--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/leptonica/src/bmpio.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,668 @@
+/*====================================================================*
+ -  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 bmpio.c
+ * <pre>
+ *
+ *      Read bmp
+ *           PIX          *pixReadStreamBmp()
+ *           PIX          *pixReadMemBmp()
+ *
+ *      Write bmp
+ *           l_int32       pixWriteStreamBmp()
+ *           l_int32       pixWriteMemBmp()
+ *
+ * </pre>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config_auto.h>
+#endif  /* HAVE_CONFIG_H */
+
+#include <string.h>
+#include "allheaders.h"
+#include "pix_internal.h"
+#include "bmp.h"
+
+/* --------------------------------------------*/
+#if  USE_BMPIO   /* defined in environ.h */
+/* --------------------------------------------*/
+
+    /* Here we're setting the pixel value 0 to white (255) and the
+     * value 1 to black (0).  This is the convention for grayscale, but
+     * the opposite of the convention for 1 bpp, where 0 is white
+     * and 1 is black.  Both colormap entries are opaque (alpha = 255) */
+RGBA_QUAD   bwmap[2] = { {255,255,255,255}, {0,0,0,255} };
+
+    /* Image dimension limits */
+static const l_int32  L_MAX_ALLOWED_WIDTH = 1000000;
+static const l_int32  L_MAX_ALLOWED_HEIGHT = 1000000;
+static const l_int64  L_MAX_ALLOWED_PIXELS = 400000000LL;
+static const l_int32  L_MAX_ALLOWED_RES = 10000000;  /* pixels/meter */
+
+#ifndef  NO_CONSOLE_IO
+#define  DEBUG     0
+#endif  /* ~NO_CONSOLE_IO */
+
+/*--------------------------------------------------------------*
+ *                              Read bmp                        *
+ *--------------------------------------------------------------*/
+/*!
+ * \brief   pixReadStreamBmp()
+ *
+ * \param[in]    fp file stream opened for read
+ * \return  pix, or NULL on error
+ *
+ * <pre>
+ * Notes:
+ *      (1) Here are references on the bmp file format:
+ *          http://en.wikipedia.org/wiki/BMP_file_format
+ *          http://www.fortunecity.com/skyscraper/windows/364/bmpffrmt.html
+ * </pre>
+ */
+PIX *
+pixReadStreamBmp(FILE  *fp)
+{
+l_uint8  *data;
+size_t    size;
+PIX      *pix;
+
+    if (!fp)
+        return (PIX *)ERROR_PTR("fp not defined", __func__, NULL);
+
+        /* Read data from file and decode into Y,U,V arrays */
+    rewind(fp);
+    if ((data = l_binaryReadStream(fp, &size)) == NULL)
+        return (PIX *)ERROR_PTR("data not read", __func__, NULL);
+
+    pix = pixReadMemBmp(data, size);
+    LEPT_FREE(data);
+    return pix;
+}
+
+
+/*!
+ * \brief   pixReadMemBmp()
+ *
+ * \param[in]    cdata    bmp data
+ * \param[in]    size     number of bytes of bmp-formatted data
+ * \return  pix, or NULL on error
+ *
+ * <pre>
+ * Notes:
+ *      (1) The BMP file is organized as follows:
+ *          * 14 byte fileheader
+ *          * Variable size infoheader: 40, 108 or 124 bytes.
+ *            We only use data in he first 40 bytes.
+ *          * Optional colormap, with size 4 * ncolors (in bytes)
+ *          * Image data
+ *      (2) 2 bpp bmp files are not valid in the original spec, but they
+ *          are valid in later versions.
+ *      (3) We support reading rgb files with bpp = 24 and rgba files
+ *          with 32 bpp.  For the latter, the transparency component of
+ *          the generated pix is saved; however, for rgba images with
+ *          non-opaque transparent components, png provides more flexibility.
