/*====================================================================*
 -  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 fpix1.c
 * <pre>
 *
 *    ---------------------------------------------------
 *    This file has these FPix, FPixa and DPix utilities:
 *         - creation and destruction
 *         - accessors
 *         - serialization and deserialization
 *    ---------------------------------------------------
 *
 *    FPix Create/copy/destroy
 *          FPIX          *fpixCreate()
 *          FPIX          *fpixCreateTemplate()
 *          FPIX          *fpixClone()
 *          FPIX          *fpixCopy()
 *          void           fpixDestroy()
 *
 *    FPix accessors
 *          l_int32        fpixGetDimensions()
 *          l_int32        fpixSetDimensions()
 *          l_int32        fpixGetWpl()
 *          l_int32        fpixSetWpl()
 *          l_int32        fpixGetResolution()
 *          l_int32        fpixSetResolution()
 *          l_int32        fpixCopyResolution()
 *          l_float32     *fpixGetData()
 *          l_int32        fpixSetData()
 *          l_int32        fpixGetPixel()
 *          l_int32        fpixSetPixel()
 *
 *    FPixa Create/copy/destroy
 *          FPIXA         *fpixaCreate()
 *          FPIXA         *fpixaCopy()
 *          void           fpixaDestroy()
 *
 *    FPixa addition
 *          l_int32        fpixaAddFPix()
 *          static l_int32 fpixaExtendArray()
 *          static l_int32 fpixaExtendArrayToSize()
 *
 *    FPixa accessors
 *          l_int32        fpixaGetCount()
 *          FPIX          *fpixaGetFPix()
 *          l_int32        fpixaGetFPixDimensions()
 *          l_float32     *fpixaGetData()
 *          l_int32        fpixaGetPixel()
 *          l_int32        fpixaSetPixel()
 *
 *    DPix Create/copy/destroy
 *          DPIX          *dpixCreate()
 *          DPIX          *dpixCreateTemplate()
 *          DPIX          *dpixClone()
 *          DPIX          *dpixCopy()
 *          void           dpixDestroy()
 *
 *    DPix accessors
 *          l_int32        dpixGetDimensions()
 *          l_int32        dpixSetDimensions()
 *          l_int32        dpixGetWpl()
 *          l_int32        dpixSetWpl()
 *          l_int32        dpixGetResolution()
 *          l_int32        dpixSetResolution()
 *          l_int32        dpixCopyResolution()
 *          l_float64     *dpixGetData()
 *          l_int32        dpixSetData()
 *          l_int32        dpixGetPixel()
 *          l_int32        dpixSetPixel()
 *
 *    FPix serialized I/O
 *          FPIX          *fpixRead()
 *          FPIX          *fpixReadStream()
 *          FPIX          *fpixReadMem()
 *          l_int32        fpixWrite()
 *          l_int32        fpixWriteStream()
 *          l_int32        fpixWriteMem()
 *          FPIX          *fpixEndianByteSwap()
 *
 *    DPix serialized I/O
 *          DPIX          *dpixRead()
 *          DPIX          *dpixReadStream()
 *          DPIX          *dpixReadMem()
 *          l_int32        dpixWrite()
 *          l_int32        dpixWriteStream()
 *          l_int32        dpixWriteMem()
 *          DPIX          *dpixEndianByteSwap()
 *
 *    Print FPix (subsampled, for debugging)
 *          l_int32        fpixPrintStream()
 * </pre>
 */

#ifdef HAVE_CONFIG_H
#include <config_auto.h>
#endif  /* HAVE_CONFIG_H */

#include <string.h>
#include "allheaders.h"
#include "pix_internal.h"

    /* Bounds on array sizes */
static const size_t  MaxPtrArraySize = 100000;
static const size_t  InitialPtrArraySize = 20;      /*!< n'importe quoi */

    /* Static functions */
static l_int32 fpixaExtendArray(FPIXA *fpixa);
static l_int32 fpixaExtendArrayToSize(FPIXA *fpixa, l_int32 size);

/*--------------------------------------------------------------------*
 *                     FPix Create/copy/destroy                       *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixCreate()
 *
 * \param[in]       width, height
 * \return  fpixd   with data allocated and initialized to 0, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) Makes a FPix of specified size, with the data array
 *          allocated and initialized to 0.
 *      (2) The number of pixels must be less than 2^29.
 * </pre>
 */
FPIX *
fpixCreate(l_int32  width,
           l_int32  height)
{
l_float32  *data;
l_uint64    npix64;
FPIX       *fpixd;

    if (width <= 0)
        return (FPIX *)ERROR_PTR("width must be > 0", __func__, NULL);
    if (height <= 0)
        return (FPIX *)ERROR_PTR("height must be > 0", __func__, NULL);

        /* Avoid overflow in malloc arg, malicious or otherwise */
    npix64 = (l_uint64)width * (l_uint64)height;   /* # of 4-byte pixels */
    if (npix64 >= (1LL << 29)) {
        L_ERROR("requested w = %d, h = %d\n", __func__, width, height);
        return (FPIX *)ERROR_PTR("requested bytes >= 2^31", __func__, NULL);
    }

    fpixd = (FPIX *)LEPT_CALLOC(1, sizeof(FPIX));
    fpixSetDimensions(fpixd, width, height);
    fpixSetWpl(fpixd, width);  /* 4-byte words */
    fpixd->refcount = 1;

    data = (l_float32 *)LEPT_CALLOC((size_t)width * height, sizeof(l_float32));
    if (!data) {
        fpixDestroy(&fpixd);
        return (FPIX *)ERROR_PTR("calloc fail for data", __func__, NULL);
    }
    fpixSetData(fpixd, data);
    return fpixd;
}


/*!
 * \brief   fpixCreateTemplate()
 *
 * \param[in]    fpixs
 * \return  fpixd, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) Makes a FPix of the same size as the input FPix, with the
 *          data array allocated and initialized to 0.
 *      (2) Copies the resolution.
 * </pre>
 */
FPIX *
fpixCreateTemplate(FPIX  *fpixs)
{
l_int32  w, h;
FPIX    *fpixd;

    if (!fpixs)
        return (FPIX *)ERROR_PTR("fpixs not defined", __func__, NULL);

    fpixGetDimensions(fpixs, &w, &h);
    if ((fpixd = fpixCreate(w, h)) == NULL)
        return (FPIX *)ERROR_PTR("fpixd not made", __func__, NULL);
    fpixCopyResolution(fpixd, fpixs);
    return fpixd;
}


/*!
 * \brief   fpixClone()
 *
 * \param[in]    fpix
 * \return  same fpix ptr, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) See pixClone() for definition and usage.
 * </pre>
 */
FPIX *
fpixClone(FPIX  *fpix)
{
    if (!fpix)
        return (FPIX *)ERROR_PTR("fpix not defined", __func__, NULL);
    ++fpix->refcount;

    return fpix;
}


/*!
 * \brief   fpixCopy()
 *
 * \param[in]    fpixs
 * \return  fpixd, or NULL on error
 */
FPIX *
fpixCopy(FPIX  *fpixs)
{
l_int32     w, h, bytes;
l_float32  *datas, *datad;
FPIX       *fpixd;

    if (!fpixs)
        return (FPIX *)ERROR_PTR("fpixs not defined", __func__, NULL);

