A version of this tutorial first appeared in an issue of Photoshop Fix
Photoshop’s Displace filter don’t get no respect. It doesn’t have a flashy preview window, it’s unintuitive, and can’t even work by itself, needing a 2nd image to tell it what to do. But this under-appreciated filter could save your career. We’re going to use the Displace filter to unobtrusively watermark photos in such a way so that not even the most patient thief could retouch out your proof of ownership.
The Displace filter moves (or displaces) pixels horizontally and vertically, up to 128 pixels. By itself that sounds rather unimpressive, but it references a second image, called a displacement map, to determine how far to move the pixels. The tonal values of the displacement map, from 0 to 255, control the degree of displacement. A value of 0 (white) will displace the image 128 pixels up and left. A value of 255 (black) will displace the image 128 pixels down and right. A value of 128 (50% gray) won’t displace anything at all.
1 Make a new RGB document, 100px tall and 400px wide. Select Edit > Fill > 50% Gray (remember, the Displace filter ignores gray). With the Type tool set to black, type in the text of the watermark. This image is from LiquidLibrary, so that’s our text, and I used 36pt Helvetica. Now flatten the image and use Filter > Stylize > Emboss set to minimum height and 100%. Save as WATERMARK.PSD and close the file.
2 Open the image you’d like to watermark. Make sure it’s a backup copy, since this will make permanent changes.
3 Run Filter > Distort > Displace. The Displace dialog lets you modify the effect of the displacement map, from 0% up to plus or minus 100%. It also lets you choose whether to stretch your map to fill the entire image (handy for logos) or tile it. We’re going to use tile. Finally, it asks whether to pad undefined areas (blank areas) by repeating or wrap them to the opposite side. We’re not going to have any undefined areas, but I usually set this to wrap. Click on OK and it will ask you for a displacement map. Point it to WATERMARK.PSD that we made in step 1 and click OK.
4 You can record step 3 as an action to use with File > Automate > Batch and watermark an entire folder of images. Just make sure to choose different Source and Destination folders.
5 Can’t see any apparent difference in the image? That’s the idea, it looks virtually the same unless you zoom in. Then you have a hundred little watermarks protecting your ownership of your images.
If you want to experiment further with displacement maps, Photoshop comes with a dozen in the Plug-Ins\Displacement Maps folder.