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| author | Clément Bœsch <u@pkh.me> | 2022-12-30 11:38:13 +0100 |
|---|---|---|
| committer | Clément Bœsch <u@pkh.me> | 2023-01-03 17:29:13 +0100 |
| commit | 68275043a06c532dc573957884186e26637d6c40 (patch) | |
| tree | 590c79ee4c37188309a9d8d8b8e3e44b444a02ef /libavfilter/vf_paletteuse.c | |
| parent | c973e8ae79ae59e7f2d54b6f4c10c2fd91e461da (diff) | |
| download | ffmpeg-68275043a06c532dc573957884186e26637d6c40.tar.gz | |
avfilter/paletteuse: add atkinson dithering
Atkinson according to
https://bisqwit.iki.fi/jutut/kuvat/ordered_dither/error_diffusion.txt:
* 1 1 / 8
1 1 1
1
Diffstat (limited to 'libavfilter/vf_paletteuse.c')
| -rw-r--r-- | libavfilter/vf_paletteuse.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/libavfilter/vf_paletteuse.c b/libavfilter/vf_paletteuse.c index 3c3b6b3ef8..252ad746f0 100644 --- a/libavfilter/vf_paletteuse.c +++ b/libavfilter/vf_paletteuse.c @@ -44,6 +44,7 @@ enum dithering_mode { DITHERING_SIERRA2_4A, DITHERING_SIERRA3, DITHERING_BURKES, + DITHERING_ATKINSON, NB_DITHERING }; @@ -117,6 +118,7 @@ static const AVOption paletteuse_options[] = { { "sierra2_4a", "Frankie Sierra dithering v2 \"Lite\" (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_SIERRA2_4A}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" }, { "sierra3", "Frankie Sierra dithering v3 (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_SIERRA3}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" }, { "burkes", "Burkes dithering (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_BURKES}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" }, + { "atkinson", "Atkinson dithering by Bill Atkinson at Apple Computer (error diffusion)",0, AV_OPT_TYPE_CONST, {.i64=DITHERING_ATKINSON}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" }, { "bayer_scale", "set scale for bayer dithering", OFFSET(bayer_scale), AV_OPT_TYPE_INT, {.i64=2}, 0, 5, FLAGS }, { "diff_mode", "set frame difference mode", OFFSET(diff_mode), AV_OPT_TYPE_INT, {.i64=DIFF_MODE_NONE}, 0, NB_DIFF_MODE-1, FLAGS, "diff_mode" }, { "rectangle", "process smallest different rectangle", 0, AV_OPT_TYPE_CONST, {.i64=DIFF_MODE_RECTANGLE}, INT_MIN, INT_MAX, FLAGS, "diff_mode" }, @@ -418,6 +420,25 @@ static av_always_inline int set_frame(PaletteUseContext *s, AVFrame *out, AVFram if (right2) src[src_linesize + x + 2] = dither_color(src[src_linesize + x + 2], er, eg, eb, 2, 5); } + } else if (dither == DITHERING_ATKINSON) { + const int right = x < w - 1, down = y < h - 1, left = x > x_start; + const int right2 = x < w - 2, down2 = y < h - 2; + const int color = get_dst_color_err(s, src[x], &er, &eg, &eb); + + if (color < 0) + return color; + dst[x] = color; + + if (right) src[ x + 1] = dither_color(src[ x + 1], er, eg, eb, 1, 3); + if (right2) src[ x + 2] = dither_color(src[ x + 2], er, eg, eb, 1, 3); + + if (down) { + if (left) src[src_linesize + x - 1] = dither_color(src[src_linesize + x - 1], er, eg, eb, 1, 3); + if (1) src[src_linesize + x ] = dither_color(src[src_linesize + x ], er, eg, eb, 1, 3); + if (right) src[src_linesize + x + 1] = dither_color(src[src_linesize + x + 1], er, eg, eb, 1, 3); + if (down2) src[src_linesize*2 + x ] = dither_color(src[src_linesize*2 + x ], er, eg, eb, 1, 3); + } + } else { const int color = color_get(s, src[x]); @@ -894,6 +915,7 @@ DEFINE_SET_FRAME(sierra2, DITHERING_SIERRA2) DEFINE_SET_FRAME(sierra2_4a, DITHERING_SIERRA2_4A) DEFINE_SET_FRAME(sierra3, DITHERING_SIERRA3) DEFINE_SET_FRAME(burkes, DITHERING_BURKES) +DEFINE_SET_FRAME(atkinson, DITHERING_ATKINSON) static const set_frame_func set_frame_lut[NB_DITHERING] = { set_frame_none, @@ -904,6 +926,7 @@ static const set_frame_func set_frame_lut[NB_DITHERING] = { set_frame_sierra2_4a, set_frame_sierra3, set_frame_burkes, + set_frame_atkinson, }; static int dither_value(int p) |