        /* Total bytes in image data */
    fpixGetDimensions(fpixs, &w, &h);
    bytes = 4 * w * h;

    if ((fpixd = fpixCreateTemplate(fpixs)) == NULL)
        return (FPIX *)ERROR_PTR("fpixd not made", __func__, NULL);
    datas = fpixGetData(fpixs);
    datad = fpixGetData(fpixd);
    memcpy(datad, datas, bytes);
    return fpixd;
}


/*!
 * \brief   fpixDestroy()
 *
 * \param[in,out]   pfpix    will be set to null before returning
 * \return  void
 *
 * <pre>
 * Notes:
 *      (1) Decrements the ref count and, if 0, destroys the fpix.
 *      (2) Always nulls the input ptr.
 * </pre>
 */
void
fpixDestroy(FPIX  **pfpix)
{
l_float32  *data;
FPIX       *fpix;

    if (!pfpix) {
        L_WARNING("ptr address is null!\n", __func__);
        return;
    }

    if ((fpix = *pfpix) == NULL)
        return;

        /* Decrement the ref count.  If it is 0, destroy the fpix. */
    if (--fpix->refcount == 0) {
        if ((data = fpixGetData(fpix)) != NULL)
            LEPT_FREE(data);
        LEPT_FREE(fpix);
    }
    *pfpix = NULL;
}


/*--------------------------------------------------------------------*
 *                          FPix  Accessors                           *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixGetDimensions()
 *
 * \param[in]    fpix
 * \param[out]   pw, ph    [optional] each can be null
 * \return  0 if OK, 1 on error
 */
l_ok
fpixGetDimensions(FPIX     *fpix,
                  l_int32  *pw,
                  l_int32  *ph)
{
    if (!pw && !ph)
        return ERROR_INT("no return val requested", __func__, 1);
    if (pw) *pw = 0;
    if (ph) *ph = 0;
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);
    if (pw) *pw = fpix->w;
    if (ph) *ph = fpix->h;
    return 0;
}


/*!
 * \brief   fpixSetDimensions()
 *
 * \param[in]    fpix
 * \param[in]    w, h
 * \return  0 if OK, 1 on error
 */
l_ok
fpixSetDimensions(FPIX     *fpix,
                  l_int32   w,
                  l_int32   h)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);
    fpix->w = w;
    fpix->h = h;
    return 0;
}


/*!
 * \brief   fpixGetWpl()
 *
 * \param[in]    fpix
 * \return  wpl, or 0 on error
 */
l_int32
fpixGetWpl(FPIX  *fpix)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 0);
    return fpix->wpl;
}


/*!
 * \brief   fpixSetWpl()
 *
 * \param[in]    fpix
 * \param[in]    wpl
 * \return  0 if OK, 1 on error
 */
l_ok
fpixSetWpl(FPIX    *fpix,
           l_int32  wpl)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    fpix->wpl = wpl;
    return 0;
}


/*!
 * \brief   fpixGetResolution()
 *
 * \param[in]    fpix
 * \param[out]   pxres, pyres     [optional] x and y resolution
 * \return  0 if OK, 1 on error
 */
l_ok
fpixGetResolution(FPIX     *fpix,
                  l_int32  *pxres,
                  l_int32  *pyres)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);
    if (pxres) *pxres = fpix->xres;
    if (pyres) *pyres = fpix->yres;
    return 0;
}


/*!
 * \brief   fpixSetResolution()
 *
 * \param[in]    fpix
 * \param[in]    xres, yres     x and y resolution
 * \return  0 if OK, 1 on error
 */
l_ok
fpixSetResolution(FPIX    *fpix,
                  l_int32  xres,
                  l_int32  yres)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    fpix->xres = xres;
    fpix->yres = yres;
    return 0;
}


/*!
 * \brief   fpixCopyResolution()
 *
 * \param[in]    fpixd, fpixs
 * \return  0 if OK, 1 on error
 */
l_ok
fpixCopyResolution(FPIX  *fpixd,
                   FPIX  *fpixs)
{
l_int32  xres, yres;
    if (!fpixs || !fpixd)
        return ERROR_INT("fpixs and fpixd not both defined", __func__, 1);

    fpixGetResolution(fpixs, &xres, &yres);
    fpixSetResolution(fpixd, xres, yres);
    return 0;
}


/*!
 * \brief   fpixGetData()
 *
 * \param[in]    fpix
 * \return  ptr to fpix data, or NULL on error
 */
l_float32 *
fpixGetData(FPIX  *fpix)
{
    if (!fpix)
        return (l_float32 *)ERROR_PTR("fpix not defined", __func__, NULL);
    return fpix->data;
}


/*!
 * \brief   fpixSetData()
 *
 * \param[in]    fpix
 * \param[in]    data
 * \return  0 if OK, 1 on error
 */
l_ok
fpixSetData(FPIX       *fpix,
            l_float32  *data)
{
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    fpix->data = data;
    return 0;
}


/*!
 * \brief   fpixGetPixel()
 *
 * \param[in]    fpix
 * \param[in]    x,y     pixel coords
 * \param[out]   pval    pixel value
 * \return  0 if OK; 1 or 2 on error
 *
 * Notes:
 *      (1) If the point is outside the image, this returns an error (2),
 *          with 0.0 in %pval.  To avoid spamming output, it fails silently.
 */
l_ok
fpixGetPixel(FPIX       *fpix,
             l_int32     x,
             l_int32     y,
             l_float32  *pval)
{
l_int32  w, h;

    if (!pval)
        return ERROR_INT("pval not defined", __func__, 1);
    *pval = 0.0;
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    fpixGetDimensions(fpix, &w, &h);
    if (x < 0 || x >= w || y < 0 || y >= h)
        return 2;

    *pval = *(fpix->data + y * w + x);
    return 0;
}


/*!
 * \brief   fpixSetPixel()
 *
 * \param[in]    fpix
 * \param[in]    x,y    pixel coords
 * \param[in]    val    pixel value
 * \return  0 if OK; 1 or 2 on error
 *
 * Notes:
 *      (1) If the point is outside the image, this returns an error (2),
 *          with 0.0 in %pval.  To avoid spamming output, it fails silently.
 */
l_ok
fpixSetPixel(FPIX      *fpix,
             l_int32    x,
             l_int32    y,
             l_float32  val)
{
l_int32  w, h;

    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    fpixGetDimensions(fpix, &w, &h);
    if (x < 0 || x >= w || y < 0 || y >= h)
        return 2;