+ * </pre>
+ */
+PIX *
+pixReadMemBmp(const l_uint8  *cdata,
+              size_t          size)
+{
+l_uint8    pel[4];
+l_uint8   *cmapBuf, *fdata, *data, *bmpih_b;
+l_int16    bftype, depth, d;
+l_int32    offset, width, height, height_neg, xres, yres, spp;
+l_int32    compression, imagebytes, fdatabytes, cmapbytes, ncolors, maxcolors;
+l_int32    fdatabpl, extrabytes, filebpp, pixWpl, pixBpl, i, j, k;
+l_uint32   ihbytes;
+l_uint32  *line, *pixdata, *pword;
+l_int64    npixels;
+BMP_FH    *bmpfh;
+BMP_IH    bmpih;
+PIX       *pix, *pix1;
+PIXCMAP   *cmap;
+
+    if (!cdata)
+        return (PIX *)ERROR_PTR("cdata not defined", __func__, NULL);
+    if (size < sizeof(BMP_FH) + sizeof(BMP_IH))
+        return (PIX *)ERROR_PTR("bmf size error", __func__, NULL);
+
+        /* Verify this is an uncompressed bmp */
+    bmpfh = (BMP_FH *)cdata;
+    bftype = bmpfh->bfType[0] + ((l_int32)bmpfh->bfType[1] << 8);
+    if (bftype != BMP_ID)
+        return (PIX *)ERROR_PTR("not bmf format", __func__, NULL);
+    memcpy(&bmpih, cdata + BMP_FHBYTES, BMP_IHBYTES);
+    compression = convertOnBigEnd32(bmpih.biCompression);
+    if (compression != 0)
+        return (PIX *)ERROR_PTR("cannot read compressed BMP files",
+                                __func__, NULL);
+
+        /* Find the offset from the beginning of the file to the image data */
+    offset = bmpfh->bfOffBits[0];
+    offset += (l_int32)bmpfh->bfOffBits[1] << 8;
+    offset += (l_int32)bmpfh->bfOffBits[2] << 16;
+    offset += (l_uint32)bmpfh->bfOffBits[3] << 24;
+
+        /* Read the remaining useful data in the infoheader.
+         * Note that the first 4 bytes give the infoheader size.
+         * The infoheader pointer on sparc64 is not 32-bit aligned. */
+    bmpih_b = (l_uint8 *)&bmpih;
+    ihbytes = bmpih_b[0] | ((l_int32)bmpih_b[1] << 8) |
+              ((l_int32)bmpih_b[2] << 16) | ((l_uint32)bmpih_b[3] << 24);
+    width = convertOnBigEnd32(bmpih.biWidth);
+    height = convertOnBigEnd32(bmpih.biHeight);
+    depth = convertOnBigEnd16(bmpih.biBitCount);
+    imagebytes = convertOnBigEnd32(bmpih.biSizeImage);
+    xres = convertOnBigEnd32(bmpih.biXPelsPerMeter);
+    yres = convertOnBigEnd32(bmpih.biYPelsPerMeter);
+
+        /* Some sanity checking.  We impose limits on the image
+         * dimensions, resolution and number of pixels.  We make sure the
+         * file is the correct size to hold the amount of uncompressed data
+         * that is specified in the header.  The number of colormap
+         * entries is checked: it can be either 0 (no cmap) or some
+         * number between 2 and 256.
+         * Note that the imagebytes for uncompressed images is either
+         * 0 or the size of the file data.  (The fact that it can
+         * be 0 is perhaps some legacy glitch). */
+    if (width < 1)
+        return (PIX *)ERROR_PTR("width < 1", __func__, NULL);
+    if (width > L_MAX_ALLOWED_WIDTH)
+        return (PIX *)ERROR_PTR("width too large", __func__, NULL);
+    if (height == 0 || height < -L_MAX_ALLOWED_HEIGHT ||
+        height > L_MAX_ALLOWED_HEIGHT)
+        return (PIX *)ERROR_PTR("invalid height", __func__, NULL);
+    if (xres < 0 || xres > L_MAX_ALLOWED_RES ||
+        yres < 0 || yres > L_MAX_ALLOWED_RES)
+        return (PIX *)ERROR_PTR("invalid resolution", __func__, NULL);
+    height_neg = 0;
+    if (height < 0) {
+        height_neg = 1;
+        height = -height;
+    }
+    if (ihbytes != 40 && ihbytes != 108 && ihbytes != 124) {
+        L_ERROR("invalid ihbytes = %d; not in {40, 108, 124}\n",
+                __func__, ihbytes);
+        return NULL;
+    }
+    npixels = 1LL * width * height;
+    if (npixels > L_MAX_ALLOWED_PIXELS)
+        return (PIX *)ERROR_PTR("npixels too large", __func__, NULL);
+    if (depth != 1 && depth != 2 && depth != 4 && depth != 8 &&
+        depth != 16 && depth != 24 && depth != 32) {
+        L_ERROR("invalid depth = %d; not in {1, 2, 4, 8, 16, 24, 32}\n",
+                __func__, depth);
+        return NULL;
+    }
+    fdatabpl = 4 * ((1LL * width * depth + 31)/32);
+    fdatabytes = fdatabpl * height;
+    if (imagebytes != 0 && imagebytes != fdatabytes) {
+        L_ERROR("invalid imagebytes = %d; not equal to fdatabytes = %d\n",
+                __func__, imagebytes, fdatabytes);
+        return NULL;
+    }
+
+        /* In the original spec, BITMAPINFOHEADER is 40 bytes.
