Created
March 9, 2017 23:50
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#include <stdio.h> | |
#include <stdlib.h> | |
#include <math.h> | |
#include <MagickWand/MagickWand.h> | |
int main(int argc,char **argv) | |
{ | |
#define QuantumScale ((MagickRealType) 1.0/(MagickRealType) QuantumRange) | |
#define SigmoidalContrast(x) \ | |
(QuantumRange*(1.0/(1+exp(10.0*(0.5-QuantumScale*x)))-0.0066928509)*1.0092503) | |
#define ThrowWandException(wand) \ | |
{ \ | |
char \ | |
*description; \ | |
\ | |
ExceptionType \ | |
severity; \ | |
\ | |
description=MagickGetException(wand,&severity); \ | |
(void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ | |
description=(char *) MagickRelinquishMemory(description); \ | |
exit(-1); \ | |
} | |
MagickBooleanType | |
status; | |
PixelInfo | |
pixel; | |
MagickWand | |
*contrast_wand, | |
*image_wand; | |
PixelIterator | |
*contrast_iterator, | |
*iterator; | |
PixelWand | |
**contrast_pixels, | |
**pixels; | |
register ssize_t | |
x; | |
size_t | |
width; | |
ssize_t | |
y; | |
if (argc != 3) | |
{ | |
(void) fprintf(stdout,"Usage: %s image sigmoidal-image\n",argv[0]); | |
exit(0); | |
} | |
/* | |
Read an image. | |
*/ | |
MagickWandGenesis(); | |
image_wand=NewMagickWand(); | |
status=MagickReadImage(image_wand,argv[1]); | |
if (status == MagickFalse) | |
ThrowWandException(image_wand); | |
contrast_wand=CloneMagickWand(image_wand); | |
/* | |
Sigmoidal non-linearity contrast control. | |
*/ | |
iterator=NewPixelIterator(image_wand); | |
contrast_iterator=NewPixelIterator(contrast_wand); | |
if ((iterator == (PixelIterator *) NULL) || | |
(contrast_iterator == (PixelIterator *) NULL)) | |
ThrowWandException(image_wand); | |
for (y=0; y < (ssize_t) MagickGetImageHeight(image_wand); y++) | |
{ | |
pixels=PixelGetNextIteratorRow(iterator,&width); | |
contrast_pixels=PixelGetNextIteratorRow(contrast_iterator,&width); | |
if ((pixels == (PixelWand **) NULL) || | |
(contrast_pixels == (PixelWand **) NULL)) | |
break; | |
for (x=0; x < (ssize_t) width; x++) | |
{ | |
PixelGetMagickColor(pixels[x],&pixel); | |
pixel.red=SigmoidalContrast(pixel.red); | |
pixel.green=SigmoidalContrast(pixel.green); | |
pixel.blue=SigmoidalContrast(pixel.blue); | |
pixel.index=SigmoidalContrast(pixel.index); | |
PixelSetPixelColor(contrast_pixels[x],&pixel); | |
} | |
(void) PixelSyncIterator(contrast_iterator); | |
} | |
if (y < (ssize_t) MagickGetImageHeight(image_wand)) | |
ThrowWandException(image_wand); | |
contrast_iterator=DestroyPixelIterator(contrast_iterator); | |
iterator=DestroyPixelIterator(iterator); | |
image_wand=DestroyMagickWand(image_wand); | |
/* | |
Write the image then destroy it. | |
*/ | |
status = MagickStripImage(contrast_wand); | |
if (status == MagickFalse) | |
ThrowWandException(image_wand); | |
status=MagickWriteImage(contrast_wand,argv[2]); | |
if (status == MagickFalse) | |
ThrowWandException(image_wand); | |
contrast_wand=DestroyMagickWand(contrast_wand); | |
MagickWandTerminus(); | |
return(0); | |
} |
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