Can use millions of colors. Best for photographic or painted images. You can specify amount of file compression. Relies more on processor speed of client computer. XBM X bitmap format.
Files normally have .xbm suffix.
Uses only 2 colors. Release the mouse. Move the mouse inside your chosen picture. When the cursor turns into a pair of scissors, press the return key and the unwanted portion of the picture is cropped out. Watch the proportions in the title bar.