+         * There have been a number of revisions, to capture more information.
+         * For example, the fifth version, BITMAPV5HEADER, adds 84 bytes
+         * of ICC color profiles.  We use the size of the infoheader
+         * to accommodate these newer formats.  Knowing the size of the
+         * infoheader gives more opportunity to sanity check input params. */
+    cmapbytes = offset - BMP_FHBYTES - ihbytes;
+    ncolors = cmapbytes / sizeof(RGBA_QUAD);
+    if (ncolors < 0 || ncolors == 1)
+        return (PIX *)ERROR_PTR("invalid: cmap size < 0 or 1", __func__, NULL);
+    if (ncolors > 0 && depth > 8)
+        return (PIX *)ERROR_PTR("can't have cmap for d > 8", __func__, NULL);
+    maxcolors = (depth <= 8) ? 1 << depth : 0;
+    if (ncolors > maxcolors) {
+        L_ERROR("cmap too large for depth %d: ncolors = %d > maxcolors = %d\n",
+                __func__, depth, ncolors, maxcolors);
+        return NULL;
+    }
+    if (size != 1LL * offset + 1LL * fdatabytes)
+        return (PIX *)ERROR_PTR("size incommensurate with image data",
+                                __func__,NULL);
+
+        /* Handle the colormap */
+    cmapBuf = NULL;
+    if (ncolors > 0) {
+        if ((cmapBuf = (l_uint8 *)LEPT_CALLOC(ncolors, sizeof(RGBA_QUAD)))
+                 == NULL)
+            return (PIX *)ERROR_PTR("cmapBuf alloc fail", __func__, NULL );
+
+            /* Read the colormap entry data from bmp. The RGBA_QUAD colormap
+             * entries are used for both bmp and leptonica colormaps. */
+        memcpy(cmapBuf, cdata + BMP_FHBYTES + ihbytes,
+               ncolors * sizeof(RGBA_QUAD));
+    }
+
+        /* Make a 32 bpp pix if file depth is 24 bpp */
+    d = (depth == 24) ? 32 : depth;
+    if ((pix = pixCreate(width, height, d)) == NULL) {
+        LEPT_FREE(cmapBuf);
+        return (PIX *)ERROR_PTR( "pix not made", __func__, NULL);
+    }
+    pixSetXRes(pix, (l_int32)((l_float32)xres / 39.37 + 0.5));  /* to ppi */
+    pixSetYRes(pix, (l_int32)((l_float32)yres / 39.37 + 0.5));  /* to ppi */
+    pixSetInputFormat(pix, IFF_BMP);
+    pixWpl = pixGetWpl(pix);
+    pixBpl = 4 * pixWpl;
+    if (depth <= 16)
+        spp = 1;
+    else if (depth == 24)
+        spp = 3;
+    else  /* depth == 32 */
+        spp = 4;
+    pixSetSpp(pix, spp);
+
+        /* Convert the bmp colormap to a pixcmap */
+    cmap = NULL;
+    if (ncolors > 0) {  /* import the colormap to the pix cmap */
+        cmap = pixcmapCreate(L_MIN(d, 8));
+        LEPT_FREE(cmap->array);  /* remove generated cmap array */
+        cmap->array  = (void *)cmapBuf;  /* and replace */
+        cmap->n = L_MIN(ncolors, 256);
+        for (i = 0; i < cmap->n; i++)   /* set all colors opaque */
+            pixcmapSetAlpha (cmap, i, 255);
+    }
+    if (pixSetColormap(pix, cmap)) {
+        pixDestroy(&pix);
+        return (PIX *)ERROR_PTR("invalid colormap", __func__, NULL);
+    }
+
+        /* Acquire the image data.  Image origin for bmp is at lower right. */
+    fdata = (l_uint8 *)cdata + offset;  /* start of the bmp image data */
+    pixdata = pixGetData(pix);
+    if (depth != 24 && depth != 32) {  /* typ. 1 or 8 bpp */
+        data = (l_uint8 *)pixdata + pixBpl * (height - 1);
+        for (i = 0; i < height; i++) {
+            memcpy(data, fdata, fdatabpl);
+            fdata += fdatabpl;
+            data -= pixBpl;
+        }
+    } else {  /*  24 or 32 bpp file; 32 bpp pix
+             *  Note: for rgb bmp files, pel[0] is blue, pel[1] is green,
+             *  and pel[2] is red.  This is opposite to the storage
+             *  in the pix, which puts the red pixel in the 0 byte,
+             *  the green in the 1 byte and the blue in the 2 byte.
