1 ==> black + opaque */
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                  Lossless depth conversion (unpacking)                    *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertLossless()
+*
+* \param[in]    pixs    1, 2, 4, 8 bpp, not cmapped
+* \param[in]    d       destination depth: 2, 4 or 8
+* \return  pixd 2, 4 or 8 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) This is a lossless unpacking (depth-increasing)
+*          conversion.  If ds is the depth of pixs, then
+*           ~ if d < ds, returns NULL
+*           ~ if d == ds, returns a copy
+*           ~ if d > ds, does the unpacking conversion
+*      (2) If pixs has a colormap, this is an error.
+* </pre>
+*/
+PIX *
+pixConvertLossless(PIX     *pixs,
+l_int32  d)
+{
+l_int32    w, h, ds, wpls, wpld, i, j, val;
+l_uint32  *datas, *datad, *lines, *lined;
+PIX       *pixd;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+if (pixGetColormap(pixs))
+return (PIX *)ERROR_PTR("pixs has colormap", __func__, NULL);
+if (d != 2 && d != 4 && d != 8)
+return (PIX *)ERROR_PTR("invalid dest depth", __func__, NULL);
+pixGetDimensions(pixs, &w, &h, &ds);
+if (d < ds)
+return (PIX *)ERROR_PTR("depth > d", __func__, NULL);
+else if (d == ds)
+return pixCopy(NULL, pixs);
+if ((pixd = pixCreate(w, h, d)) == NULL)
+return (PIX *)ERROR_PTR("pixd not made", __func__, NULL);
+pixCopyResolution(pixd, pixs);
+pixCopyInputFormat(pixd, pixs);
+/* Unpack the bits */
+datas = pixGetData(pixs);
+wpls = pixGetWpl(pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+for (i = 0; i < h; i++) {
+lines = datas + i * wpls;
+lined = datad + i * wpld;
+switch (ds)
+{
+case 1:
+for (j = 0; j < w; j++) {
+val = GET_DATA_BIT(lines, j);
+if (d == 8)
+SET_DATA_BYTE(lined, j, val);
+else if (d == 4)
+SET_DATA_QBIT(lined, j, val);
+else  /* d == 2 */
+SET_DATA_DIBIT(lined, j, val);
+}
+break;
+case 2:
+for (j = 0; j < w; j++) {
+val = GET_DATA_DIBIT(lines, j);
+if (d == 8)
+SET_DATA_BYTE(lined, j, val);
+else  /* d == 4 */
+SET_DATA_QBIT(lined, j, val);
+}
+break;
+case 4:
+for (j = 0; j < w; j++) {
+val = GET_DATA_DIBIT(lines, j);
+SET_DATA_BYTE(lined, j, val);
+}
+break;
+}
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                     Conversion for printing in PostScript                 *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertForPSWrap()
+*
+* \param[in]    pixs    1, 2, 4, 8, 16, 32 bpp
+* \return  pixd    1, 8, or 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) For wrapping in PostScript, we convert pixs to
+*          1 bpp, 8 bpp (gray) and 32 bpp (RGB color).
+*      (2) Colormaps are removed.  For pixs with colormaps, the
+*          images are converted to either 8 bpp gray or 32 bpp
+*          RGB, depending on whether the colormap has color content.
+*      (3) Images without colormaps, that are not 1 bpp or 32 bpp,
+*          are converted to 8 bpp gray.
+* </pre>
+*/
+PIX *
+pixConvertForPSWrap(PIX  *pixs)
+{
+l_int32   d;
+PIX      *pixd;
+PIXCMAP  *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+cmap = pixGetColormap(pixs);
+d = pixGetDepth(pixs);
+switch (d)
+{
+case 1:
+case 32:
+pixd = pixClone(pixs);
+break;
+case 2:
+if (cmap)
+pixd = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
+else
+pixd = pixConvert2To8(pixs, 0, 0x55, 0xaa, 0xff, FALSE);
+break;
+case 4:
+if (cmap)
+pixd = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
+else
+pixd = pixConvert4To8(pixs, FALSE);
+break;
+case 8:
+pixd = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
+break;
+case 16:
+pixd = pixConvert16To8(pixs, L_MS_BYTE);
+break;
+default:
+lept_stderr("depth not in {1, 2, 4, 8, 16, 32}");
+return NULL;
+}
+return pixd;
+}
+/*---------------------------------------------------------------------------*
+*                      Scaling conversion to subpixel RGB                   *
+*---------------------------------------------------------------------------*/
+/*!
