Aligning multiple images in photoshop

We want images stacked

Sometimes we capture images of the same area (e.g. a particular part of a thin section) using different conditions (reflected light, PPL, XPL, Cathodoluminescence) . We may then want to stack the images together so that we can see how each different mineral, for instance, appears under the different conditions.

THE PROBLEM

We can align objects manually because we see recognisable features in each image. It can be a little tedious and difficult trying to add, manually align, resize and rotate the images in software like: Adobe Illustrator, photoshop, the gimp, image j or other software.

There is a semi-automated way to speed up this process in photoshop. I’m not sure of the exact conditions under which this will actually work. But it’s fairly easy to try and could save you a load of time.

How to do it

The first thing we need to do is to load all the images as layers in a photoshop document.

• Open photoshop
• Go to file>Scripts>Load files into Stack

• Navigate to the folder with your images in it and load these.

You should now see all your images as layers in photoshop with names corresponding to file names (handy eh?).

• Select all the layers by clicking on the top layer and then shift clicking on the bottom layer. They should all have a blue background in the layers panel indicating they are all selected.
• Now go to edit>auto-align layers
• I recommend trying collage first which will not distort the image.

Thanks to Steve Kidder for working this out with me.