I invented PercepTool™ to solve the problems mentioned in B&W Printing, 2009, published by Lark Publications. Basically, the tool works with the luminance image we get from the camera and corrects it to look like the luminosity percept produced by the visual cortex of the brain.
The idea behind PercepTool™ originated in 1978 with Ed Land’s essay (see page 21 in the book) and continues with my ongoing research in lightness perception. At this point it is nearly impossible to create this percept effect manually in Photoshop. So, I set out to make a Photoshop plugin that would accomplish this difficult task with the most sophisticated tools available to us in digital imaging science. In the software, one click changes the luminance image into the luminosity percept of the visual cortex. For those of you making that one click, remember that the development time and research involved behind that click took 30 years. PercepTool™ is used in combination with one or two other Photoshop tools, most notably the Gradient Map. There are two basic ways to apply PercepTool™: 1) Apply the Plugin alone without the script. This can be done in Photoshop CS4 standard and extended versions in 8, 16 and 32 bit modes. The script version can be run in 8 and 16 bit mode in Standard Photoshop CS4 and in 32 bit mode in Photoshop CS4 Extended. The reason for the script operating only in the extended version has to do with limited support for Layers in 32 bit mode in the standard version.
How does PercepTool work?
PercepTool takes the image made in the digital camera
sensor (also called luminance image) and changes it into what
our brain actually perceives. The luminance image consists of 2 sub
(intrinsic) images: reflection and illumination. The
reflection and illumination images are separated from the luminance
image in the visual cortex of the brain, processed and recombined into
what is known as the percept, or the image that we actually
perceive. We call this image luminosity. Most of the changes
are due to differential recombination of the edges in the image and
optimization of tonal values.
Here is a demonstration of the process:
PLEASE READ BEFORE PURCHASING OR DOWNLOADING TRIAL
NOTE TO WINDOWS VISTA USERS: you may experience installation or operation problems if you download your files with Firefox. Internet Explorer is a good option.
System requirements: Perceptool is now available for both Windows XP and
Vista and Macintosh Intel. For those of you who have Photoshop Standard,
the script works in 8 and 16 bits per channel and in Photoshop Extended
in 32, 16, and 8 bits per channel. The
main reason for this discrepancy is that layers are not totally supported in
Standard in 32 bits per channel, required by the scripts. The no-UI Filter plugin
works always at 100% and works in 32 bits per channel on all versions. There
is no
64 bit version for Vista 64.
Purchase: When you click on the word "purchase" above to purchase the PercepTool you will be taken to a special shopping cart separate from the one you use to purchase other student supplies or prints from this site. If you are making purchases of other products from this site you will have to order and pay for them seperately from your PercepTool download.
Free Trial: To download a free trial, click on the words "free trial" above and the download will start automatically. You don't have to go to the shopping cart for the trial download.
Note: An unfortunate misprint in my book B&W Printing, listed the price of the PercepTool incorrectly.