I created a new effect in RNOEffects for this. There's now the "Opacity map" effect, which can be used to create an opacity map image (a grayscale image describing the transparency level) from the alpha channel of the loaded image. You can also apply such a map back to an image to add transparency.

So, to batch convert loads of files, open the Opacity map effect window, leave it in the "Create image" mode, and add files in the Batch convert window and start the conversion process.

Here's a "test" executable, which can be copied over the previous installation: RNOEffects exe


[ Edited by jPV 03.11.2021 - 19:18 ]