1 #define IMAGER_NO_CONTEXT
6 gauss(int x, double std) {
7 return 1.0/(sqrt(2.0*PI)*std)*exp(-(double)(x)*(double)(x)/(2*std*std));
10 /* Counters are as follows
15 pc: coeff equalization
21 i_gaussian(i_img *im, double stddev) {
26 double res[MAXCHANNELS];
31 im_log((aIMCTX, 1,"i_gaussian(im %p, stdev %.2f)\n",im,stddev));
35 i_push_error(0, "stddev must be positive");
38 /* totally silly cutoff */
43 timg = i_sametype(im, im->xsize, im->ysize);
46 radius = ceil(2 * stddev);
48 radius = ceil(3 * stddev);
50 diameter = 1 + radius * 2;
52 coeff = mymalloc(sizeof(double) * diameter);
54 for(i=0;i <= radius;i++)
55 coeff[radius + i]=coeff[radius - i]=gauss(i, stddev);
57 for(i=0; i < diameter; i++)
59 for(i=0;i < diameter;i++)
65 for(y = 0; y < im->ysize; y++) {
66 for(x = 0; x < im->xsize; x++) {
68 for(ch=0;ch<im->channels;ch++)
70 for(c = 0;c < diameter; c++)
71 if (IM_GPIX(im,x+c-radius,y,&rcolor)!=-1) {
72 for(ch=0;ch<im->channels;ch++)
73 res[ch]+= rcolor.channel[ch] * coeff[c];
76 for(ch=0;ch<im->channels;ch++) {
77 double value = res[ch] / pc;
78 rcolor.channel[ch] = value > IM_SAMPLE_MAX ? IM_SAMPLE_MAX : IM_ROUND(value);
80 IM_PPIX(timg, x, y, &rcolor);
84 for(x = 0;x < im->xsize; x++) {
85 for(y = 0; y < im->ysize; y++) {
87 for(ch=0; ch<im->channels; ch++)
89 for(c=0; c < diameter; c++)
90 if (IM_GPIX(timg, x, y+c-radius, &rcolor)!=-1) {
91 for(ch=0;ch<im->channels;ch++)
92 res[ch]+= rcolor.channel[ch] * coeff[c];
95 for(ch=0;ch<im->channels;ch++) {
96 double value = res[ch]/pc;
97 rcolor.channel[ch] = value > IM_SAMPLE_MAX ? IM_SAMPLE_MAX : IM_ROUND(value);
99 IM_PPIX(im, x, y, &rcolor);