    *(fpix->data + y * w + x) = val;
    return 0;
}


/*--------------------------------------------------------------------*
 *                     FPixa Create/copy/destroy                      *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixaCreate()
 *
 * \param[in]    n     initial number of ptrs
 * \return  fpixa, or NULL on error
 */
FPIXA *
fpixaCreate(l_int32  n)
{
FPIXA  *fpixa;

    if (n <= 0 || n > MaxPtrArraySize)
        n = InitialPtrArraySize;

    fpixa = (FPIXA *)LEPT_CALLOC(1, sizeof(FPIXA));
    fpixa->n = 0;
    fpixa->nalloc = n;
    fpixa->refcount = 1;
    fpixa->fpix = (FPIX **)LEPT_CALLOC(n, sizeof(FPIX *));
    return fpixa;
}


/*!
 * \brief   fpixaCopy()
 *
 * \param[in]    fpixa
 * \param[in]    copyflag     L_COPY, L_CLODE or L_COPY_CLONE
 * \return  new fpixa, or NULL on error
 *
 * <pre>
 * Notes:
 *      copyflag may be one of
 *        ~ L_COPY makes a new fpixa and copies each fpix
 *        ~ L_CLONE gives a new ref-counted handle to the input fpixa
 *        ~ L_COPY_CLONE makes a new fpixa with clones of all fpix
 * </pre>
 */
FPIXA *
fpixaCopy(FPIXA   *fpixa,
          l_int32  copyflag)
{
l_int32  i;
FPIX    *fpixc;
FPIXA   *fpixac;

    if (!fpixa)
        return (FPIXA *)ERROR_PTR("fpixa not defined", __func__, NULL);

    if (copyflag == L_CLONE) {
        ++fpixa->refcount;
        return fpixa;
    }

    if (copyflag != L_COPY && copyflag != L_COPY_CLONE)
        return (FPIXA *)ERROR_PTR("invalid copyflag", __func__, NULL);

    if ((fpixac = fpixaCreate(fpixa->n)) == NULL)
        return (FPIXA *)ERROR_PTR("fpixac not made", __func__, NULL);
    for (i = 0; i < fpixa->n; i++) {
        if (copyflag == L_COPY)
            fpixc = fpixaGetFPix(fpixa, i, L_COPY);
        else  /* copy-clone */
            fpixc = fpixaGetFPix(fpixa, i, L_CLONE);
        fpixaAddFPix(fpixac, fpixc, L_INSERT);
    }

    return fpixac;
}


/*!
 * \brief   fpixaDestroy()
 *
 * \param[in,out]   pfpixa    will be set to null before returning
 * \return  void
 *
 * <pre>
 * Notes:
 *      (1) Decrements the ref count and, if 0, destroys the fpixa.
 *      (2) Always nulls the input ptr.
 * </pre>
 */
void
fpixaDestroy(FPIXA  **pfpixa)
{
l_int32  i;
FPIXA   *fpixa;

    if (pfpixa == NULL) {
        L_WARNING("ptr address is NULL!\n", __func__);
        return;
    }

    if ((fpixa = *pfpixa) == NULL)
        return;

        /* Decrement the refcount.  If it is 0, destroy the pixa. */
    if (--fpixa->refcount == 0) {
        for (i = 0; i < fpixa->n; i++)
            fpixDestroy(&fpixa->fpix[i]);
        LEPT_FREE(fpixa->fpix);
        LEPT_FREE(fpixa);
    }
    *pfpixa = NULL;
}


/*--------------------------------------------------------------------*
 *                           FPixa addition                           *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixaAddFPix()
 *
 * \param[in]    fpixa
 * \param[in]    fpix        to be added
 * \param[in]    copyflag    L_INSERT, L_COPY, L_CLONE
 * \return  0 if OK; 1 on error
 */
l_ok
fpixaAddFPix(FPIXA   *fpixa,
             FPIX    *fpix,
             l_int32  copyflag)
{
l_int32  n;
FPIX    *fpixc;

    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    if (copyflag == L_INSERT)
        fpixc = fpix;
    else if (copyflag == L_COPY)
        fpixc = fpixCopy(fpix);
    else if (copyflag == L_CLONE)
        fpixc = fpixClone(fpix);
    else
        return ERROR_INT("invalid copyflag", __func__, 1);
    if (!fpixc)
        return ERROR_INT("fpixc not made", __func__, 1);

    n = fpixaGetCount(fpixa);
    if (n >= fpixa->nalloc) {
        if (fpixaExtendArray(fpixa)) {
            if (copyflag != L_INSERT)
                fpixDestroy(&fpixc);
            return ERROR_INT("extension failed", __func__, 1);
        }
    }
    fpixa->fpix[n] = fpixc;
    fpixa->n++;
    return 0;
}


/*!
 * \brief   fpixaExtendArray()
 *
 * \param[in]    fpixa
 * \return  0 if OK; 1 on error
 *
 * <pre>
 * Notes:
 *      (1) Doubles the size of the fpixa ptr array.
 *      (2) The max number of fpix ptrs is 100000.
 * </pre>
 */
static l_int32
fpixaExtendArray(FPIXA  *fpixa)
{
    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);

    return fpixaExtendArrayToSize(fpixa, 2 * fpixa->nalloc);
}


/*!
 * \brief   fpixaExtendArrayToSize()
 *
 * \param[in]    fpixa
 * \param[in]    size      new ptr array size
 * \return  0 if OK; 1 on error
 *
 * <pre>
 * Notes:
 *      (1) If necessary, reallocs new fpix ptr array to %size.
 *      (2) The max number of fpix ptrs is 100K.
 * </pre>
 */
static l_int32
fpixaExtendArrayToSize(FPIXA   *fpixa,
                       l_int32  size)
{
size_t  oldsize, newsize;

    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);
    if (fpixa->nalloc > MaxPtrArraySize)  /* belt & suspenders */
        return ERROR_INT("fpixa has too many ptrs", __func__, 1);
    if (size > MaxPtrArraySize)
        return ERROR_INT("size > 100K ptrs; too large", __func__, 1);
    if (size <= fpixa->nalloc) {
        L_INFO("size too small; no extension\n", __func__);
        return 0;
    }

    oldsize = fpixa->nalloc * sizeof(FPIX *);
    newsize = size * sizeof(FPIX *);
    if ((fpixa->fpix = (FPIX **)reallocNew((void **)&fpixa->fpix,
                                           oldsize, newsize)) == NULL)
        return ERROR_INT("new ptr array not returned", __func__, 1);
    fpixa->nalloc = size;
    return 0;
}


