I'm trying to write an 8-bit Windows icon whose pixels are fully transparent if the corresponding pixel in the 32-bit RGBA source image is fully transparent. I realize that transparency in 8-bit Windows icons is not handled by defining one of the 256 colors to be treated as transparent (like e.g. the GIF format does) but by a matte / AND mask that is stored in addition to the pixel data. While from looking at icon.c it seems it is able to write the mask, I did not yet succeed to call convert in a way that for a source alpha value == 0 a mask value of 0x00 is written, and for a source alpha value != 0 a mask value of 0xff is written. Any hints on how to do that?
PS: Back in this thread I was still thinking that Windows icon transparency is achieved by palette index transparency, which is wrong, see above.
Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
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