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rewrite random noise knowing how bayer works

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David 2021-01-12 20:27:42 -05:00
parent 4c0678cf77
commit 94d1e465c9
1 changed files with 2 additions and 5 deletions
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7
color_quant.go
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@ -48,15 +48,12 @@ func naivePalette(p color.Palette) quantizerFunction {
// randomNoisePalette injects random noise into the quantization step // randomNoisePalette injects random noise into the quantization step
func randomNoisePalette(p color.Palette) quantizerFunction { func randomNoisePalette(p color.Palette) quantizerFunction {
r := len(p)
return func(_, _ int, c color.Color) color.Color { return func(_, _ int, c color.Color) color.Color {
// the randomization here is tuned for the sixteen-color palette for now.
// I think the proper theory here is probably "only try and randomize within one palette swatch in either direction". // I think the proper theory here is probably "only try and randomize within one palette swatch in either direction".
// it might be possible to instead permute the color selected _from the palette_ (i.e. modify the result of p.Index(c))... // it might be possible to instead permute the color selected _from the palette_ (i.e. modify the result of p.Index(c))...
// ...but I think for that to work you'd need a proper "ordering" for the colors. // ...but I think for that to work you'd need a proper "ordering" for the colors.
noise := rand.Intn(64) - 32 noise := rand.Intn(256) / r
if noise < 0 {
noise = 0
}
rc := permuteColor(c, uint8(noise)) rc := permuteColor(c, uint8(noise))
return p[p.Index(rc)] return p[p.Index(rc)]
} }