Talk:Alpha compositing

The illustrations in the description section
This regards the blue and orange shapes in the illustrations of the Description section.

While it might be simple to understand for many people, it could be helpful to novices if the A and B colors and shapes were clearly identified. For example:
 * Note that in the illustrations below:
 * A is the blue square
 * B is the orange circle

A legend might also serve the purpose.

Also, the row headers could be simplified:
 * Opaque shapes
 * Partially (50%?) transparent shapes

Thoughts? Dawnvawn (talk) 22:56, 16 January 2024 (UTC)

GIF, BMP
"GIF supports alpha channels". This claim should have a reference. No software I know of allows to save an alpha channel into GIF. This format only has a single color transparency where a palette color can completely transparent. It is possible to overlay another layer on a GIF to extend the palette, but the top layer again can only be completely opaque or transparent. This mode is almost never referred to as alpha. I think the remark about effiency needs to go. Especially in a list next to TIFF.

"The file format BMP generally does not support this channel". Perhaps it more correct to say that some or most [quantify?] software doesn't support this. The primary use for the BMP format is within Microsoft Windows GUI. It supports transparent bitmaps in dialogs like an About box since Windows 2000 or XP (unsure which). You can have a 32-bit bitmap fade to any window color (with the side effect of a memory leak).

TARGA is one of the oldest commonly used formats with true alpha (not just 1-bit), predating PNG and BMP. -- J7n (talk) 16:53, 6 May 2024 (UTC)