The IlvComposeFilter Class
The IlvComposeFilter class lets you perform the combination of the two input images pixel-wise in image space using one of the Porter-Duff compositing operations: over, in, atop, out, xor. Additionally, a component-wise arithmetic operation (with the result clamped between [0..1]) can be applied. You have a choice of these six operators for the compositing, shown in Compositing Operators.
The resulting color is given by the formula:
Cresult = Fa * Ca + Fb * Cb
where:
Ca is the color from the first image, and Cb is the color from the second image.In the table, Aa is the alpha value from the first image and Ab is the alpha value from the second image.Operator | Operation |
|---|---|
over | Fa = 1, Fb = 1 - Aa |
in | Fa = Ab, Fb = 0 |
out | Fa = 1 - Ab, Fb = 0 |
atop | Fa = Ab, Fb = 1 - Aa |
xor | 1 - Ab, Fb = a - Aa |
arithmetic | Cresult = k1 * Ca * Cb + k2 * Ca + k3 * Ca * Cb + k4 |
Published date: 05/24/2022
Last modified date: 02/24/2022
