What EXACTLY does the "Xor" blending mode do?

[Scantron]

The official documentation on this mode is frustratingly vague:

• "This is short for "exclusive OR", which is an advanced blending mode that is primarily used for image analysis and not for drawing or image composition."

Thing is, I do personally use it to make art. I think if I knew what exactly it did, I could more easily create images that have eye-pleasing results when blended together using xor.

 

Any help or information you can give is appreciated!

[pdnnoob]

http://www.mushclient.com/mushclient/mw_blending5.htm#blend33

XOR basically means "x or y, but not both." When the two pixel values being compared are the same, you get 000000 (black), and when they are opposites, you get FFFFFF (white). Things in between vary based on how different the pixel values are from each other.

@Anonymous If you don't have anything useful to say, don't post.

[midora]

As pdnnob told it is and exclusive or operation on bitlevel.

 

So for each bit N in the 24 bit RGB triple

    compositeBitN = layer1BitN ^ layer2BitN  (0^0=0, 1^0=1, 0^1=1, 1^1=0)

Alpha handling is more complex. So I would use opaque layers only.

[Rick Brewster]

This is EXACTLY what it does: http://lmgtfy.com/?q=xor

 

[Rick Brewster]

Alpha handling is more complex. So I would use opaque layers only.

 

Alpha is handled the same regardless of blending mode. Only the treatment of the color channels is affected by your choice of blending mode.

[Goonfella]

Interesting. Always wondered about that myself. I just thought it was just another blend mode.

[Scantron]

Thanks for the help!