Once you apply the mask, the layer is rendered and the unseen image data is thrown away. I reckon that without advanced pixel-based scripting, this is not possible within Photoshop.īased upon the answers given and your comments, the short answer is: you can't do what you want. Is anyone smarter than me and can create this? In the last step, I 'unflattened' the layer by double-clicking, and created a layer mask using the alpha-layer from the original image, resulting in this:Īs stated above, this doesn't create an un-premultiplied image, as my example would have to look like this to be un-premultiplied: I then pasted the R-G-B layers I had created into the corresponding channels in the new image: Then i created a new image with the same dimensions and without transparency. I also extracted the transparency of the original image into a layer by command-clicking on the layer-thumbnail and filling a new layer with the selection. The channel view in PS looks like this:īy selecting the individual channels I copied them into individual layers, then flattened them with a white background to recieve a black and white map as shown here:
I want to know how to go from State B to State A. so - to go from state A to State B, one simply has to apply the layer mask.
IMPORTANT: the layer is just for this example fully constant red - but you could think of any arbitrary image instead of the constant red.
I hope you understand the problem and can give me a solution to it. I can't just underlie the transparent layer with black, take the selection from it as a mask and merge the layers, because this would result in the alpha being premultiplied in the RGB values. the result should look the same as the original. Now I want to transform this to an opaque layer (just unpremultiplied RGB) + a alpha mask.
I have a transparent layer in Photoshop CS5 (so internally, it's most probably stored as unpremultiplied RGB component plus an alpha component per pixel).