projects / imager.git / blame
| Commit | Line | Data |
|---|---|---|
| 92bda632 TC |
1 | #include "imext.h" |
| 2 | ||
| 3 | char evalstr[]="Description string of plugin dyntest - kind of like"; | |
| 4 | ||
| 5 | void null_plug(void *ptr) { } | |
| 6 | ||
| 7 | /* Example dynamic filter - level stretch (linear) - note it only stretches and doesn't compress */ | |
| 8 | ||
| 9 | /* input parameters | |
| 10 | a: the current black | |
| 11 | b: the current white | |
| 12 | ||
| 13 | 0 <= a < b <= 255; | |
| 14 | ||
| 15 | output pixel value calculated by: o=((i-a)*255)/(b-a); | |
| 16 | ||
| 17 | note that since we do not have the needed functions to manipulate the data structures *** YET *** | |
| 18 | */ | |
| 19 | ||
| 20 | ||
| 21 | unsigned char | |
| 22 | static | |
| 23 | saturate(int in) { | |
| 24 | if (in>255) { return 255; } | |
| 25 | else if (in>0) return in; | |
| 26 | return 0; | |
| 27 | } | |
| 28 | ||
| 29 | void lin_stretch(i_img *im, int a, int b) { | |
| 30 | ||
| 31 | i_color rcolor; | |
| 32 | int i,bytes,x,y; | |
| 33 | int info[4]; | |
| 34 | ||
| 35 | ||
| 36 | /* fprintf(stderr,"parameters: (im 0x%x,a %d,b %d)\n",im,a,b);*/ | |
| 37 | bytes=im->bytes; | |
| 38 | ||
| 39 | i_img_info(im,info); | |
| 40 | ||
| 41 | for(y=0;y<im->ysize;y++) for(x=0;x<im->xsize;x++) { | |
| 42 | i_gpix(im,x,y,&rcolor); | |
| 43 | for(i=0;i<im->channels;i++) rcolor.channel[i]=saturate((255*(rcolor.channel[i]-a))/(b-a)); | |
| 44 | i_ppix(im,x,y,&rcolor); | |
| 45 | } | |
| 46 | ||
| 47 | } | |
| 48 | ||
| 49 |