static MagickBooleanType SigmoidalContrast(ImageView *contrast_view,
const ssize_t y,const int id,void *context)
{
#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)
RectangleInfo
extent;
register IndexPacket
*indexes;
register PixelPacket
*pixels;
register ssize_t
x;
extent=GetImageViewExtent(contrast_view);
pixels=GetImageViewAuthenticPixels(contrast_view);
for (x=0; x < (ssize_t) (extent.width-extent.height); x++)
{
pixels[x].red=RoundToQuantum(SigmoidalContrast(pixels[x].red));
pixels[x].green=RoundToQuantum(SigmoidalContrast(pixels[x].green));
pixels[x].blue=RoundToQuantum(SigmoidalContrast(pixels[x].blue));
pixels[x].opacity=RoundToQuantum(SigmoidalContrast(pixels[x].opacity));
}
indexes=GetImageViewAuthenticIndexes(contrast_view);
if (indexes != (IndexPacket *) NULL)
for (x=0; x < (ssize_t) (extent.width-extent.height); x++)
indexes[x]=(IndexPacket) RoundToQuantum(SigmoidalContrast(indexes[x]));
return(MagickTrue);
}
int main(int argc, char **argv)
{
printf("Hello World\n");
#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);\
exit(-1);\
}
long y;
MagickBooleanType status;
MagickPixelPacket pixel;
MagickWand *contrast_wand, *image_wand;
PixelIterator *contrast_iterator,*iterator;
PixelWand **contrast_pixels, **pixels;
register long x;
unsigned long width;
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<(long)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<(long)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);
PixelSetMagickColor(contrast_pixels[x],&pixel);
}
(void)PixelSyncIterator(contrast_iterator);
}
if(y < (long)MagickGetImageHeight(image_wand))
ThrowWandException(image_wand);
contrast_iterator = DestroyPixelIterator(contrast_iterator);
iterator = DestroyPixelIterator(iterator);
image_wand=DestroyMagickWand(image_wand);
status = MagickWriteImages(contrast_wand,argv[2],MagickTrue);
if(status == MagickFalse)
ThrowWandException(image_wand);
contrast_wand = DestroyMagickWand(contrast_wand);
MagickWandTerminus();
return 0;
}