+             *  Note also that all words are endian flipped after
+             *  assignment on L_LITTLE_ENDIAN platforms.
+             *
+             *  We can then make these assignments for little endians:
+             *      SET_DATA_BYTE(pword, 1, pel[0]);      blue
+             *      SET_DATA_BYTE(pword, 2, pel[1]);      green
+             *      SET_DATA_BYTE(pword, 3, pel[2]);      red
+             *  This looks like:
+             *          3  (R)     2  (G)        1  (B)        0
+             *      |-----------|------------|-----------|-----------|
+             *  and after byte flipping:
+             *           3          2  (B)     1  (G)        0  (R)
+             *      |-----------|------------|-----------|-----------|
+             *
+             *  For big endians we set:
+             *      SET_DATA_BYTE(pword, 2, pel[0]);      blue
+             *      SET_DATA_BYTE(pword, 1, pel[1]);      green
+             *      SET_DATA_BYTE(pword, 0, pel[2]);      red
+             *  This looks like:
+             *          0  (R)     1  (G)        2  (B)        3
+             *      |-----------|------------|-----------|-----------|
+             *  so in both cases we get the correct assignment in the PIX.
+             *
+             *  Can we do a platform-independent assignment?
+             *  Yes, set the bytes without using macros:
+             *      *((l_uint8 *)pword) = pel[2];           red
+             *      *((l_uint8 *)pword + 1) = pel[1];       green
+             *      *((l_uint8 *)pword + 2) = pel[0];       blue
+             *  For little endians, before flipping, this looks again like:
+             *          3  (R)     2  (G)        1  (B)        0
+             *      |-----------|------------|-----------|-----------|
+             *
+             *  For reading an spp == 4 file with a transparency component,
+             *  the code below shows where the alpha component is located
+             *  in each pixel.
+             */
+        filebpp = (depth == 24) ? 3 : 4;
+        extrabytes = fdatabpl - filebpp * width;
+        line = pixdata + pixWpl * (height - 1);
+        for (i = 0; i < height; i++) {
+            for (j = 0; j < width; j++) {
+                pword = line + j;
+                memcpy(&pel, fdata, filebpp);
+                fdata += filebpp;
+                *((l_uint8 *)pword + COLOR_RED) = pel[2];
+                *((l_uint8 *)pword + COLOR_GREEN) = pel[1];
+                *((l_uint8 *)pword + COLOR_BLUE) = pel[0];
+                    /* Set the alpha byte to opaque for rgb */
+                if (depth == 24)
+                    *((l_uint8 *)pword + L_ALPHA_CHANNEL) = 255;
+                else
+                    *((l_uint8 *)pword + L_ALPHA_CHANNEL) = pel[3];
+            }
+            if (extrabytes) {
+                for (k = 0; k < extrabytes; k++) {
+                    memcpy(&pel, fdata, 1);
+                    fdata++;
+                }
+            }
+            line -= pixWpl;
+        }
+    }
+
+    pixEndianByteSwap(pix);
+    if (height_neg)
+        pixFlipTB(pix, pix);
+
+        /* ----------------------------------------------
+         * We do not use 1 bpp pix with colormaps in leptonica.
