I have this image from an old website I have to modify.

merged image

I want to change the composition of the image, but this layer is already merged. I found the original background layer from an older source file, but I cannot find the layer with the computers.

I wonder if there is some kind of "comparison" filter that lets you separate the layers where they are different.

original background layer


1 Answer 1


Forget it. If you planned to use some automatic filter to separate the computers and other devices to their own layers one device per a layer you'd need a program which knows those devices and outputs the right images of them from it's stockpile.

Ordinary dumb software like Photoshop knows too little of what our word contains. Photoshop and the others can make comparisons pixel by pixel, but they still do not know very much of our world. The situation has got a little better, programs can recognize where's the border of a common shape like a human head, but knowing the full separate images of even common computer types is too much asked.

Here's what can be got by bit by bit comparison:

enter image description here

Increasing the contrast can make to you a layer mask which separates the devices as a fixed group, but without any possibility to recreate the items separately. The result would be substantially better if you draw a path around the items and make a selection, but that's already suggested by others.

Not the answer you're looking for? Browse other questions tagged or ask your own question.