ICO: Ignore AND mask for 32bpp images with native alpha#3002
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Could you please show that this is correct? Just because applying the AND mask is destructive doesn't mean we can just ignore it. So could you please find relevant documentation that supports your change and/or show that other widely used decoders behave equivalently? I think an example image would really help here. Then we could just see what other programs are doing. |
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June 2, 2026 14:18
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@RunDevelopment thank you for the comment! As I've understood it from here, Windows looks at the alpha channel for 32bpp images during standard rendering and does not apply the AND mask |
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Thank you, behavior checks against Chromium, Firefox, feh, eog also check out with the test image.
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2bpp BMPs already have a native alpha channel, so applying the 1-bit AND mask is destructive, as it overwrites real alpha values.