Complex sentence: Note that many other image handling applications do not support a color palette of an arbitrary number of colors; if, for example, you reduce an image to 13 colors via ImageMagick some applications will open it but some will regard it as corrupted.
Split into simpler sentences: Note that many other image handling applications do not support a color palette of an arbitrary number of colors. If, for example, one reduces an image to 13 colors via ImageMagick, some applications will open it but some will regard it as corrupted.