I have 3 images, and 3 alpha images of those images. Now I want to compose them so you can see 3 parts of those images in one image, with the help of the alpha images.
How can I do that?
I have 2 images in .tga and RGBA. How can I compose these images using the alpha channel of the targa file.
I have taken a look at the documentation, but I can’t find much more than masks for compositing images. But it’s impossible to make a mask from the images since they are anti-aliased. So when compositing they leave artifacts.
Indeed, I think you should load the alphas as selections (Select>Load>Selection), then copy and paste in a new image. You could also use layer masks, which are a little more complicated:
With the 3 images in separate layers, select one layer, load the corresponding alpha as a selection, and go to Layer>Add layer mask>reveal selected. The layer will then be masked, and the layer palette will the show the thumbnail, a little chain and the mask. If you want to move or edit the mask, click on the chain icon and then on the mask icon.
If the antialiased images have an alpha channel, I think these should be antialiased too. Load the alphas as selections.
From what I understand of your questions, I hope that helps.