A reader recently asked me for a way to automatically create thumbnail icons for image files copied to the hard drive. It turns out that Mac OS X includes a nifty Folder Action script that you can attach to a folder so that any new image added to that folder will automatically have just such a thumbnail added. However, there are situations in which Folder Actions aren’t the best approach. Another solution—and one that offers many more options—is Sven Janssen’s CocoThumbx 3.1 ( ; payment requested).
Just drag an image or a group of images—in BMP, EPS, GIF, ICNS, JP2, JPG, PDF, PICT, PNG, SGI, TARGA, or TIFF format—to the CocoThumbX window and the app will create a 128- by 128-pixel thumbnail icon for each file and automatically embed it in the file’s resource fork.
CocoThumbX’s basic thumbnail options, accessible via the “back” of the window—the application’s window looks and behaves much like a Dashboard widget—let you customize the resulting thumbnail icons with a drop shadow, an iLife-like “reflection,” rounded corners, and/or a border. Although the options are straightforward, I do have two minor complaints here. First, it would be helpful if CocoThumbX provided a sample image to preview what each option will do. Second, if you’ve set CocoThumbX to Remove Thumbnail mode, these options still appear but you can’t change any settings; you have to switch back to Add Thumbnail mode. I found this a bit confusing.
If you decide you want to re-process a batch of files using different settings, the File: Repeat Last Files command does just that. You can also use CocoThumbX to remove thumbnails from image files, and the utility has a plethora of additional options accessible via its preferences dialog; for example, you can even create representative thumbnails for Word, RTF, RTFD, HTML, CSS, plain text, and QuickTime-supported-movie files. Finally, a “folder-watch” feature, currently in beta, works much like OS X’s Folder Actions—except that you get all the additional features of CocoThumbX when creating thumbnails.
If you want to use thumbnail images on a Web page or as icons for another file or application, CocoThumbX can instead save each image’s thumbnail to a separate folder as either a new image file or as an ICNS file.
CocoThumbX also comes with a handy plugin for Mac OS X’s Services menu; after installing it (in ~/Library/Services or /Library/Services) and restarting the Finder (or logging out and back in), you simply select images files in the Finder and then choose Finder: Services: CocoThumbX : Create Custom Icon (or press Shift+Command+S) and thumbnail icons will be added to the files using the current CocoThumbX settings. There’s also a services option for removing custom icons.
CocoThumbX requires Mac OS X 10.4 or higher and QuickTime 7 or higher; it is a Universal binary.