+* \brief   pixConvertToSubpixelRGB()
+*
+* \param[in]    pixs            8 bpp grayscale, 32 bpp rgb, or colormapped
+* \param[in]    scalex, scaley  anisotropic scaling permitted between
+*                               source and destination
+* \param[in]    order           of subpixel rgb color components in
+*                               composition of pixd:
+*                               L_SUBPIXEL_ORDER_RGB, L_SUBPIXEL_ORDER_BGR,
+*                               L_SUBPIXEL_ORDER_VRGB, L_SUBPIXEL_ORDER_VBGR
+* \return  pixd 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If pixs has a colormap, it is removed based on its contents
+*          to either 8 bpp gray or rgb.
+*      (2) For horizontal subpixel splitting, the input image
+*          is rescaled by %scaley vertically and by 3.0 times
+*          %scalex horizontally.  Then each horizontal triplet
+*          of pixels is mapped back to a single rgb pixel, with the
+*          r, g and b values being assigned based on the pixel triplet.
+*          For gray triplets, the r, g, and b values are set equal to
+*          the three gray values.  For color triplets, the r, g and b
+*          values are set equal to the components from the appropriate
+*          subpixel.  Vertical subpixel splitting is handled similarly.
+*      (3) See pixConvertGrayToSubpixelRGB() and
+*          pixConvertColorToSubpixelRGB() for further details.
+* </pre>
+*/
+PIX *
+pixConvertToSubpixelRGB(PIX       *pixs,
+l_float32  scalex,
+l_float32  scaley,
+l_int32    order)
+{
+l_int32    d;
+PIX       *pix1, *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+cmap = pixGetColormap(pixs);
+if (d != 8 && d != 32 && !cmap)
+return (PIX *)ERROR_PTR("pix not 8 or 32 bpp and not cmapped",
+__func__, NULL);
+if (scalex <= 0.0 || scaley <= 0.0)
+return (PIX *)ERROR_PTR("scale factors must be > 0", __func__, NULL);
+if (order != L_SUBPIXEL_ORDER_RGB && order != L_SUBPIXEL_ORDER_BGR &&
+order != L_SUBPIXEL_ORDER_VRGB && order != L_SUBPIXEL_ORDER_VBGR)
+return (PIX *)ERROR_PTR("invalid subpixel order", __func__, NULL);
+if ((pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC)) == NULL)
+return (PIX *)ERROR_PTR("pix1 not made", __func__, NULL);
+d = pixGetDepth(pix1);
+pixd = NULL;
+if (d == 8)
+pixd = pixConvertGrayToSubpixelRGB(pix1, scalex, scaley, order);
+else if (d == 32)
+pixd = pixConvertColorToSubpixelRGB(pix1, scalex, scaley, order);
+else
+L_ERROR("invalid depth %d\n", __func__, d);
+pixDestroy(&pix1);
+return pixd;
+}
+/*!
+* \brief   pixConvertGrayToSubpixelRGB()
+*
+* \param[in]    pixs            8 bpp or colormapped
+* \param[in]    scalex, scaley
+* \param[in]    order           of subpixel rgb color components in
+*                               composition of pixd:
+*                               L_SUBPIXEL_ORDER_RGB, L_SUBPIXEL_ORDER_BGR,
+*                               L_SUBPIXEL_ORDER_VRGB, L_SUBPIXEL_ORDER_VBGR
+* \return  pixd 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If pixs has a colormap, it is removed to 8 bpp.
+*      (2) For horizontal subpixel splitting, the input gray image
+*          is rescaled by %scaley vertically and by 3.0 times
+*          %scalex horizontally.  Then each horizontal triplet
+*          of pixels is mapped back to a single rgb pixel, with the
+*          r, g and b values being assigned from the triplet of gray values.
+*          Similar operations are used for vertical subpixel splitting.
+*      (3) This is a form of subpixel rendering that tends to give the
+*          resulting text a sharper and somewhat chromatic display.
+*          For horizontal subpixel splitting, the observable difference
+*          between %order=L_SUBPIXEL_ORDER_RGB and
+*          %order=L_SUBPIXEL_ORDER_BGR is reduced by optical diffusers
+*          in the display that make the pixel color appear to emerge
+*          from the entire pixel.
