Possibility/plans to write GIFs with an alpha layer ?

[Zulko]

I have seen in the docs that it is not possible right now, and I played a little bit with it but it is still unclear to me if it is a limitation of freeimage, or just not implemented yet.

[almarklein]

Looked into it again, and it seems to be a limitation of freeimage; the quantize functions only accepts 24bit images.

From the looks of it, it would not be possible to provide a full range of alpha values. However, the following may be a feasible workaround:

• in Python, map all pixels for which alpha < 50% to a specific color (preferably a color that is far away from any other color in the image)
• Turn the image to RGB (by discarding the alpha channel)
• Quantize this 24 bit image
• Set the specific color to be fully transparent.

[almarklein]

We should try again with Pillows gif writer.

[almarklein]

I tried with Pillow, but it keeps producing RGB palettes instead of RGBA. I spend more time on than this ancient format is worth :) So from my end this is a wontfix. (Though I am open for PR's that address this issue.)

[almarklein]

Maybe via #220

[FirefoxMetzger]

Closed in favor of #360 .

The original question for free-image, which doesn't support alpha/transparency in GIF, this issue has been identified as a won't fix. If there is a particular need to support transparent GIF via free-image, please create a new issue that can be titled and tagged appropriately.