Creates transparent overlays from pasted images or the result of a filter operation.
This ImageJ plugin filter applies an Alpha Channel immediately after a paste or filter operation. The output is a blend of the original and the result of the filter/paste operation preceding the call of this plugin, with the weight of the filtered/pasted image given by an 'alpha channel' image.
After running 'Alpha Channel', what looks like a transparent overlay is actually part of the image and not a separate layer!
The alpha channel can be modified before applying it: