Aaaa... Am I missing something... it IS late at night & I am a bit wuzzy, but... Starfield on a black background? Just do a gross sort of selection of the areas that you don't want and then past the remainder into a new layer in the 'Screen' mode. The stars will remain, but the black background will disappear. This will work only if the background is a perfect RGB 'black'. Actually the night sky is not perfectly black, but somewhere in the range of R-15 G-25 B-45, for a very dark blue. Good night... I need to pass out now...