There's also the X Bitmap format: https://en.wikipedia.org/wiki/X_BitMap https://en.wikipedia.org/wiki/X_BitMap GIMP outputs it, which means you can make much

There's also the X Bitmap format: https://en.wikipedia.org/wiki/X_BitMap https://en.wikipedia.org/wiki/X_BitMap GIMP outputs it, which means you can make much any image embeddable into a C source.