/*--------------------------------------------------------------------*
 *                          FPixa accessors                           *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixaGetCount()
 *
 * \param[in]    fpixa
 * \return  count, or 0 if no pixa
 */
l_int32
fpixaGetCount(FPIXA  *fpixa)
{
    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 0);

    return fpixa->n;
}


/*!
 * \brief   fpixaGetFPix()
 *
 * \param[in]    fpixa
 * \param[in]    index        to the index-th fpix
 * \param[in]    accesstype   L_COPY or L_CLONE
 * \return  fpix, or NULL on error
 */
FPIX *
fpixaGetFPix(FPIXA   *fpixa,
             l_int32  index,
             l_int32  accesstype)
{
    if (!fpixa)
        return (FPIX *)ERROR_PTR("fpixa not defined", __func__, NULL);
    if (index < 0 || index >= fpixa->n)
        return (FPIX *)ERROR_PTR("index not valid", __func__, NULL);

    if (accesstype == L_COPY)
        return fpixCopy(fpixa->fpix[index]);
    else if (accesstype == L_CLONE)
        return fpixClone(fpixa->fpix[index]);
    else
        return (FPIX *)ERROR_PTR("invalid accesstype", __func__, NULL);
}


/*!
 * \brief   fpixaGetFPixDimensions()
 *
 * \param[in]    fpixa
 * \param[in]    index      to the index-th box
 * \param[out]   pw, ph     [optional] each can be null
 * \return  0 if OK, 1 on error
 */
l_ok
fpixaGetFPixDimensions(FPIXA    *fpixa,
                       l_int32   index,
                       l_int32  *pw,
                       l_int32  *ph)
{
FPIX  *fpix;

    if (!pw && !ph)
        return ERROR_INT("no return val requested", __func__, 1);
    if (pw) *pw = 0;
    if (ph) *ph = 0;
    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);
    if (index < 0 || index >= fpixa->n)
        return ERROR_INT("index not valid", __func__, 1);

    if ((fpix = fpixaGetFPix(fpixa, index, L_CLONE)) == NULL)
        return ERROR_INT("fpix not found!", __func__, 1);
    fpixGetDimensions(fpix, pw, ph);
    fpixDestroy(&fpix);
    return 0;
}


/*!
 * \brief   fpixaGetData()
 *
 * \param[in]    fpixa
 * \param[in]    index     into fpixa array
 * \return  data not a copy, or NULL on error
 */
l_float32 *
fpixaGetData(FPIXA      *fpixa,
             l_int32     index)
{
l_int32     n;
l_float32  *data;
FPIX       *fpix;

    if (!fpixa)
        return (l_float32 *)ERROR_PTR("fpixa not defined", __func__, NULL);
    n = fpixaGetCount(fpixa);
    if (index < 0 || index >= n)
        return (l_float32 *)ERROR_PTR("invalid index", __func__, NULL);

    fpix = fpixaGetFPix(fpixa, index, L_CLONE);
    data = fpixGetData(fpix);
    fpixDestroy(&fpix);
    return data;
}


/*!
 * \brief   fpixaGetPixel()
 *
 * \param[in]    fpixa
 * \param[in]    index     into fpixa array
 * \param[in]    x,y       pixel coords
 * \param[out]   pval      pixel value
 * \return  0 if OK; 1 on error
 */
l_ok
fpixaGetPixel(FPIXA      *fpixa,
              l_int32     index,
              l_int32     x,
              l_int32     y,
              l_float32  *pval)
{
l_int32  n, ret;
FPIX    *fpix;

    if (!pval)
        return ERROR_INT("pval not defined", __func__, 1);
    *pval = 0.0;
    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);
    n = fpixaGetCount(fpixa);
    if (index < 0 || index >= n)
        return ERROR_INT("invalid index into fpixa", __func__, 1);

    fpix = fpixaGetFPix(fpixa, index, L_CLONE);
    ret = fpixGetPixel(fpix, x, y, pval);
    fpixDestroy(&fpix);
    return ret;
}


/*!
 * \brief   fpixaSetPixel()
 *
 * \param[in]    fpixa
 * \param[in]    index    into fpixa array
 * \param[in]    x,y      pixel coords
 * \param[in]    val      pixel value
 * \return  0 if OK; 1 on error
 */
l_ok
fpixaSetPixel(FPIXA     *fpixa,
              l_int32    index,
              l_int32    x,
              l_int32    y,
              l_float32  val)
{
l_int32  n, ret;
FPIX    *fpix;

    if (!fpixa)
        return ERROR_INT("fpixa not defined", __func__, 1);
    n = fpixaGetCount(fpixa);
    if (index < 0 || index >= n)
        return ERROR_INT("invalid index into fpixa", __func__, 1);

    fpix = fpixaGetFPix(fpixa, index, L_CLONE);
    ret = fpixSetPixel(fpix, x, y, val);
    fpixDestroy(&fpix);
    return ret;
}


/*--------------------------------------------------------------------*
 *                     DPix Create/copy/destroy                       *
 *--------------------------------------------------------------------*/
/*!
 * \brief   dpixCreate()
 *
 * \param[in]     width, height
 * \return  dpix  with data allocated and initialized to 0, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) Makes a DPix of specified size, with the data array
 *          allocated and initialized to 0.
 *      (2) The number of pixels must be less than 2^28.
 * </pre>
 */
DPIX *
dpixCreate(l_int32  width,
           l_int32  height)
{
l_float64  *data;
l_uint64    npix64;
DPIX       *dpix;

    if (width <= 0)
        return (DPIX *)ERROR_PTR("width must be > 0", __func__, NULL);
    if (height <= 0)
        return (DPIX *)ERROR_PTR("height must be > 0", __func__, NULL);

        /* Avoid overflow in malloc arg, malicious or otherwise */
    npix64 = (l_uint64)width * (l_uint64)height;   /* # of 8 byte pixels */
    if (npix64 >= (1LL << 28)) {
        L_ERROR("requested w = %d, h = %d\n", __func__, width, height);
        return (DPIX *)ERROR_PTR("requested bytes >= 2^31", __func__, NULL);
    }

    dpix = (DPIX *)LEPT_CALLOC(1, sizeof(DPIX));
    dpixSetDimensions(dpix, width, height);
    dpixSetWpl(dpix, width);  /* 8 byte words */
    dpix->refcount = 1;

    data = (l_float64 *)LEPT_CALLOC((size_t)width * height, sizeof(l_float64));
    if (!data) {
        dpixDestroy(&dpix);
        return (DPIX *)ERROR_PTR("calloc fail for data", __func__, NULL);
    }
    dpixSetData(dpix, data);
    return dpix;
}


/*!
 * \brief   dpixCreateTemplate()
 *
 * \param[in]    dpixs
 * \return  dpixd, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) Makes a DPix of the same size as the input DPix, with the
 *          data array allocated and initialized to 0.
 *      (2) Copies the resolution.
 * </pre>
 */
DPIX *
dpixCreateTemplate(DPIX  *dpixs)
{
l_int32  w, h;
DPIX    *dpixd;

    if (!dpixs)
        return (DPIX *)ERROR_PTR("dpixs not defined", __func__, NULL);

    dpixGetDimensions(dpixs, &w, &h);
    dpixd = dpixCreate(w, h);
    dpixCopyResolution(dpixd, dpixs);
    return dpixd;
}


