This utility node blends two floats / colours together using a blending mode. A complete reference for the blend modes and how they behave is well explained in this reference.
...
Mode | |
---|---|
Over | Result = Foreground Background is ignored in this blend mode. |
Multiply | Result = Background * Foreground Multiply blend mode multiplies the numbers for each pixel of the top layer with the corresponding pixel for the bottom layer. The result is a darker picture. This mode is symmetric: exchanging two layers does not change the result. |
Screen | Result = 1 - ( (1-Foreground) * (1-Background) ) With Screen blend mode the values of the pixels in the two layers are inverted, multiplied, and then inverted again. This yields the opposite effect to multiply. The result is a brighter picture. This mode is symmetric: exchanging two layers does not change the result. |
Darken | Result = least bright of Background and Foreground |
Lighten | Result = brightest of Background and Foreground |
Color Burn | Result = 1 - ( 1 - Background ) / Foreground) |
Color Dodge | Result = Background / ( 1 - Foreground ) |
Divide | Result = Background / Foreground |
Saturation | Result = Saturation of Foreground applied to Background colour |
Luminosity | Result = Luminosity of Foreground applied to Background colour |
Hue | Result = Hue of Foreground applied to Background colour |
Difference | Result = Absolute( Background - Foreground ) |
Substract | Result = Background - Foreground |
Add | Result = Background + Foreground |
AddSub | Result = Add if luminance of Background is greater than 0.5, Substract otherwise. |
...