CompuServe Messages

Regarding a difference "matte" (scene shot with and without character – goal is to extract the character). First – doing these video conversions is hard work. I've done some down to 16 colors. It just takes work in my opinion. One idea to elimiate jitter in a background is to pick a background you like, put it on the swap buffer, use a gross mask around the foreground object, and use the scrape ink. (There's a way to make a mask move overtime, but it escapes me at the moment. Oh, I think it has to do with compositing flics [time to brew some coffee <grin>].) Now, back on track. A difference matte. If there wasn't pixel drift, you could apply the MINUS ink – pixels in the same color would go to zero (color slot number) and you could use the non-zero pixels (inverted?) as a mask to pull out the character. How would this work if the colors don't match? It would work better if you could sort the palette so that the colors of the background are clustered and the colors of the character are clustered. Then the MINUS ink would give you colors near zero. Not perfect, but perhaps a step in the right direction. You could use the "logical" AND/OR/XOR inks in the same way, think about it. Other inks you should look into working with are SWEEP (to clean up single pixels), and HOLLOW (to give you outlines). Chuck Jameson Silver Tongue Software