/*!
 * \brief   dpixClone()
 *
 * \param[in]    dpix
 * \return  same dpix ptr, or NULL on error
 *
 * <pre>
 * Notes:
 *      (1) See pixClone() for definition and usage.
 * </pre>
 */
DPIX *
dpixClone(DPIX  *dpix)
{
    if (!dpix)
        return (DPIX *)ERROR_PTR("dpix not defined", __func__, NULL);
    ++dpix->refcount;
    return dpix;
}


/*!
 * \brief   dpixCopy()
 *
 * \param[in]    dpixs
 * \return  dpixd, or NULL on error
 */
DPIX *
dpixCopy(DPIX  *dpixs)
{
l_int32     w, h, bytes;
l_float64  *datas, *datad;
DPIX       *dpixd;

    if (!dpixs)
        return (DPIX *)ERROR_PTR("dpixs not defined", __func__, NULL);

        /* Total bytes in image data */
    dpixGetDimensions(dpixs, &w, &h);
    bytes = 8 * w * h;

    if ((dpixd = dpixCreateTemplate(dpixs)) == NULL)
        return (DPIX *)ERROR_PTR("dpixd not made", __func__, NULL);
    datas = dpixGetData(dpixs);
    datad = dpixGetData(dpixd);
    memcpy(datad, datas, bytes);
    return dpixd;
}


/*!
 * \brief   dpixDestroy()
 *
 * \param[in,out]   pdpix    will be set to null before returning
 * \return  void
 *
 * <pre>
 * Notes:
 *      (1) Decrements the ref count and, if 0, destroys the dpix.
 *      (2) Always nulls the input ptr.
 * </pre>
 */
void
dpixDestroy(DPIX  **pdpix)
{
l_float64  *data;
DPIX       *dpix;

    if (!pdpix) {
        L_WARNING("ptr address is null!\n", __func__);
        return;
    }

    if ((dpix = *pdpix) == NULL)
        return;

        /* Decrement the ref count.  If it is 0, destroy the dpix. */
    if (--dpix->refcount == 0) {
        if ((data = dpixGetData(dpix)) != NULL)
            LEPT_FREE(data);
        LEPT_FREE(dpix);
    }
    *pdpix = NULL;
}


/*--------------------------------------------------------------------*
 *                          DPix  Accessors                           *
 *--------------------------------------------------------------------*/
/*!
 * \brief   dpixGetDimensions()
 *
 * \param[in]    dpix
 * \param[out]   pw, ph     [optional] each can be null
 * \return  0 if OK, 1 on error
 */
l_ok
dpixGetDimensions(DPIX     *dpix,
                  l_int32  *pw,
                  l_int32  *ph)
{
    if (!pw && !ph)
        return ERROR_INT("no return val requested", __func__, 1);
    if (pw) *pw = 0;
    if (ph) *ph = 0;
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);
    if (pw) *pw = dpix->w;
    if (ph) *ph = dpix->h;
    return 0;
}


/*!
 * \brief   dpixSetDimensions()
 *
 * \param[in]    dpix
 * \param[in]    w, h
 * \return  0 if OK, 1 on error
 */
l_ok
dpixSetDimensions(DPIX     *dpix,
                  l_int32   w,
                  l_int32   h)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);
    dpix->w = w;
    dpix->h = h;
    return 0;
}


/*!
 * \brief   dpixGetWpl()
 *
 * \param[in]    dpix
 * \return  wpl, or 0 on error
 */
l_int32
dpixGetWpl(DPIX  *dpix)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 0);
    return dpix->wpl;
}


/*!
 * \brief   dpixSetWpl()
 *
 * \param[in]    dpix
 * \param[in]    wpl
 * \return  0 if OK, 1 on error
 */
l_ok
dpixSetWpl(DPIX    *dpix,
           l_int32  wpl)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    dpix->wpl = wpl;
    return 0;
}


/*!
 * \brief   dpixGetResolution()
 *
 * \param[in]    dpix
 * \param[out]   pxres, pyres    [optional] x and y resolution
 * \return  0 if OK, 1 on error
 */
l_ok
dpixGetResolution(DPIX     *dpix,
                  l_int32  *pxres,
                  l_int32  *pyres)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);
    if (pxres) *pxres = dpix->xres;
    if (pyres) *pyres = dpix->yres;
    return 0;
}


/*!
 * \brief   dpixSetResolution()
 *
 * \param[in]    dpix
 * \param[in]    xres, yres     x and y resolution
 * \return  0 if OK, 1 on error
 */
l_ok
dpixSetResolution(DPIX    *dpix,
                  l_int32  xres,
                  l_int32  yres)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    dpix->xres = xres;
    dpix->yres = yres;
    return 0;
}


/*!
 * \brief   dpixCopyResolution()
 *
 * \param[in]    dpixd, dpixs
 * \return  0 if OK, 1 on error
 */
l_ok
dpixCopyResolution(DPIX  *dpixd,
                   DPIX  *dpixs)
{
l_int32  xres, yres;
    if (!dpixs || !dpixd)
        return ERROR_INT("dpixs and dpixd not both defined", __func__, 1);

    dpixGetResolution(dpixs, &xres, &yres);
    dpixSetResolution(dpixd, xres, yres);
    return 0;
}


/*!
 * \brief   dpixGetData()
 *
 * \param[in]    dpix
 * \return  ptr to dpix data, or NULL on error
 */
l_float64 *
dpixGetData(DPIX  *dpix)
{
    if (!dpix)
        return (l_float64 *)ERROR_PTR("dpix not defined", __func__, NULL);
    return dpix->data;
}


/*!
 * \brief   dpixSetData()
 *
 * \param[in]    dpix
 * \param[in]    data
 * \return  0 if OK, 1 on error
 */
l_ok
dpixSetData(DPIX       *dpix,
            l_float64  *data)
{
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    dpix->data = data;
    return 0;
}


/*!
 * \brief   dpixGetPixel()
 *
 * \param[in]    dpix
 * \param[in]    x,y     pixel coords
 * \param[out]   pval    pixel value
 * \return  0 if OK; 1 or 2 on error
 *
 * Notes:
 *      (1) If the point is outside the image, this returns an error (2),
 *          with 0.0 in %pval.  To avoid spamming output, it fails silently.
 */
l_ok
dpixGetPixel(DPIX       *dpix,
             l_int32     x,
             l_int32     y,
             l_float64  *pval)
{
l_int32  w, h;

    if (!pval)
        return ERROR_INT("pval not defined", __func__, 1);
    *pval = 0.0;
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    dpixGetDimensions(dpix, &w, &h);
    if (x < 0 || x >= w || y < 0 || y >= h)
        return 2;

