Duff-Porter Alpha-Compositing Operators

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image α
object α
Duff–Porter compositing operator
object "over" image
resultant α-channel as thumbnail
In image alpha-compositing, the Duff–Porter operators are a standard set of 12 rules for determining the RGB
α
values of each output pixel as a function of the RGB
α
values of two corresponding input pixels. In this Demonstration an image of a spiral staircase (the "object") is composited with a background image of a tiger (the "image"). The default object "over" image compositing method corresponds to the usual application of alpha blending to semi-transparent foreground objects. Different compositing methods produce other interesting effects.

Permanent Citation

Andrew Moylan
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​"Duff-Porter Alpha-Compositing Operators"​
​http://demonstrations.wolfram.com/DuffPorterAlphaCompositingOperators/​
​Wolfram Demonstrations Project​
​Published: March 7, 2011