From 3e6016622e6fc5967e55d41e8074558d43bc33c0 Mon Sep 17 00:00:00 2001 From: Øyvind Kolås Date: Sun, 23 Mar 2014 02:13:26 +0100 Subject: swscale: add two spatially stable dithering methods Both of these dithering methods are from http://pippin.gimp.org/a_dither/ for GIF they can be considered better than bayer (provides more gray-levels), and spatial stability - often more than twice as good compression and less visual flicker than error diffusion methods (the methods also avoids error-shadow artifacts of diffusion dithers). These methods are similar to blue/green noise type dither masks; but are simple enough to generate their mask on the fly. They are still research work in progress; though more expensive to generate masks (which can be used in a LUT) like 'void and cluster' and similar methods will yield superior results --- doc/scaler.texi | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'doc/scaler.texi') diff --git a/doc/scaler.texi b/doc/scaler.texi index f043ffd5f2..23d6393883 100644 --- a/doc/scaler.texi +++ b/doc/scaler.texi @@ -112,6 +112,14 @@ bayer dither @item ed error diffusion dither + +@item a_dither +arithmetic dither, based using addition + +@item x_dither +arithmetic dither, based using xor (more random/less apparent patterning that +a_dither). + @end table @end table -- cgit v1.2.3