1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <math.h> 4 #include <wand/MagickWand.h> 5 6 static MagickBooleanType SigmoidalContrast(WandView *contrast_view, 7 const ssize_t y,const int id,void *context) 8 { 9 #define QuantumScale ((MagickRealType) 1.0/(MagickRealType) QuantumRange) 10 #define SigmoidalContrast(x) \ 11 (QuantumRange*(1.0/(1+exp(10.0*(0.5-QuantumScale*x)))-0.0066928509)*1.0092503) 12 13 RectangleInfo 14 extent; 15 16 MagickPixelPacket 17 pixel; 18 19 PixelWand 20 **pixels; 21 22 register ssize_t 23 x; 24 25 extent=GetWandViewExtent(contrast_view); 26 pixels=GetWandViewPixels(contrast_view); 27 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 28 { 29 PixelGetMagickColor(pixels[x],&pixel); 30 pixel.red=SigmoidalContrast(pixel.red); 31 pixel.green=SigmoidalContrast(pixel.green); 32 pixel.blue=SigmoidalContrast(pixel.blue); 33 pixel.index=SigmoidalContrast(pixel.index); 34 PixelSetMagickColor(pixels[x],&pixel); 35 } 36 return(MagickTrue); 37 } 38 39 int main(int argc,char **argv) 40 { 41 #define ThrowViewException(view) \ 42 { \ 43 description=GetWandViewException(view,&severity); \ 44 (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ 45 description=(char *) MagickRelinquishMemory(description); \ 46 exit(-1); \ 47 } 48 #define ThrowWandException(wand) \ 49 { \ 50 description=MagickGetException(wand,&severity); \ 51 (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ 52 description=(char *) MagickRelinquishMemory(description); \ 53 exit(-1); \ 54 } 55 56 char 57 *description; 58 59 ExceptionType 60 severity; 61 62 MagickBooleanType 63 status; 64 65 MagickPixelPacket 66 pixel; 67 68 MagickWand 69 *contrast_wand; 70 71 WandView 72 *contrast_view; 73 74 if (argc != 3) 75 { 76 (void) fprintf(stdout,"Usage: %s image sigmoidal-image\n",argv[0]); 77 exit(0); 78 } 79 /* 80 Read an image. 81 */ 82 MagickWandGenesis(); 83 contrast_wand=NewMagickWand(); 84 status=MagickReadImage(contrast_wand,argv[1]); 85 if (status == MagickFalse) 86 ThrowWandException(contrast_wand); 87 /* 88 Sigmoidal non-linearity contrast control. 89 */ 90 contrast_view=NewWandView(contrast_wand); 91 if (contrast_view == (WandView *) NULL) 92 ThrowWandException(contrast_wand); 93 status=UpdateWandViewIterator(contrast_view,SigmoidalContrast,(void *) NULL); 94 if (status == MagickFalse) 95 ThrowWandException(contrast_wand); 96 contrast_view=DestroyWandView(contrast_view); 97 /* 98 Write the image then destroy it. 99 */ 100 status=MagickWriteImages(contrast_wand,argv[2],MagickTrue); 101 if (status == MagickFalse) 102 ThrowWandException(contrast_wand); 103 contrast_wand=DestroyMagickWand(contrast_wand); 104 MagickWandTerminus(); 105 return(0); 106 } 107
