Fixed palette index for zeroed color in FASTOCTREE quantize#5869
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hugovk merged 1 commit intopython-pillow:mainfrom Dec 28, 2021
Merged
Fixed palette index for zeroed color in FASTOCTREE quantize#5869hugovk merged 1 commit intopython-pillow:mainfrom
hugovk merged 1 commit intopython-pillow:mainfrom
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Helps #4640
When using
quantize(), most methods place the colors into the palette and then fill up the remaining colors with "\x00\x00\x00"You can see that the first part of the palette is the
(255, 0, 0).So what if the color in the image was actually
(0, 0, 0)?Still working as expected. However, for
Image.FASTOCTREE,it actually uses the last palette entry rather than the first. So the
ImagePalette.colorsends up being wrong.>>> quantized_im.palette.colors {(0, 0, 0): 0}This PR fixes this by just setting the palette colors in decreasing order instead of increasing, so that the operation to set (0, 0, 0) to 0 now comes after the operation to set (0, 0, 0) to 255.