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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
- This software is distributed in the hope that it will be
- useful, but with NO WARRANTY OF ANY KIND.
- No author or distributor accepts responsibility to anyone for the
- consequences of using this software, or for whether it serves any
- particular purpose or works at all, unless he or she says so in
- writing. Everyone is granted permission to copy, modify and
- redistribute this source code, for commercial or non-commercial
- purposes, with the following restrictions: (1) the origin of this
- source code must not be misrepresented; (2) modified versions must
- be plainly marked as such; and (3) this notice may not be removed
- or altered from any source or modified source distribution.
*====================================================================*/
/*
* textlinemask.c
*
* This shows examples of finding textline masks for very
* simple geometries. To do this task for more general layout,
* use pagesegtest* programs.
*
* filein: e.g., use arabic.png
* fileout: debug output showing results
*/
#include <stdio.h>
#include <stdlib.h>
#include "allheaders.h"
static const l_int32 DEBUG_OUTPUT = 1;
static const char *seltext = "xxxxxxx"
" x "
" x "
" x "
" x "
" x "
" x "
" x "
"o X o"
" x "
" x "
" x "
" x "
" x "
" x "
" x "
"xxxxxxx";
main(int argc,
char **argv)
{
char *filein, *fileout;
l_int32 w, h, d, w2, h2, i, ncols;
l_float32 angle, conf;
BOX *box;
BOXA *boxa, *boxas, *boxad, *boxa2;
NUMA *numa;
PIX *pixs, *pixt, *pixb, *pixb2, *pixd;
PIX *pixtlm, *pixvws;
PIX *pixt1, *pixt2, *pixt3, *pixt4, *pixt5, *pixt6;
PIXA *pixam, *pixac, *pixad, *pixat;
PIXAA *pixaa, *pixaa2;
PTA *pta;
SEL *selsplit;
static char mainName[] = "textlinemask";
if (argc != 3)
exit(ERROR_INT(" Syntax: textlinemask filein fileout", mainName, 1));
filein = argv[1];
fileout = argv[2];
pixDisplayWrite(NULL, -1); /* init debug output */
if ((pixs = pixRead(filein)) == NULL)
return ERROR_INT("pixs not made", mainName, 1);
pixGetDimensions(pixs, &w, &h, &d);
/* Binarize input */
if (d == 8)
pixt = pixThresholdToBinary(pixs, 128);
else if (d == 1)
pixt = pixClone(pixs);
else {
fprintf(stderr, "depth is %d\n", d);
exit(1);
}
/* Deskew */
pixb = pixFindSkewAndDeskew(pixt, 1, &angle, &conf);
pixDestroy(&pixt);
fprintf(stderr, "Skew angle: %7.2f degrees; %6.2f conf\n", angle, conf);
pixDisplayWrite(pixb, DEBUG_OUTPUT);
#if 1
/* Use full image morphology to find columns, at 2x reduction.
* This only works for very simple layouts where each column
* of text extends the full height of the input image. */
pixb2 = pixReduceRankBinary2(pixb, 2, NULL);
pixt1 = pixMorphCompSequence(pixb2, "c5.500", 0);
pixam; /* Mask with a single component over each column */
boxa = pixConnComp(pixt1, &pixam, 8);
ncols = boxaGetCount(boxa);
fprintf(stderr, "Num columns: %d\n", ncols);
pixDisplayWrite(pixt1, DEBUG_OUTPUT);
/* Use selective region-based morphology to get the textline mask. */
pixad = pixaMorphSequenceByRegion(pixb2, pixam, "c100.3", 0, 0);
pixGetDimensions(pixb2, &w2, &h2, NULL);
if (DEBUG_OUTPUT) {
pixt2 = pixaDisplay(pixad, w2, h2);
