Photoshop CC: The Missing Manual, 2nd Edition

Auto-Aligning Layers and Photomerge

If you’ve ever needed to combine a few group shots to get an image where everybody is smiling and their eyes are open, you’ll appreciate the Auto-Align Layers command. Sure, you can manually align layers (using the Difference blend mode; Composite Blend Modes), but when you run this command, Photoshop does all the hard work for you by examining the active layers and aligning them so identical areas overlap (see Figure 7-20).

Figure 7-20. The Auto-Align Layers command is great for merging a few imperfect shots into one perfect image (or at least one where each subject is smiling). To do that, combine the images into one document and place the non-smiling layer (left) above the smiling layer (right). Then run the Auto-Align layers command. Finally, add a layer mask to the top layer and then paint the non-smile away with a black brush so your smiling pal shows through from the layer below!

Once you’ve arranged your images on different layers in the same document—they need to be exactly the same size or pixel dimensions—activate at least two layers by Shift- or ⌘-clicking them (Ctrl-clicking on a PC) in the Layers panel. Next, choose Edit→Auto-Align Layers (this menu item is dimmed unless you have two or more layers activated). In the resulting dialog box, choose an alignment method:

• Auto. If you’re not sure which method will work best to align your images, ...