I would like to save an image (PNG or BMP) to disk based on data that I have in a sparse matrix. (There are only a handful of pixels that I need to paint, even though the total image size may be large.) Ideally, the image would be able to have transparency, but I can live without. I'm not sure if this is the correct approach, but I've created a dummy GUI with a graphics object, and painted some of the pixels using something like the following: $Graphic = GUICtrlCreateGraphic (0,0,100,100) GUIC