+* </pre>
+*/
+PIX *
+pixConvertGrayToSubpixelRGB(PIX       *pixs,
+l_float32  scalex,
+l_float32  scaley,
+l_int32    order)
+{
+l_int32    w, h, d, wd, hd, wplt, wpld, i, j, rval, gval, bval, direction;
+l_uint32  *datat, *datad, *linet, *lined;
+PIX       *pix1, *pix2, *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+cmap = pixGetColormap(pixs);
+if (d != 8 && !cmap)
+return (PIX *)ERROR_PTR("pix not 8 bpp & not cmapped", __func__, NULL);
+if (scalex <= 0.0 || scaley <= 0.0)
+return (PIX *)ERROR_PTR("scale factors must be > 0", __func__, NULL);
+if (order != L_SUBPIXEL_ORDER_RGB && order != L_SUBPIXEL_ORDER_BGR &&
+order != L_SUBPIXEL_ORDER_VRGB && order != L_SUBPIXEL_ORDER_VBGR)
+return (PIX *)ERROR_PTR("invalid subpixel order", __func__, NULL);
+direction =
+(order == L_SUBPIXEL_ORDER_RGB || order == L_SUBPIXEL_ORDER_BGR)
+? L_HORIZ : L_VERT;
+pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_TO_GRAYSCALE);
+if (direction == L_HORIZ)
+pix2 = pixScale(pix1, 3.0f * scalex, scaley);
+else  /* L_VERT */
+pix2 = pixScale(pix1, scalex, 3.0f * scaley);
+pixGetDimensions(pix2, &w, &h, NULL);
+wd = (direction == L_HORIZ) ? w / 3 : w;
+hd = (direction == L_VERT) ? h / 3 : h;
+pixd = pixCreate(wd, hd, 32);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+datat = pixGetData(pix2);
+wplt = pixGetWpl(pix2);
+if (direction == L_HORIZ) {
+for (i = 0; i < hd; i++) {
+linet = datat + i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < wd; j++) {
+rval = GET_DATA_BYTE(linet, 3 * j);
+gval = GET_DATA_BYTE(linet, 3 * j + 1);
+bval = GET_DATA_BYTE(linet, 3 * j + 2);
+if (order == L_SUBPIXEL_ORDER_RGB)
+composeRGBPixel(rval, gval, bval, &lined[j]);
+else  /* order BGR */
+composeRGBPixel(bval, gval, rval, &lined[j]);
+}
+}
+} else {  /* L_VERT */
+for (i = 0; i < hd; i++) {
+linet = datat + 3 * i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < wd; j++) {
+rval = GET_DATA_BYTE(linet, j);
+gval = GET_DATA_BYTE(linet + wplt, j);
+bval = GET_DATA_BYTE(linet + 2 * wplt, j);
+if (order == L_SUBPIXEL_ORDER_VRGB)
+composeRGBPixel(rval, gval, bval, &lined[j]);
+else  /* order VBGR */
+composeRGBPixel(bval, gval, rval, &lined[j]);
+}
+}
+}
+pixDestroy(&pix1);
+pixDestroy(&pix2);
+return pixd;
+}
+/*!
+* \brief   pixConvertColorToSubpixelRGB()
+*
+* \param[in]    pixs            32 bpp or colormapped
+* \param[in]    scalex, scaley
+* \param[in]    order           of subpixel rgb color components in
+*                               composition of pixd:
+*                               L_SUBPIXEL_ORDER_RGB, L_SUBPIXEL_ORDER_BGR,
+*                               L_SUBPIXEL_ORDER_VRGB, L_SUBPIXEL_ORDER_VBGR
+* \return  pixd 32 bpp, or NULL on error
+*
+* <pre>
+* Notes:
+*      (1) If pixs has a colormap, it is removed to 32 bpp rgb.
+*          If the colormap has no color, pixConvertGrayToSubpixelRGB()
+*          should be called instead, because it will give the same result
+*          more efficiently.  The function pixConvertToSubpixelRGB()
+*          will do the best thing for all cases.
+*      (2) For horizontal subpixel splitting, the input rgb image
+*          is rescaled by %scaley vertically and by 3.0 times
+*          %scalex horizontally.  Then for each horizontal triplet
+*          of pixels, the r component of the final pixel is selected
+*          from the r component of the appropriate pixel in the triplet,
+*          and likewise for g and b.  Vertical subpixel splitting is
+*          handled similarly.
