Cutting pieces out of an image using a pattern contained in another image using GIMP

Question

Imagine a simple photo. Say, a black and white portrait of someone. I want to create a special effect with this photo. The middle of the photo will remain unchanged, but as we move further from the centre, there are pieces missing and the background is white. Near the very edges of the photo, there are mainly white areas.

One idea I had was to create an image of the "cutting pattern" and somehow cut the photo with this other image. My question is, can that be done in GIMP and if so, what is the step-by-step procedure for doing that?

As an example of what I am trying to do, I have attached two images. The first image is a photo of John Lennon. The second is a white image with many black squares. It has the same dimensions as the first.

What I want to do is use the black squares in the first image, and cut those areas out in the second, leaving those areas in the first image transparent.

Answer 1

You can use a layer mask to do that.

1. Open the image of John Lennon in GIMP.

2. Open the image of the squares. Do Select > All and then Edit > Copy

3. Back in the John Lennon image, hit the "Add a mask" button in the layers panel, then in the dialog that appears, hit "Add".

4. Do Edit > Paste, and hit the Anchor button in the layers panel. This will anchor the Floating Selection to the mask.

Note that in GIMP, transparency is indicated by a checkerboard pattern. If you were to put a layer below the John Lennon layer, the image on the layer below would show through the mask.

Here's an example