By Lesa Snider Macworld.com | on August 17, 2009
Price When Reviewed: 56
Pros: Easy to use interface when run as a script; instantly adds life to flat images.
Cons: Difficult to use as a plug-in filter.
Can a single click really represent 30 years of research and hard work? Professional photographer George DeWolfe certainly thinks so -- his PercepTool plug-in for Photoshop CS3 and CS4 attempts to mimic your visual cortex in order to make an image look the way your brain thinks it should. In one fell swoop, this plug-in alters the brightness, edges, and contrast of your images.
It’s targeted to professional photographers and anyone else interested in producing the greatest depth possible in their colour or black and white images. The most recent update gives users a welcome speed boost over previous versions of the plug-in.
Installation is a manual affair, though easy enough; just drop the plug-in and script files into their respective folders inside the Photoshop CS3 or CS4 application folder and then relaunch Photoshop. Either way, you’ll want to read and follow the recommended workflow that’s been carefully laid out in the plug-in’s accompanying PDF.
PercepTool isn’t a 'fix all' solution—it’s meant to be used after your regular global and local adjustments to make your image pop; if Apple’s Aperture, Adobe Photoshop Lightroom or Camera Raw is part of your workflow, you should optimize your image there first and then open it in Photoshop and run PercepTool. For the best results, be sure to correct clipped highlights in those programs first, as they represent areas whose color values have been pushed to 100 per cent. Since clipped highlights are stripped of detail, PercepTool has very little chance, if any, to make those areas look better.
Pro photographers who use Photoshop Extended will appreciate the ability to edit 32-bit RGB images. Standard users can edit 8- or 16-bit RGB or Lab images (Lab mode cannot be used on 32-bit images).
You can use PercepTool in a couple of different ways: as a script or a plug-in. To run it as a script, choose File > Scripts > PercepTool and it instantly duplicates your original layer and opens a friendly dialog box appears containing three sliders in the order in which they are to be used: Perceptual Effect, Gamma, and Saturation. For black and white images, you need only adjust the first one, but for color images you’ll use all three.
The Perceptual Effect slider is where the real magic happens, as it takes an image and uses a series of complicated algorithms (affecting both the image’s brightness and edges) to mimic what happens in the visual center of your brain. Without getting too technical, the images we “see” are different from the images captured by our eyes or camera sensor—the brain applies another process to the image that results in the image we actually perceive (hence the plug-in’s name). The end result is an image with increased depth and tonal range, which more closely resembles the one we thought we saw in the first place.