Hello folks,I am trying to get the Add and Subtract blending mode (similar to what we get via apply image in photoshop) in Nuke so I can produce a highpass and lowpass separation. I used the blur node and merge in minus mode to get the high pass and low pass but the result is not as delicate and detailed as what I get from photoshop apply image command. I believe it has to to with being able to set the offset and scale in apply image. I found the following guide regarding how the Add and Subtract mode works in photoshop. I would appreciate if you guys can help me to get the python code needed for it (or if there's another way of doing it).
thanks a lot,
Add
Adds the pixel values in two channels. This is a good way to combine non-overlapping images in two channels.
Because higher pixel values represent lighter colors, adding channels with overlapping pixels lightens the image. Black areas in both channels remain black (0 + 0 = 0). White in either channel results in white (255 + any value = 255 or greater).
Add mode divides the sum of the pixel values by the Scale amount, and then adds the Offset value to the sum. For example, to find the average of the pixels in two channels, add them, divide by 2, and enter no Offset value.
The Scale factor may be any number between 1.000 and 2.000. Entering a higher Scale value darkens the image.
The Offset value lets you lighten or darken the pixels in the destination channel by any brightness value between +255 and –255. Negative values darken the image; positive values lighten the image.
Subtract
Subtracts the pixel values in the source channel from the corresponding pixels in the target channel. As with Add mode, the result is then divided by the Scale factor and added to the Offset value.
The Scale factor may be any number between 1.000 and 2.000. The Offset value lets you lighten or darken the pixels in the destination channel by any brightness value between +255 and –255.