This is a curious tip that I’m providing more as a FYI than a claim that it might enhance your workflow.
First, the basics. All OS X files can contain icons that appear in Finder listings/on the Desktop — from the simplest text document to folders to apps. This is possible because of how the OS X file system works (google “OS X resource fork” for more info).
In a folder full of pictures, or on the desktop, Finder will automatically generate thumbnail previews for all image files. But these aren’t actually genuine icons for the files. It’s just a trick performed by Finder.
You can give each image file its own icon, generated from the image itself, by opening Terminal (it’s in the Utilities folder of the Applications list in Finder), and typing the following:
… followed by a space, then clicking and dragging the folder full of pictures over the Terminal window. However, don’t release the mouse button until you’ve first held down Command. This will switch Terminal into the directory automatically.
Then type the following into the Terminal window.
sips -i *
Nothing will appear to have happened but if you click on the Finder window, then open the View Options dialog (Cmd+J) and uncheck Show Icon Preview, you’ll see that the images are still thumbnails because now you’re looking at the image’s icons.
I can’t really think how this can be useful on a modern Mac with lots of RAM and a fast CPU, but if you have a folder full of hundreds or thousands of images then this trick plus deactivating icon previews might make it easier to browse through them.
Be aware that the icon won’t change if you edit the image in any way, until you use the sips -i command again.
The sips command is actually pretty cool and can do all kinds of things to images at the command-line. Check out its man page for more info.