+         * The colormap must be removed in such a way that the pixel
+         * values are not changed.  If the values are only black and
+         * white, return a 1 bpp image; if gray, return an 8 bpp pix;
+         * otherwise, return a 32 bpp rgb pix.
+         * ---------------------------------------------- */
+    if (depth == 1 && cmap) {
+        L_INFO("removing opaque cmap from 1 bpp\n", __func__);
+        pix1 = pixRemoveColormap(pix, REMOVE_CMAP_BASED_ON_SRC);
+        pixDestroy(&pix);
+        pix = pix1;  /* rename */
+    }
+
+    return pix;
+}
+
+
+/*--------------------------------------------------------------*
+ *                            Write bmp                         *
+ *--------------------------------------------------------------*/
+/*!
+ * \brief   pixWriteStreamBmp()
+ *
+ * \param[in]    fp     file stream
+ * \param[in]    pix    all depths
+ * \return  0 if OK, 1 on error
+ */
+l_ok
+pixWriteStreamBmp(FILE  *fp,
+                  PIX   *pix)
+{
+l_uint8  *data;
+size_t    size, nbytes;
+
+    if (!fp)
+        return ERROR_INT("stream not defined", __func__, 1);
+    if (!pix)
+        return ERROR_INT("pix not defined", __func__, 1);
+
+    pixWriteMemBmp(&data, &size, pix);
+    rewind(fp);
+    nbytes = fwrite(data, 1, size, fp);
+    free(data);
+    if (nbytes != size) {
+        L_ERROR("Truncation: nbytes = %zu, size = %zu\n",
+                __func__,  nbytes, size);
+        return ERROR_INT("Write error", __func__, 1);
+    }
+    return 0;
+}
+
+
+/*!
+ * \brief   pixWriteMemBmp()
+ *
+ * \param[out]   pfdata   data of bmp formatted image
+ * \param[out]   pfsize    size of returned data
+ * \param[in]    pixs      1, 2, 4, 8, 16, 32 bpp
+ * \return  0 if OK, 1 on error
+ *
+ * <pre>
+ * Notes:
+ *      (1) 2 bpp bmp files are not valid in the original spec, and are
+ *          written as 8 bpp.
+ *      (2) pix with depth <= 8 bpp are written with a colormap.
+ *          16 bpp gray and 32 bpp rgb pix are written without a colormap.
+ *      (3) The transparency component in an rgba (spp = 4) pix is written.
+ *      (4) The bmp colormap entries, RGBA_QUAD, are the same as
+ *          the ones used for colormaps in leptonica.  This allows
+ *          a simple memcpy for bmp output.
+ * </pre>
+ */
+l_ok
+pixWriteMemBmp(l_uint8  **pfdata,
+               size_t    *pfsize,
+               PIX       *pixs)
+{
+l_uint8     pel[4];
+l_uint8    *cta = NULL;     /* address of the bmp color table array */
+l_uint8    *fdata, *data, *fmdata;
+l_int32     cmaplen;      /* number of bytes in the bmp colormap */
+l_int32     ncolors, val, stepsize, w, h, d, fdepth, xres, yres, valid;
+l_int32     pixWpl, pixBpl, extrabytes, spp, fBpl, fWpl, i, j, k;
+l_int32     heapcm;  /* extra copy of cta on the heap ? 1 : 0 */
+l_uint32    offbytes, fimagebytes;
+l_uint32   *line, *pword;
+size_t      fsize;
+BMP_FH     *bmpfh;
+BMP_IH     bmpih;
+PIX        *pix;
+PIXCMAP    *cmap;
+RGBA_QUAD  *pquad;
+
+    if (pfdata) *pfdata = NULL;
+    if (pfsize) *pfsize = 0;
+    if (!pfdata)
+        return ERROR_INT("&fdata not defined", __func__, 1 );
+    if (!pfsize)
+        return ERROR_INT("&fsize not defined", __func__, 1 );
+    if (!pixs)
+        return ERROR_INT("pixs not defined", __func__, 1);
+
+        /* Verify validity of colormap */
+    if ((cmap = pixGetColormap(pixs)) != NULL) {
+        pixcmapIsValid(cmap, pixs, &valid);
