diff --git a/pipi/Makefile.am b/pipi/Makefile.am index 5051d02..8c9a0dc 100644 --- a/pipi/Makefile.am +++ b/pipi/Makefile.am @@ -45,6 +45,7 @@ filter_sources = \ dither_sources = \ dither/floydsteinberg.c \ + dither/jajuni.c \ dither/ordered.c \ dither/ostromoukhov.c \ dither/dbs.c \ diff --git a/pipi/context.c b/pipi/context.c index 0c0f6d9..ccfdd18 100644 --- a/pipi/context.c +++ b/pipi/context.c @@ -88,6 +88,10 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...) dst = pipi_dither_floydsteinberg(src, 0); else if(!strcmp(method, "sfs")) dst = pipi_dither_floydsteinberg(src, 1); + else if(!strcmp(method, "jajuni")) + dst = pipi_dither_jajuni(src, 0); + else if(!strcmp(method, "sjajuni")) + dst = pipi_dither_jajuni(src, 1); else if(!strcmp(method, "ost")) dst = pipi_dither_ostromoukhov(src, 0); else if(!strcmp(method, "sost")) diff --git a/pipi/dither/jajuni.c b/pipi/dither/jajuni.c new file mode 100644 index 0000000..45f9aa0 --- /dev/null +++ b/pipi/dither/jajuni.c @@ -0,0 +1,87 @@ +/* + * libpipi Proper image processing implementation library + * Copyright (c) 2004-2008 Sam Hocevar + * All Rights Reserved + * + * $Id$ + * + * This library is free software. It comes without any warranty, to + * the extent permitted by applicable law. You can redistribute it + * and/or modify it under the terms of the Do What The Fuck You Want + * To Public License, Version 2, as published by Sam Hocevar. See + * http://sam.zoy.org/wtfpl/COPYING for more details. + */ + +/* + * jajuni.c: Jarvis-Judice-Ninke dithering functions + */ + +#include "config.h" +#include "common.h" + +#include "pipi.h" +#include "pipi_internals.h" + +pipi_image_t *pipi_dither_jajuni(pipi_image_t *img, pipi_scan_t scan) +{ + pipi_image_t *dst; + pipi_pixels_t *dstp; + float *dstdata; + int x, y, w, h; + + w = img->w; + h = img->h; + + dst = pipi_copy(img); + dstp = pipi_getpixels(dst, PIPI_PIXELS_Y_F); + dstdata = (float *)dstp->pixels; + + for(y = 0; y < h; y++) + { + int reverse = (y & 1) && (scan == PIPI_SCAN_SERPENTINE); + + for(x = 0; x < w; x++) + { + float p, q, e; + int x2 = reverse ? w - 1 - x : x; + int s = reverse ? -1 : 1; + + p = dstdata[y * w + x2]; + q = p < 0.5 ? 0. : 1.; + dstdata[y * w + x2] = q; + + e = (p - q) / 48.; + if(x < w - 1) + dstdata[y * w + x2 + s] += e * 7; + if(x < w - 2) + dstdata[y * w + x2 + s + s] += e * 5; + if(y < h - 1) + { + if(x > 1) + dstdata[(y + 1) * w + x2 - s - s] += e * 3; + if(x > 0) + dstdata[(y + 1) * w + x2 - s] += e * 5; + dstdata[(y + 1) * w + x2] += e * 7; + if(x < w - 1) + dstdata[(y + 1) * w + x2 + s] += e * 5; + if(x < w - 2) + dstdata[(y + 1) * w + x2 + s + s] += e * 3; + } + if(y < h - 2) + { + if(x > 1) + dstdata[(y + 2) * w + x2 - s - s] += e; + if(x > 0) + dstdata[(y + 2) * w + x2 - s] += e * 3; + dstdata[(y + 2) * w + x2] += e * 5; + if(x < w - 1) + dstdata[(y + 2) * w + x2 + s] += e * 3; + if(x < w - 2) + dstdata[(y + 2) * w + x2 + s + s] += e; + } + } + } + + return dst; +} + diff --git a/pipi/pipi.h b/pipi/pipi.h index 3d74c52..0c734b9 100644 --- a/pipi/pipi.h +++ b/pipi/pipi.h @@ -97,6 +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_jajuni(pipi_image_t *, pipi_scan_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);