    *pval = *(dpix->data + y * w + x);
    return 0;
}


/*!
 * \brief   dpixSetPixel()
 *
 * \param[in]    dpix
 * \param[in]    x,y    pixel coords
 * \param[in]    val    pixel value
 * \return  0 if OK; 1 or 2 on error
 *
 * Notes:
 *      (1) If the point is outside the image, this returns an error (2),
 *          with 0.0 in %pval.  To avoid spamming output, it fails silently.
 */
l_ok
dpixSetPixel(DPIX      *dpix,
             l_int32    x,
             l_int32    y,
             l_float64  val)
{
l_int32  w, h;

    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    dpixGetDimensions(dpix, &w, &h);
    if (x < 0 || x >= w || y < 0 || y >= h)
        return 2;

    *(dpix->data + y * w + x) = val;
    return 0;
}


/*--------------------------------------------------------------------*
 *                       FPix serialized I/O                          *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixRead()
 *
 * \param[in]    filename
 * \return  fpix, or NULL on error
 */
FPIX *
fpixRead(const char  *filename)
{
FILE  *fp;
FPIX  *fpix;

    if (!filename)
        return (FPIX *)ERROR_PTR("filename not defined", __func__, NULL);

    if ((fp = fopenReadStream(filename)) == NULL)
        return (FPIX *)ERROR_PTR_1("stream not opened",
                                   filename, __func__, NULL);
    fpix = fpixReadStream(fp);
    fclose(fp);
    if (!fpix)
        return (FPIX *)ERROR_PTR_1("fpix not read", filename, __func__, NULL);
    return fpix;
}


/*!
 * \brief   fpixReadStream()
 *
 * \param[in]    fp     file stream
 * \return  fpix, or NULL on error
 */
FPIX *
fpixReadStream(FILE  *fp)
{
char        buf[256];
l_int32     w, h, nbytes, xres, yres, version;
l_float32  *data;
FPIX       *fpix;

    if (!fp)
        return (FPIX *)ERROR_PTR("stream not defined", __func__, NULL);

    if (fscanf(fp, "\nFPix Version %d\n", &version) != 1)
        return (FPIX *)ERROR_PTR("not a fpix file", __func__, NULL);
    if (version != FPIX_VERSION_NUMBER)
        return (FPIX *)ERROR_PTR("invalid fpix version", __func__, NULL);
    if (fscanf(fp, "w = %d, h = %d, nbytes = %d\n", &w, &h, &nbytes) != 3)
        return (FPIX *)ERROR_PTR("read fail for data size", __func__, NULL);

        /* Use fgets() and sscanf(); not fscanf(), for the last
         * bit of header data before the float data.  The reason is
         * that fscanf throws away white space, and if the float data
         * happens to begin with ascii character(s) that are white
         * space, it will swallow them and all will be lost!  */
    if (fgets(buf, sizeof(buf), fp) == NULL)
        return (FPIX *)ERROR_PTR("fgets read fail", __func__, NULL);
    if (sscanf(buf, "xres = %d, yres = %d\n", &xres, &yres) != 2)
        return (FPIX *)ERROR_PTR("read fail for xres, yres", __func__, NULL);

    if ((fpix = fpixCreate(w, h)) == NULL)
        return (FPIX *)ERROR_PTR("fpix not made", __func__, NULL);
    fpixSetResolution(fpix, xres, yres);
    data = fpixGetData(fpix);
    if (fread(data, 1, nbytes, fp) != nbytes) {
        fpixDestroy(&fpix);
        return (FPIX *)ERROR_PTR("read error for nbytes", __func__, NULL);
    }
    fgetc(fp);  /* ending nl */

        /* Convert to little-endian if necessary */
    fpixEndianByteSwap(fpix, fpix);
    return fpix;
}


/*!
 * \brief   fpixReadMem()
 *
 * \param[in]    data    of serialized fpix
 * \param[in]    size    of data in bytes
 * \return  fpix, or NULL on error
 */
FPIX *
fpixReadMem(const l_uint8  *data,
            size_t          size)
{
FILE  *fp;
FPIX  *fpix;

    if (!data)
        return (FPIX *)ERROR_PTR("data not defined", __func__, NULL);
    if ((fp = fopenReadFromMemory(data, size)) == NULL)
        return (FPIX *)ERROR_PTR("stream not opened", __func__, NULL);

    fpix = fpixReadStream(fp);
    fclose(fp);
    if (!fpix) L_ERROR("fpix not read\n", __func__);
    return fpix;
}


/*!
 * \brief   fpixWrite()
 *
 * \param[in]    filename
 * \param[in]    fpix
 * \return  0 if OK, 1 on error
 */
l_ok
fpixWrite(const char  *filename,
          FPIX        *fpix)
{
l_int32  ret;
FILE    *fp;

    if (!filename)
        return ERROR_INT("filename not defined", __func__, 1);
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

    if ((fp = fopenWriteStream(filename, "wb")) == NULL)
        return ERROR_INT_1("stream not opened", filename, __func__, 1);
    ret = fpixWriteStream(fp, fpix);
    fclose(fp);
    if (ret)
        return ERROR_INT_1("fpix not written to stream", filename, __func__, 1);
    return 0;
}


/*!
 * \brief   fpixWriteStream()
 *
 * \param[in]    fp       file stream opened for "wb"
 * \param[in]    fpix
 * \return  0 if OK, 1 on error
 */
l_ok
fpixWriteStream(FILE  *fp,
                FPIX  *fpix)
{
l_int32     w, h, xres, yres;
l_uint32    nbytes;
l_float32  *data;
FPIX       *fpixt;

    if (!fp)
        return ERROR_INT("stream not defined", __func__, 1);
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

        /* Convert to little-endian if necessary */
    fpixt = fpixEndianByteSwap(NULL, fpix);

    fpixGetDimensions(fpixt, &w, &h);
    data = fpixGetData(fpixt);
    nbytes = sizeof(l_float32) * w * h;
    fpixGetResolution(fpixt, &xres, &yres);
    fprintf(fp, "\nFPix Version %d\n", FPIX_VERSION_NUMBER);
    fprintf(fp, "w = %d, h = %d, nbytes = %u\n", w, h, nbytes);
    fprintf(fp, "xres = %d, yres = %d\n", xres, yres);
    fwrite(data, 1, nbytes, fp);
    fprintf(fp, "\n");

    fpixDestroy(&fpixt);
    return 0;
}


/*!
 * \brief   fpixWriteMem()
 *
 * \param[out]   pdata     data of serialized fpix
 * \param[out]   psize     size of returned data
 * \param[in]    fpix
 * \return  0 if OK, 1 on error
 *
 * <pre>
 * Notes:
 *      (1) Serializes a fpix in memory and puts the result in a buffer.
 * </pre>
 */
l_ok
fpixWriteMem(l_uint8  **pdata,
             size_t    *psize,
             FPIX      *fpix)
{
l_int32  ret;
FILE    *fp;

    if (pdata) *pdata = NULL;
    if (psize) *psize = 0;
    if (!pdata)
        return ERROR_INT("&data not defined", __func__, 1);
    if (!psize)
        return ERROR_INT("&size not defined", __func__, 1);
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);