+        if (!valid)
+            return ERROR_INT("colormap is not valid", __func__, 1);
+    }
+
+    pixGetDimensions(pixs, &w, &h, &d);
+    spp = pixGetSpp(pixs);
+    if (spp != 1 && spp != 3 && spp != 4) {
+        L_ERROR("unsupported spp = %d\n", __func__, spp);
+        return 1;
+    } 
+    if (d == 2) {
+        L_WARNING("2 bpp files can't be read; converting to 8 bpp\n",
+                  __func__);
+        pix = pixConvert2To8(pixs, 0, 85, 170, 255, 1);
+        d = 8;
+    } else if (d == 24) {
+        pix = pixConvert24To32(pixs);
+        d = 32;
+    } else {
+        pix = pixCopy(NULL, pixs);
+    }
+
+        /* Find the bits/pixel to be written to file */
+    if (spp == 1)
+        fdepth = d;
+    else if (spp == 3)
+        fdepth = 24;
+    else  /* spp == 4 */
+        fdepth = 32;
+
+        /* Resolution is given in pixels/meter */
+    xres = (l_int32)(39.37 * (l_float32)pixGetXRes(pix) + 0.5);
+    yres = (l_int32)(39.37 * (l_float32)pixGetYRes(pix) + 0.5);
+
+    pixWpl = pixGetWpl(pix);
+    pixBpl = 4 * pixWpl;
+    fWpl = (w * fdepth + 31) / 32;
+    fBpl = 4 * fWpl;
+    fimagebytes = h * fBpl;
+    if (fimagebytes > 4LL * L_MAX_ALLOWED_PIXELS) {
+        pixDestroy(&pix);
+        return ERROR_INT("image data is too large", __func__, 1);
+    }
+
+        /* If not rgb or 16 bpp, the bmp data is required to have a colormap */
+    heapcm = 0;
+    if (d == 32 || d == 16) {   /* 24 bpp rgb or 16 bpp: no colormap */
+        ncolors = 0;
+        cmaplen = 0;
+    } else if ((cmap = pixGetColormap(pix))) {   /* existing colormap */
+        ncolors = pixcmapGetCount(cmap);
+        cmaplen = ncolors * sizeof(RGBA_QUAD);
+        cta = (l_uint8 *)cmap->array;
+    } else {   /* no existing colormap; d <= 8; make a binary or gray one */
+        if (d == 1) {
+            cmaplen  = sizeof(bwmap);
+            ncolors = 2;
+            cta = (l_uint8 *)bwmap;
+        } else {   /* d = 2,4,8; use a grayscale output colormap */
+            ncolors = 1 << d;
+            cmaplen = ncolors * sizeof(RGBA_QUAD);
+            heapcm = 1;
+            cta = (l_uint8 *)LEPT_CALLOC(cmaplen, 1);
+            stepsize = 255 / (ncolors - 1);
+            for (i = 0, val = 0, pquad = (RGBA_QUAD *)cta;
+                 i < ncolors;
+                 i++, val += stepsize, pquad++) {
+                pquad->blue = pquad->green = pquad->red = val;
+                pquad->alpha = 255;  /* opaque */
+            }
+        }
+    }
+
+#if DEBUG
+    if (pixGetColormap(pix) != NULL) {
+        l_uint8  *pcmptr;
+        pcmptr = (l_uint8 *)pixGetColormap(pix)->array;
+        lept_stderr("Pix colormap[0] = %c%c%c%d\n",
+                    pcmptr[0], pcmptr[1], pcmptr[2], pcmptr[3]);
+        lept_stderr("Pix colormap[1] = %c%c%c%d\n",
+                    pcmptr[4], pcmptr[5], pcmptr[6], pcmptr[7]);
+    }
+#endif  /* DEBUG */
+
+    offbytes = BMP_FHBYTES + BMP_IHBYTES + cmaplen;
+    fsize = offbytes + fimagebytes;
+    fdata = (l_uint8 *)LEPT_CALLOC(fsize, 1);
+    *pfdata = fdata;
+    *pfsize = fsize;
+
+        /* Write little-endian file header data */
+    bmpfh = (BMP_FH *)fdata;
+    bmpfh->bfType[0] = (l_uint8)(BMP_ID >> 0);
+    bmpfh->bfType[1] = (l_uint8)(BMP_ID >> 8);
+    bmpfh->bfSize[0] = (l_uint8)(fsize >>  0);
+    bmpfh->bfSize[1] = (l_uint8)(fsize >>  8);
+    bmpfh->bfSize[2] = (l_uint8)(fsize >> 16);
