Pixiq

I developed the PercepTool as a result of years of research in lightness perception. This tool basically takes the flat 2-D image we get from the camera and makes it into an image that mimics closely the perception of the human brain. The PercepTool plugin is available for download from my website, www.georgedewolfe.com. When you download the plugin, specific instructions for installing are included.

Because of the nature of Photoshop, the sliders will seem jumpy, as I have chosen to work around a proxy preview in a dialog box and give you a real time preview in the main window where the real image is. In this particular scenario, the Photoshop software developer kit does not allow us to both update the image immediately while also sliding the sliders, so the effect appears jumpy. This is normal because of the way Photoshop works. The big advantage here is that it works in 32 bits (as well as 8 and 16 bits) and you get a correct preview as you are working, which is extremely important for work with the PercepTool.

Here’s how the PercepTool works:

1. With the image you are working on open in Photoshop, go to File > Scripts > PercepTool.

2. When the PercepTool interface appears, the defaults will be Perceptual Effect: 50, Gamma: 1.0, Saturation: 100.

3. Adjust the Perceptual Effect slider first. For most images, 65 to 90 will be enough. You will see more of a change in low and middle key images than in high key ones. The Perceptual Effect tool is the main function of this plugin; it mimics closely how the brain interprets what the eye sends to it.

4. Adjust the Gamma slider second. I’ve found that a Gamma of .75 – 1.0 seems to work the best for most images.

5. A Saturation slider is included, but it’s not necessary for black-and-white images so set the slider to 0.