Simulate Photoshop recovery tool

Question

I am interested in processing a bitmap in Java using the same (or similar) technique as the Photoshop Highlighting Tool. (This will be the Image-> Adjustments-> Shadow / Highlight tool in CS4.)

I googled around, and found very little outside the discussion about existing tools that do the job.

Any ideas?

Answer 1

I’m just guessing because I don’t have Photoshop - only from the descriptions that I find on the Internet.

The Radius element is probably used in Gaussian Blur to get the average value around a pixel to determine its selection level or shadow. Shadows will be closer to 0, and highlights will be closer to 255. The exact definition of "close" will be determined using the Tonal Width knob. For example, at 100%, perhaps the shadows come from 0-63, and the main points come from 192-255.

The sum corresponds to the desired change in brightness - again, I do not know the scale or what corresponds to 100%. Changing the brightness of the shadows requires multiplying by a constant value - for example, to increase it by 100%, you need to multiply by 2. You want to scale this according to the shadow value defined above. The main works work similarly, except for working with 255 instead of 0.