+* </pre>
+*/
+PIX *
+pixConvertColorToSubpixelRGB(PIX       *pixs,
+l_float32  scalex,
+l_float32  scaley,
+l_int32    order)
+{
+l_int32    w, h, d, wd, hd, wplt, wpld, i, j, rval, gval, bval, direction;
+l_uint32  *datat, *datad, *linet, *lined;
+PIX       *pix1, *pix2, *pixd;
+PIXCMAP   *cmap;
+if (!pixs)
+return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL);
+d = pixGetDepth(pixs);
+cmap = pixGetColormap(pixs);
+if (d != 32 && !cmap)
+return (PIX *)ERROR_PTR("pix not 32 bpp & not cmapped", __func__, NULL);
+if (scalex <= 0.0 || scaley <= 0.0)
+return (PIX *)ERROR_PTR("scale factors must be > 0", __func__, NULL);
+if (order != L_SUBPIXEL_ORDER_RGB && order != L_SUBPIXEL_ORDER_BGR &&
+order != L_SUBPIXEL_ORDER_VRGB && order != L_SUBPIXEL_ORDER_VBGR)
+return (PIX *)ERROR_PTR("invalid subpixel order", __func__, NULL);
+direction =
+(order == L_SUBPIXEL_ORDER_RGB || order == L_SUBPIXEL_ORDER_BGR)
+? L_HORIZ : L_VERT;
+pix1 = pixRemoveColormap(pixs, REMOVE_CMAP_TO_FULL_COLOR);
+if (direction == L_HORIZ)
+pix2 = pixScale(pix1, 3.0f * scalex, scaley);
+else  /* L_VERT */
+pix2 = pixScale(pix1, scalex, 3.0f * scaley);
+pixGetDimensions(pix2, &w, &h, NULL);
+wd = (direction == L_HORIZ) ? w / 3 : w;
+hd = (direction == L_VERT) ? h / 3 : h;
+pixd = pixCreate(wd, hd, 32);
+pixCopyInputFormat(pixd, pixs);
+datad = pixGetData(pixd);
+wpld = pixGetWpl(pixd);
+datat = pixGetData(pix2);
+wplt = pixGetWpl(pix2);
+if (direction == L_HORIZ) {
+for (i = 0; i < hd; i++) {
+linet = datat + i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < wd; j++) {
+if (order == L_SUBPIXEL_ORDER_RGB) {
+extractRGBValues(linet[3 * j], &rval, NULL, NULL);
+extractRGBValues(linet[3 * j + 1], NULL, &gval, NULL);
+extractRGBValues(linet[3 * j + 2], NULL, NULL, &bval);
+} else {  /* order BGR */
+extractRGBValues(linet[3 * j], NULL, NULL, &bval);
+extractRGBValues(linet[3 * j + 1], NULL, &gval, NULL);
+extractRGBValues(linet[3 * j + 2], &rval, NULL, NULL);
+}
+composeRGBPixel(rval, gval, bval, &lined[j]);
+}
+}
+} else {  /* L_VERT */
+for (i = 0; i < hd; i++) {
+linet = datat + 3 * i * wplt;
+lined = datad + i * wpld;
+for (j = 0; j < wd; j++) {
+if (order == L_SUBPIXEL_ORDER_VRGB) {
+extractRGBValues(linet[j], &rval, NULL, NULL);
+extractRGBValues((linet + wplt)[j], NULL, &gval, NULL);
+extractRGBValues((linet + 2 * wplt)[j], NULL, NULL, &bval);
+} else {  /* order VBGR */
+extractRGBValues(linet[j], NULL, NULL, &bval);
+extractRGBValues((linet + wplt)[j], NULL, &gval, NULL);
+extractRGBValues((linet + 2 * wplt)[j], &rval, NULL, NULL);
+}
+composeRGBPixel(rval, gval, bval, &lined[j]);
+}
+}
+}
+if (pixGetSpp(pixs) == 4)
+pixScaleAndTransferAlpha(pixd, pixs, scalex, scaley);
+pixDestroy(&pix1);
+pixDestroy(&pix2);
+return pixd;
+}
+/*---------------------------------------------------------------------*
+*       Setting neutral point for min/max boost conversion to gray    *
+*---------------------------------------------------------------------*/
+/*!
+* \brief   l_setNeutralBoostVal()
+*
+* \param[in]    val    between 1 and 255; typical value is 180
+* \return  void
+*
+* <pre>
+* Notes:
+*      (1) This raises or lowers the selected min or max RGB component value,
+*          depending on if that component is above or below this value.
+* </pre>
+*/
+void
+l_setNeutralBoostVal(l_int32  val)
+{
+if (val <= 0) {
+L_ERROR("invalid reference value for neutral boost\n", __func__);
+return;
+}
+var_NEUTRAL_BOOST_VAL = val;
+}

Mercurial > hgrepos > Python2 > PyMuPDF

comparison mupdf-source/thirdparty/leptonica/src/pixconv.c @ 2:b50eed0cc0ef upstream