#if HAVE_FMEMOPEN
    if ((fp = open_memstream((char **)pdata, psize)) == NULL)
        return ERROR_INT("stream not opened", __func__, 1);
    ret = fpixWriteStream(fp, fpix);
    fputc('\0', fp);
    fclose(fp);
    if (*psize > 0) *psize = *psize - 1;
#else
    L_INFO("no fmemopen API --> work-around: write to temp file\n", __func__);
  #ifdef _WIN32
    if ((fp = fopenWriteWinTempfile()) == NULL)
        return ERROR_INT("tmpfile stream not opened", __func__, 1);
  #else
    if ((fp = tmpfile()) == NULL)
        return ERROR_INT("tmpfile stream not opened", __func__, 1);
  #endif  /* _WIN32 */
    ret = fpixWriteStream(fp, fpix);
    rewind(fp);
    *pdata = l_binaryReadStream(fp, psize);
    fclose(fp);
#endif  /* HAVE_FMEMOPEN */
    return ret;
}


/*!
 * \brief   fpixEndianByteSwap()
 *
 * \param[in]    fpixd     [optional] can be either NULL, or equal to fpixs
 * \param[in]    fpixs
 * \return  fpixd always
 *
 * <pre>
 * Notes:
 *      (1) On big-endian hardware, this does byte-swapping on each of
 *          the 4-byte floats in the fpix data.  On little-endians,
 *          the data is unchanged.  This is used for serialization
 *          of fpix; the data is serialized in little-endian byte
 *          order because most hardware is little-endian.
 *      (2) The operation can be either in-place or, if fpixd == NULL,
 *          a new fpix is made.  If not in-place, caller must catch
 *          the returned pointer.
 * </pre>
 */
FPIX *
fpixEndianByteSwap(FPIX  *fpixd,
                   FPIX  *fpixs)
{
    if (!fpixs)
        return (FPIX *)ERROR_PTR("fpixs not defined", __func__, fpixd);
    if (fpixd && (fpixs != fpixd))
        return (FPIX *)ERROR_PTR("fpixd != fpixs", __func__, fpixd);

#ifdef L_BIG_ENDIAN
    {
    l_uint32  *data;
    l_int32    i, j, w, h;
    l_uint32   word;

        fpixGetDimensions(fpixs, &w, &h);
        if (!fpixd)
            fpixd = fpixCopy(fpixs);

        data = (l_uint32 *)fpixGetData(fpixd);
        for (i = 0; i < h; i++) {
            for (j = 0; j < w; j++, data++) {
                word = *data;
                *data = (word >> 24) |
                        ((word >> 8) & 0x0000ff00) |
                        ((word << 8) & 0x00ff0000) |
                        (word << 24);
            }
        }
        return fpixd;
    }
#else   /* L_LITTLE_ENDIAN */

    if (fpixd)
        return fpixd;  /* no-op */
    else
        return fpixClone(fpixs);

#endif   /* L_BIG_ENDIAN */
}


/*--------------------------------------------------------------------*
 *                       DPix serialized I/O                          *
 *--------------------------------------------------------------------*/
/*!
 * \brief   dpixRead()
 *
 * \param[in]    filename
 * \return  dpix, or NULL on error
 */
DPIX *
dpixRead(const char  *filename)
{
FILE  *fp;
DPIX  *dpix;

    if (!filename)
        return (DPIX *)ERROR_PTR("filename not defined", __func__, NULL);

    if ((fp = fopenReadStream(filename)) == NULL)
        return (DPIX *)ERROR_PTR_1("stream not opened",
                                   filename, __func__, NULL);
    dpix = dpixReadStream(fp);
    fclose(fp);
    if (!dpix)
        return (DPIX *)ERROR_PTR_1("dpix not read", filename, __func__, NULL);
    return dpix;
}


/*!
 * \brief   dpixReadStream()
 *
 * \param[in]    fp      file stream
 * \return  dpix, or NULL on error
 */
DPIX *
dpixReadStream(FILE  *fp)
{
char        buf[256];
l_int32     w, h, nbytes, version, xres, yres;
l_float64  *data;
DPIX       *dpix;

    if (!fp)
        return (DPIX *)ERROR_PTR("stream not defined", __func__, NULL);

    if (fscanf(fp, "\nDPix Version %d\n", &version) != 1)
        return (DPIX *)ERROR_PTR("not a dpix file", __func__, NULL);
    if (version != DPIX_VERSION_NUMBER)
        return (DPIX *)ERROR_PTR("invalid dpix version", __func__, NULL);
    if (fscanf(fp, "w = %d, h = %d, nbytes = %d\n", &w, &h, &nbytes) != 3)
        return (DPIX *)ERROR_PTR("read fail for data size", __func__, NULL);

        /* Use fgets() and sscanf(); not fscanf(), for the last
         * bit of header data before the float data.  The reason is
         * that fscanf throws away white space, and if the float data
         * happens to begin with ascii character(s) that are white
         * space, it will swallow them and all will be lost!  */
    if (fgets(buf, sizeof(buf), fp) == NULL)
        return (DPIX *)ERROR_PTR("fgets read fail", __func__, NULL);
    if (sscanf(buf, "xres = %d, yres = %d\n", &xres, &yres) != 2)
        return (DPIX *)ERROR_PTR("read fail for xres, yres", __func__, NULL);

    if ((dpix = dpixCreate(w, h)) == NULL)
        return (DPIX *)ERROR_PTR("dpix not made", __func__, NULL);
    dpixSetResolution(dpix, xres, yres);
    data = dpixGetData(dpix);
    if (fread(data, 1, nbytes, fp) != nbytes) {
        dpixDestroy(&dpix);
        return (DPIX *)ERROR_PTR("read error for nbytes", __func__, NULL);
    }
    fgetc(fp);  /* ending nl */

        /* Convert to little-endian if necessary */
    dpixEndianByteSwap(dpix, dpix);
    return dpix;
}


/*!
 * \brief   dpixReadMem()
 *
 * \param[in]    data     of serialized dpix
 * \param[in]    size     of data in bytes
 * \return  dpix, or NULL on error
 */
DPIX *
dpixReadMem(const l_uint8  *data,
            size_t          size)
{
FILE  *fp;
DPIX  *dpix;

    if (!data)
        return (DPIX *)ERROR_PTR("data not defined", __func__, NULL);
    if ((fp = fopenReadFromMemory(data, size)) == NULL)
        return (DPIX *)ERROR_PTR("stream not opened", __func__, NULL);

    dpix = dpixReadStream(fp);
    fclose(fp);
    if (!dpix) L_ERROR("dpix not read\n", __func__);
    return dpix;
}