+    bmpfh->bfSize[3] = (l_uint8)(fsize >> 24);
+    bmpfh->bfOffBits[0] = (l_uint8)(offbytes >>  0);
+    bmpfh->bfOffBits[1] = (l_uint8)(offbytes >>  8);
+    bmpfh->bfOffBits[2] = (l_uint8)(offbytes >> 16);
+    bmpfh->bfOffBits[3] = (l_uint8)(offbytes >> 24);
+
+        /* Convert to little-endian and write the info header data */
+    bmpih.biSize = convertOnBigEnd32(BMP_IHBYTES);
+    bmpih.biWidth = convertOnBigEnd32(w);
+    bmpih.biHeight = convertOnBigEnd32(h);
+    bmpih.biPlanes = convertOnBigEnd16(1);
+    bmpih.biBitCount = convertOnBigEnd16(fdepth);
+    bmpih.biCompression = 0;
+    bmpih.biSizeImage = convertOnBigEnd32(fimagebytes);
+    bmpih.biXPelsPerMeter = convertOnBigEnd32(xres);
+    bmpih.biYPelsPerMeter = convertOnBigEnd32(yres);
+    bmpih.biClrUsed = convertOnBigEnd32(ncolors);
+    bmpih.biClrImportant = convertOnBigEnd32(ncolors);
+    memcpy(fdata + BMP_FHBYTES, &bmpih, BMP_IHBYTES);
+
+        /* Copy the colormap data and free the cta if necessary */
+    if (ncolors > 0) {
+        memcpy(fdata + BMP_FHBYTES + BMP_IHBYTES, cta, cmaplen);
+        if (heapcm) LEPT_FREE(cta);
+    }
+
+        /* When you write a binary image with a colormap
+         * that sets BLACK to 0, you must invert the data */
+    if (fdepth == 1 && cmap && ((l_uint8 *)(cmap->array))[0] == 0x0) {
+        pixInvert(pix, pix);
+    }
+
+        /* An endian byte swap is also required */
+    pixEndianByteSwap(pix);
+
+        /* Transfer the image data.  Image origin for bmp is at lower right. */
+    fmdata = fdata + offbytes;
+    if (fdepth != 24 && fdepth != 32) {   /* typ 1 or 8 bpp */
+        data = (l_uint8 *)pixGetData(pix) + pixBpl * (h - 1);
+        for (i = 0; i < h; i++) {
+            memcpy(fmdata, data, fBpl);
+            data -= pixBpl;
+            fmdata += fBpl;
+        }
+    } else {  /* 32 bpp pix; 24 bpp or 32 bpp file
+             *  See the comments in pixReadStreamBmp() to
+             *  understand the logic behind the pixel ordering below.
+             *  Note that we have again done an endian swap on
+             *  little endian machines before arriving here, so that
+             *  the bytes are ordered on both platforms as:
+             *           Red        Green        Blue         --
+             *      |-----------|------------|-----------|-----------|
+             *
+             *  For writing an spp == 4 file, the code below shows where
+             *  the alpha component is written to file in each pixel.
+             */
+        extrabytes = fBpl - spp * w;
+        line = pixGetData(pix) + pixWpl * (h - 1);
+        for (i = 0; i < h; i++) {
+            for (j = 0; j < w; j++) {
+                pword = line + j;
+                pel[2] = *((l_uint8 *)pword + COLOR_RED);
+                pel[1] = *((l_uint8 *)pword + COLOR_GREEN);
+                pel[0] = *((l_uint8 *)pword + COLOR_BLUE);
+                if (spp == 4)
+                    pel[3] = *((l_uint8 *)pword + L_ALPHA_CHANNEL);
+                memcpy(fmdata, &pel, spp);
+                fmdata += spp;
+            }
+            if (extrabytes) {
+                for (k = 0; k < extrabytes; k++) {
+                    memcpy(fmdata, &pel, 1);
+                    fmdata++;
+                }
+            }
+            line -= pixWpl;
+        }
+    }
+
+    pixDestroy(&pix);
+    return 0;
+}
+
+/* --------------------------------------------*/
+#endif  /* USE_BMPIO */