[magick-users] RE: on destriping again.. low & high pass filter.. how to do pixel algebra in IM

[Fred Weinhaus]

Use -fx, but it is slow or if you have just add, subtract and 
multiply (no division or other more complex factors) you can use 
-compose [plus, minus, multiply] -composite


See

http://www.imagemagick.org/script/fx.php
http://www.imagemagick.org/Usage/transform/#fx
http://www.imagemagick.org/Usage/compose/



>Hello folks,
>
>I found a tutorial which basically uses a low pass filter, a high pass
>filter and an "algebraic" combination of the two to remove striping noise
>from the image... i.e: just random vertical lines due to apparatus defects
>on a satellite board..
>
>I just would like to know how to do pixel algebra in IM... how can I combine
>two images into one by pixel to pixel algebra operations...
>Would it be the convert -combine option?
>
>Any ideas? suggestions?
>
>--
>Mattia