: Can Animated GIFs be reduced in filesize by comparing regions that actually changed? Can GIFs be optimized so that only the changed regions (pixels within certain rectangular bounds per frame)

@RJPawlick971

I'm guessing this is the case


actually, no, that's not the case. Animated GIFs are optimized in exactly this way...each frame only contains the parts of the image that actually changed from the previous frame.

Wikipedia doesn't go deep into detail, but does mention it here:


Some economy of data is possible where a frame need only rewrite a portion of the pixels of the display, because the Image Descriptor can define a smaller rectangle to be rescanned instead of the whole image.

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@Barnes313

Yes, GIF files can be optimized in that way. This reduces the size of the individual frames, and thus the overall file size.

Your image manipulation application might offer this; for example the Animation Optimize filters for GIMP do that: docs.gimp.org/2.8/en/plug-in-optimize.html

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