/*!
 * \brief   dpixWrite()
 *
 * \param[in]    filename
 * \param[in]    dpix
 * \return  0 if OK, 1 on error
 */
l_ok
dpixWrite(const char  *filename,
          DPIX        *dpix)
{
l_int32  ret;
FILE    *fp;

    if (!filename)
        return ERROR_INT("filename not defined", __func__, 1);
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

    if ((fp = fopenWriteStream(filename, "wb")) == NULL)
        return ERROR_INT_1("stream not opened", filename, __func__, 1);
    ret = dpixWriteStream(fp, dpix);
    fclose(fp);
    if (ret)
        return ERROR_INT_1("dpix not written to stream", filename, __func__, 1);
    return 0;
}


/*!
 * \brief   dpixWriteStream()
 *
 * \param[in]    fp      file stream opened for "wb"
 * \param[in]    dpix
 * \return  0 if OK, 1 on error
 */
l_ok
dpixWriteStream(FILE  *fp,
                DPIX  *dpix)
{
l_int32     w, h, xres, yres;
l_uint32    nbytes;
l_float64  *data;
DPIX       *dpixt;

    if (!fp)
        return ERROR_INT("stream not defined", __func__, 1);
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

        /* Convert to little-endian if necessary */
    dpixt = dpixEndianByteSwap(NULL, dpix);

    dpixGetDimensions(dpixt, &w, &h);
    dpixGetResolution(dpixt, &xres, &yres);
    data = dpixGetData(dpixt);
    nbytes = sizeof(l_float64) * w * h;
    fprintf(fp, "\nDPix Version %d\n", DPIX_VERSION_NUMBER);
    fprintf(fp, "w = %d, h = %d, nbytes = %u\n", w, h, nbytes);
    fprintf(fp, "xres = %d, yres = %d\n", xres, yres);
    fwrite(data, 1, nbytes, fp);
    fprintf(fp, "\n");

    dpixDestroy(&dpixt);
    return 0;
}


/*!
 * \brief   dpixWriteMem()
 *
 * \param[out]   pdata     data of serialized dpix
 * \param[out]   psize     size of returned data
 * \param[in]    dpix
 * \return  0 if OK, 1 on error
 *
 * <pre>
 * Notes:
 *      (1) Serializes a dpix in memory and puts the result in a buffer.
 * </pre>
 */
l_ok
dpixWriteMem(l_uint8  **pdata,
             size_t    *psize,
             DPIX      *dpix)
{
l_int32  ret;
FILE    *fp;

    if (pdata) *pdata = NULL;
    if (psize) *psize = 0;
    if (!pdata)
        return ERROR_INT("&data not defined", __func__, 1);
    if (!psize)
        return ERROR_INT("&size not defined", __func__, 1);
    if (!dpix)
        return ERROR_INT("dpix not defined", __func__, 1);

#if HAVE_FMEMOPEN
    if ((fp = open_memstream((char **)pdata, psize)) == NULL)
        return ERROR_INT("stream not opened", __func__, 1);
    ret = dpixWriteStream(fp, dpix);
    fputc('\0', fp);
    fclose(fp);
    *psize = *psize - 1;
#else
    L_INFO("no fmemopen API --> work-around: write to temp file\n", __func__);
  #ifdef _WIN32
    if ((fp = fopenWriteWinTempfile()) == NULL)
        return ERROR_INT("tmpfile stream not opened", __func__, 1);
  #else
    if ((fp = tmpfile()) == NULL)
        return ERROR_INT("tmpfile stream not opened", __func__, 1);
  #endif  /* _WIN32 */
    ret = dpixWriteStream(fp, dpix);
    rewind(fp);
    *pdata = l_binaryReadStream(fp, psize);
    fclose(fp);
#endif  /* HAVE_FMEMOPEN */
    return ret;
}


/*!
 * \brief   dpixEndianByteSwap()
 *
 * \param[in]    dpixd     [optional] can be either NULL, or equal to dpixs
 * \param[in]    dpixs
 * \return  dpixd always
 *
 * <pre>
 * Notes:
 *      (1) On big-endian hardware, this does byte-swapping on each of
 *          the 4-byte words in the dpix data.  On little-endians,
 *          the data is unchanged.  This is used for serialization
 *          of dpix; the data is serialized in little-endian byte
 *          order because most hardware is little-endian.
 *      (2) The operation can be either in-place or, if dpixd == NULL,
 *          a new dpix is made.  If not in-place, caller must catch
 *          the returned pointer.
 * </pre>
 */
DPIX *
dpixEndianByteSwap(DPIX  *dpixd,
                   DPIX  *dpixs)
{
    if (!dpixs)
        return (DPIX *)ERROR_PTR("dpixs not defined", __func__, dpixd);
    if (dpixd && (dpixs != dpixd))
        return (DPIX *)ERROR_PTR("dpixd != dpixs", __func__, dpixd);

#ifdef L_BIG_ENDIAN
    {
    l_uint32  *data;
    l_int32    i, j, w, h;
    l_uint32   word;

        dpixGetDimensions(dpixs, &w, &h);
        if (!dpixd)
            dpixd = dpixCopy(dpixs);

        data = (l_uint32 *)dpixGetData(dpixd);
        for (i = 0; i < h; i++) {
            for (j = 0; j < 2 * w; j++, data++) {
                word = *data;
                *data = (word >> 24) |
                        ((word >> 8) & 0x0000ff00) |
                        ((word << 8) & 0x00ff0000) |
                        (word << 24);
            }
        }
        return dpixd;
    }
#else   /* L_LITTLE_ENDIAN */

    if (dpixd)
        return dpixd;  /* no-op */
    else
        return dpixClone(dpixs);

#endif   /* L_BIG_ENDIAN */
}


/*--------------------------------------------------------------------*
 *                 Print FPix (subsampled, for debugging)             *
 *--------------------------------------------------------------------*/
/*!
 * \brief   fpixPrintStream()
 *
 * \param[in]    fp       file stream
 * \param[in]    fpix
 * \param[in]    factor   for subsampling
 * \return  0 if OK, 1 on error
 *
 * <pre>
 * Notes:
 *      (1) Subsampled printout of fpix for debugging.
 * </pre>
 */
l_ok
fpixPrintStream(FILE    *fp,
                FPIX    *fpix,
                l_int32  factor)
{
l_int32    i, j, w, h, count;
l_float32  val;

    if (!fp)
        return ERROR_INT("stream not defined", __func__, 1);
    if (!fpix)
        return ERROR_INT("fpix not defined", __func__, 1);
    if (factor < 1)
        return ERROR_INT("sampling factor < 1f", __func__, 1);

    fpixGetDimensions(fpix, &w, &h);
    fprintf(fp, "\nFPix: w = %d, h = %d\n", w, h);
    for (i = 0; i < h; i += factor) {
        for (count = 0, j = 0; j < w; j += factor, count++) {
            fpixGetPixel(fpix, j, i, &val);
            fprintf(fp, "val[%d, %d] = %f   ", i, j, val);
            if ((count + 1) % 3 == 0) fprintf(fp, "\n");
        }
        if (count % 3) fprintf(fp, "\n");
     }
     fprintf(fp, "\n");
     return 0;
}