diff --git a/pipi/context.c b/pipi/context.c index 0a032a0..ad4be46 100644 --- a/pipi/context.c +++ b/pipi/context.c @@ -93,7 +93,13 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...) else if(!strcmp(method, "sost")) dst = pipi_dither_ostromoukhov(src, 1); else if(!strcmp(method, "ordered")) - dst = pipi_dither_ordered(src); + { + if(ctx->nimages < 2) + return -1; + dst = pipi_dither_ordered(ctx->images[ctx->nimages - 2], src); + pipi_free(ctx->images[ctx->nimages - 2]); + ctx->nimages--; + } else if(!strcmp(method, "random")) dst = pipi_dither_random(src); else if(!strcmp(method, "dbs")) diff --git a/pipi/dither/ordered.c b/pipi/dither/ordered.c index b72e154..781d6b3 100644 --- a/pipi/dither/ordered.c +++ b/pipi/dither/ordered.c @@ -22,32 +22,25 @@ #include "pipi.h" #include "pipi_internals.h" -static const int kernel8x8[8 * 8] = -{ - 0, 32, 8, 40, 2, 34, 10, 42, - 48, 16, 56, 24, 50, 18, 58, 26, - 12, 44, 4, 36, 14, 46, 6, 38, - 60, 28, 52, 20, 62, 30, 54, 22, - 3, 35, 11, 43, 1, 33, 9, 41, - 51, 19, 59, 27, 49, 17, 57, 25, - 15, 47, 7, 39, 13, 45, 5, 37, - 63, 31, 55, 23, 61, 29, 53, 21, -}; - -pipi_image_t *pipi_dither_ordered(pipi_image_t *img) +pipi_image_t *pipi_dither_ordered(pipi_image_t *img, pipi_image_t *kernel) { pipi_image_t *dst; - pipi_pixels_t *dstp; - float *dstdata; - int x, y, w, h; + pipi_pixels_t *dstp, *kernelp; + float *dstdata, *kerneldata; + int x, y, w, h, kw, kh; w = img->w; h = img->h; + kw = kernel->w; + kh = kernel->h; dst = pipi_copy(img); dstp = pipi_getpixels(dst, PIPI_PIXELS_Y_F); dstdata = (float *)dstp->pixels; + kernelp = pipi_getpixels(kernel, PIPI_PIXELS_Y_F); + kerneldata = (float *)kernelp->pixels; + for(y = 0; y < h; y++) { for(x = 0; x < w; x++) @@ -55,7 +48,7 @@ pipi_image_t *pipi_dither_ordered(pipi_image_t *img) float p, q; p = dstdata[y * w + x]; - q = p > (1. + kernel8x8[(y % 8) * 8 + (x % 8)]) / 65. ? 1. : 0.; + q = p > kerneldata[(y % kh) * kw + (x % kw)] ? 1. : 0.; dstdata[y * w + x] = q; } } diff --git a/pipi/pipi.h b/pipi/pipi.h index e963f8b..3d74c52 100644 --- a/pipi/pipi.h +++ b/pipi/pipi.h @@ -97,7 +97,7 @@ extern int pipi_flood_fill(pipi_image_t *, int, int, float, float, float, float); extern pipi_image_t *pipi_dither_floydsteinberg(pipi_image_t *, pipi_scan_t); -extern pipi_image_t *pipi_dither_ordered(pipi_image_t *); +extern pipi_image_t *pipi_dither_ordered(pipi_image_t *, pipi_image_t *); extern pipi_image_t *pipi_dither_random(pipi_image_t *); extern pipi_image_t *pipi_dither_ostromoukhov(pipi_image_t *, pipi_scan_t); extern pipi_image_t *pipi_dither_dbs(pipi_image_t *);