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/*====================================================================*
- 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.
*====================================================================*/
/*
* livre_adapt.c
*
* This shows two ways to normalize a document image for uneven
* illumination. It is somewhat more complicated than using the
* morphological tophat.
*/
#ifdef HAVE_CONFIG_H
#include <config_auto.h>
#endif /* HAVE_CONFIG_H */
#include "allheaders.h"
int main(int argc,
char **argv)
{
PIX *pixs, *pix1, *pix2, *pix3, *pixr, *pixg, *pixb, *pixsg, *pixsm;
PIXA *pixa;
static char mainName[] = "livre_adapt";
if (argc != 1)
return ERROR_INT(" Syntax: livre_adapt", mainName, 1);
setLeptDebugOK(1);
/* Read the image in at 150 ppi. */
if ((pixs = pixRead("brothers.150.jpg")) == NULL)
return ERROR_INT("pix not made", mainName, 1);
pixa = pixaCreate(0);
pixaAddPix(pixa, pixs, L_INSERT);
/* Normalize for uneven illumination on RGB image */
pixBackgroundNormRGBArraysMorph(pixs, NULL, 4, 5, 200,
&pixr, &pixg, &pixb);
pix1 = pixApplyInvBackgroundRGBMap(pixs, pixr, pixg, pixb, 4, 4);
pixaAddPix(pixa, pix1, L_INSERT);
pixDestroy(&pixr);
pixDestroy(&pixg);
pixDestroy(&pixb);
/* Convert the RGB image to grayscale. */
pixsg = pixConvertRGBToLuminance(pixs);
pixaAddPix(pixa, pixsg, L_INSERT);
/* Remove the text in the fg. */
pix1 = pixCloseGray(pixsg, 25, 25);
pixaAddPix(pixa, pix1, L_INSERT);
/* Smooth the bg with a convolution. */
pixsm = pixBlockconv(pix1, 15, 15);
pixaAddPix(pixa, pixsm, L_INSERT);
/* Normalize for uneven illumination on gray image. */
pixBackgroundNormGrayArrayMorph(pixsg, NULL, 4, 5, 200, &pixg);
pix1 = pixApplyInvBackgroundGrayMap(pixsg, pixg, 4, 4);
pixaAddPix(pixa, pix1, L_INSERT);
pixDestroy(&pixg);
/* Increase the dynamic range. */
pix2 = pixGammaTRC(NULL, pix1, 1.0, 30, 180);
pixaAddPix(pixa, pix2, L_INSERT);
/* Threshold to 1 bpp. */
pix3 = pixThresholdToBinary(pix2, 120);
pixaAddPix(pixa, pix3, L_INSERT);
/* Generate the output image and pdf */
lept_mkdir("lept/livre");
lept_stderr("Writing jpg and pdf to: /tmp/lept/livre/adapt.*\n");
pix1 = pixaDisplayTiledAndScaled(pixa, 8, 350, 4, 0, 25, 2);
pixWrite("/tmp/lept/livre/adapt.jpg", pix1, IFF_DEFAULT);
pixDisplay(pix1, 100, 100);
pixaConvertToPdf(pixa, 0, 1.0, 0, 0, "Livre: adaptive thresholding",
"/tmp/lept/livre/adapt.pdf");
pixDestroy(&pix1);
pixaDestroy(&pixa);
return 0;
}
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