Thanks to consistent help,
I am inching closer to the goal.
Attached patch is crude background subtract
that saves sequence of Pngs
using count to increment filenames.
Result:PNG has a black background.
Desired Result: transparent background.
OS : Windows XP, Jitter 1.2.2
I think it is simply a problem with syntax I am sending to exportimage.I am concatinating strings using sprintf and sending "exportimage filename.png png-24 lossless"
How do i specify preserve alpha?