Add rawmode argument to Image.getpalette()

[tswast]

putpalette has a rawmode argument which accepts "RGBA", allowing a palette with some transparent colors. Unfortunately getpalette does not have a similar argument.

In most but not all of the images I'm working with, the first two elements of the palette are both (0, 0, 0), with the first element corresponding to the transparent color (0, 0, 0, 0) and the second corresponding to (0, 0, 0, 255). I was able to figure this out through experimentation, but would prefer to be more precise, as I have a few images where this is not the case.

Current code:

def recolor_poodle(original_path, new_path):
    image = Image.open(original_path)
    image = image.convert("P")
    unused_palette = 127
    ImageDraw.floodfill(image, (31, 21), unused_palette)
    original_palette = image.getpalette()
    new_palette = [0, 0, 0, 0]
    for palette_index in range(1, len(original_palette) // 3):
        old_rgb = [
            original_palette[3 * palette_index + channel_index]
            for channel_index in range(3)
        ]
        channels = [hex(channel)[2:].rjust(2, "0") for channel in old_rgb]
        # padding
        old_color = f"{channels[0]}{channels[1]}{channels[2]}"
        new_color = OLD_TO_NEW.get(old_color)
        if new_color is None:
            new_palette += old_rgb + [255]
        else:
            new_palette += [
                int(new_color[0:2], base=16),
                int(new_color[2:4], base=16),
                int(new_color[4:6], base=16),
                255,
            ]

    arr = numpy.asarray(image)

    im2 = Image.fromarray(arr, mode="P")
    im2.putpalette(new_palette, rawmode="RGBA")
    im2.save(new_path)

Desired code:

def recolor_poodle(original_path, new_path):
    image = Image.open(original_path)
    image = image.convert("P")
    unused_palette = 127
    ImageDraw.floodfill(image, (31, 21), unused_palette)
    original_palette = image.getpalette(rawmode="RGBA")
    new_palette = []
    for palette_index in range(len(original_palette) // 4):
        # Skip mapping transparent colors.
        if original_palette[4 * palette_index + 3] == 0:
            new_palette += [0, 0, 0, 0]
            continue
        old_rgb = [
            original_palette[4 * palette_index + channel_index]
            for channel_index in range(3)
        ]
        channels = [hex(channel)[2:].rjust(2, "0") for channel in old_rgb]
        # padding
        old_color = f"{channels[0]}{channels[1]}{channels[2]}"
        new_color = OLD_TO_NEW.get(old_color)
        if new_color is None:
            new_palette += old_rgb + [255]
        else:
            new_palette += [
                int(new_color[0:2], base=16),
                int(new_color[2:4], base=16),
                int(new_color[4:6], base=16),
                255,
            ]

    arr = numpy.asarray(image)

    im2 = Image.fromarray(arr, mode="P")
    im2.putpalette(new_palette, rawmode="RGBA")
    im2.save(new_path)

[radarhere]

Hi. While your feature request may still stand, I suggest talking a look at image.palette.colors. I expect that will solve your problem.

[radarhere]

I've created PR #6061 to resolve this.

[CookiePLMonster]

I believe this satisfies the wish I had in one of the replies in #6027 (comment). Very happy to see this.