pixDisplayWrite(pixt2, DEBUG_OUTPUT);
pixDestroy(&pixt2);
}
/* Some of the lines may be touching, so use a HMT to split the
* lines in each column, and use a pixaa to save the results. */
selsplit = selCreateFromString(seltext, 17, 7, "selsplit");
pixaa = pixaaCreate(ncols);
for (i = 0; i < ncols; i++) {
pixt3 = pixaGetPix(pixad, i, L_CLONE);
box = pixaGetBox(pixad, i, L_COPY);
pixt4 = pixHMT(NULL, pixt3, selsplit);
pixXor(pixt4, pixt4, pixt3);
boxa2 = pixConnComp(pixt4, &pixac, 8);
pixaaAddPixa(pixaa, pixac, L_INSERT);
pixaaAddBox(pixaa, box, L_INSERT);
if (DEBUG_OUTPUT) {
pixt5 = pixaDisplayRandomCmap(pixac, 0, 0);
pixDisplayWrite(pixt5, DEBUG_OUTPUT);
fprintf(stderr, "Num textlines in col %d: %d\n", i,
boxaGetCount(boxa2));
pixDestroy(&pixt5);
}
pixDestroy(&pixt3);
pixDestroy(&pixt4);
boxaDestroy(&boxa2);
}
/* Visual output */
if (DEBUG_OUTPUT) {
system("gthumb junk_write_display* &");
pixat = pixaReadFiles(".", "junk_write_display");
pixt5 = selDisplayInPix(selsplit, 31, 2);
pixaAddPix(pixat, pixt5, L_INSERT);
pixt6 = pixaDisplayTiledAndScaled(pixat, 32, 400, 3, 0, 35, 3);
pixWrite(fileout, pixt6, IFF_PNG);
pixaDestroy(&pixat);
pixDestroy(&pixt6);
}
/* Test pixaa I/O */
pixaaWrite("junkpixaa", pixaa);
pixaa2 = pixaaRead("junkpixaa");
pixaaWrite("junkpixaa2", pixaa2);
/* Test pixaa display */
pixd = pixaaDisplay(pixaa, w2, h2);
pixWrite("junkdisplay", pixd, IFF_PNG);
pixDestroy(&pixd);
/* Cleanup */
pixDestroy(&pixb2);
pixDestroy(&pixt1);
pixaDestroy(&pixam);
pixaDestroy(&pixad);
pixaaDestroy(&pixaa);
pixaaDestroy(&pixaa2);
boxaDestroy(&boxa);
selDestroy(&selsplit);
#endif
#if 0
/* Use the baseline finder; not really what is needed */
numa = pixFindBaselines(pixb, &pta, 1);
#endif
#if 0
/* Use the textline mask function; parameters are not quite right */
pixb2 = pixReduceRankBinary2(pixb, 2, NULL);
pixtlm = pixGenTextlineMask(pixb2, &pixvws, NULL, 1);
pixDisplay(pixtlm, 0, 100);
pixDisplay(pixvws, 500, 100);
pixDestroy(&pixb2);
pixDestroy(&pixtlm);
pixDestroy(&pixvws);
#endif
#if 0
/* Use the Breuel whitespace partition method; slow and we would
* still need to work to extract the fg regions. */
pixb2 = pixReduceRankBinary2(pixb, 2, NULL);
boxas = pixConnComp(pixb2, NULL, 8);
boxad = boxaGetWhiteblocks(boxas, NULL, L_SORT_BY_HEIGHT,
3, 0.1, 200, 0.2, 0);
pixd = pixDrawBoxa(pixb2, boxad, 7, 0xe0708000);
pixDisplay(pixd, 100, 500);
pixDestroy(&pixb2);
pixDestroy(&pixd);
boxaDestroy(&boxas);
boxaDestroy(&boxad);
#endif
#if 0
/* Use morphology to find columns and then selective
* region-based morphology to get the textline mask.
* This is for display; we really want to get a pixa of the
* specific textline masks. */
startTimer();
pixb2 = pixReduceRankBinary2(pixb, 2, NULL);
pixt1 = pixMorphCompSequence(pixb2, "c5.500", 0); /* column mask */
pixt2 = pixMorphSequenceByRegion(pixb2, pixt1, "c100.3", 8, 0, 0, &boxa);
fprintf(stderr, "time = %7.3f sec\n", stopTimer());
pixDisplay(pixt1, 100, 500);
pixDisplay(pixt2, 800, 500);
pixDestroy(&pixb2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
boxaDestroy(&boxa);
#endif
pixDestroy(&pixs);
pixDestroy(&pixb);
exit(0);
}
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