Try to not dither normalmaps, but instead dither colormaps with higher quality.

diff --git a/misc/tools/cached-converter.sh b/misc/tools/cached-converter.sh
index 2e4ede771bbcf6e1c4799737b26c6342ae420d2a..9fbdf240eb3594fbd3b243fa9a1edf93606bdbdf 100755 (executable)
--- a/misc/tools/cached-converter.sh
+++ b/misc/tools/cached-converter.sh
@@ -402,16 +402,19 @@ for F in "$@"; do
                        export S2TC_COLORDIST_MODE=NORMALMAP
                        export S2TC_RANDOM_COLORS=256
                        export S2TC_REFINE_COLORS=LOOP
+                       export S2TC_DITHER_MODE=NONE
                        ;;
                *_norm)
                        export S2TC_COLORDIST_MODE=NORMALMAP
                        export S2TC_RANDOM_COLORS=256
                        export S2TC_REFINE_COLORS=LOOP
+                       export S2TC_DITHER_MODE=NONE
                        ;;
                *)
                        export S2TC_COLORDIST_MODE=SRGB_MIXED
                        export S2TC_RANDOM_COLORS=64
                        export S2TC_REFINE_COLORS=LOOP
+                       export S2TC_DITHER_MODE=FLOYDSTEINBERG
                        ;;
        esac