Posted: 2006-10-22T18:40:16-07:00
A better method of adding extra masking in Alpha Compositin is to use the correct compose method.
As mask already has alpha, use it.
the above finds that parts of Alpha that falls within the non-transparent areas of the overlay mask image. if you want the reverse use 'Dst_Out' instead.
see IM Examples, Alpha Composition for more details.
http://www.cit.gu.edu.au/~anthony/graph ... ose/#dstin
You do not need to extract and mathematically merge the masks.
As mask already has alpha, use it.
Code: Select all
composite Mask.rgb Alpha.rgb -compose Dst_In alpha_masked.rgb
see IM Examples, Alpha Composition for more details.
http://www.cit.gu.edu.au/~anthony/graph ... ose/#dstin
You do not need to extract and mathematically merge the masks.