/*====================================================================*
 -  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.
 *====================================================================*/

/*
 *  convertfiles.c
 *
 *      Conversion to 1 bpp
 *          l_int32    convertFilesTo1bpp()
 *
 *  These are utility functions that will perform depth conversion
 *  on selected files, writing the results to a specified directory.
 *  We start with conversion to 1 bpp.
 */

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


/*------------------------------------------------------------------*
 *                        Conversion to 1 bpp                       *
 *------------------------------------------------------------------*/
/*!
 *  convertFilesTo1bpp()
 *
 *      Input:  dirin
 *              substr (<optional> substring filter on filenames; can be NULL)
 *              upscaling (1, 2 or 4; only for input color or grayscale)
 *              thresh  (global threshold for binarization; use 0 for default)
 *              firstpage
 *              npages (use 0 to do all from @firstpage to the end)
 *              dirout
 *              outformat (IFF_PNG, IFF_TIFF_G4)
 *      Return: 0 if OK, 1 on error
 *
 *  Notes:
 *      (1) Images are sorted lexicographically, and the names in the
 *          output directory are retained except for the extension.
 */
l_int32
convertFilesTo1bpp(const char  *dirin,
                   const char  *substr,
                   l_int32      upscaling,
                   l_int32      thresh,
                   l_int32      firstpage,
                   l_int32      npages,
                   const char  *dirout,
                   l_int32      outformat)
{
l_int32  i, nfiles;
char     buf[512];
char    *fname, *tail, *basename;
PIX     *pixs, *pixg1, *pixg2, *pixb;
SARRAY  *safiles;

    PROCNAME("convertFilesTo1bpp");

    if (!dirin)
        return ERROR_INT("dirin", procName, 1);
    if (!dirout)
        return ERROR_INT("dirout", procName, 1);
    if (upscaling != 1 && upscaling != 2 && upscaling != 4)
        return ERROR_INT("invalid upscaling factor", procName, 1);
    if (thresh <= 0) thresh = 180;
    if (firstpage < 0) firstpage = 0;
    if (npages < 0) npages = 0;
    if (outformat != IFF_TIFF_G4)
        outformat = IFF_PNG;

    safiles = getSortedPathnamesInDirectory(dirin, substr, firstpage, npages);
    if (!safiles)
        return ERROR_INT("safiles not made", procName, 1);
    if ((nfiles = sarrayGetCount(safiles)) == 0) {
        sarrayDestroy(&safiles);
        return ERROR_INT("no matching files in the directory", procName, 1);
    }

    for (i = 0; i < nfiles; i++) {
        fname = sarrayGetString(safiles, i, L_NOCOPY);
        if ((pixs = pixRead(fname)) == NULL) {
            L_WARNING("Couldn't read file %s\n", procName, fname);
            continue;
        }
        if (pixGetDepth(pixs) == 32)
            pixg1 = pixConvertRGBToLuminance(pixs);
        else
            pixg1 = pixClone(pixs);
        pixg2 = pixRemoveColormap(pixg1, REMOVE_CMAP_TO_GRAYSCALE);
        if (pixGetDepth(pixg2) == 1) {
            pixb = pixClone(pixg2);
        } else {
            if (upscaling == 1)
                pixb = pixThresholdToBinary(pixg2, thresh);
            else if (upscaling == 2)
                pixb = pixScaleGray2xLIThresh(pixg2, thresh);
            else  /* upscaling == 4 */
                pixb = pixScaleGray4xLIThresh(pixg2, thresh);
        }
        pixDestroy(&pixs);
        pixDestroy(&pixg1);
        pixDestroy(&pixg2);

        splitPathAtDirectory(fname, NULL, &tail);
        splitPathAtExtension(tail, &basename, NULL);
        if (outformat == IFF_TIFF_G4) {
            snprintf(buf, sizeof(buf), "%s/%s.tif", dirout, basename);
            pixWrite(buf, pixb, IFF_TIFF_G4);
        } else {
            snprintf(buf, sizeof(buf), "%s/%s.png", dirout, basename);
            pixWrite(buf, pixb, IFF_PNG);
        }
        pixDestroy(&pixb);
        LEPT_FREE(tail);
        LEPT_FREE(basename);
    }

    sarrayDestroy(&safiles);
    return 0;
}
