color-to-alpha
This replaces as much of a given color as possible in each pixel with a corresponding amount of alpha, then readjusts the color accordingly.
(nothing selected)
Move the mouse over the right image to select a color, click to (un)lock the current selection.
Move the mouse over the right image to select a color, click to (un)lock the current selection.
— Original implementation by Seth Burgess <sjburges@gimp.org> for the GNU Image Manipulation Program. 7th Aug 1999
Image by Spinning Spark on Wikimedia Commons.
