Image Filter
Intensity = (R + G + B) / 3
YCbCr
Y = 0.2126*R + 0.7152*G + 0.0722*B
o
Blend mode
- https://en.wikipedia.org/wiki/Blend_modes
Here color is between 0.0(black) and 1.0(white).
Normal
\[f(a, b) = b\]Dissolve
\[\]Multiply
\[f(a, b) = ab\]Screen
\[f(a, b) = 1 - (1 - a)(1 - b)\]Overlay
\[f(a, b) = \begin{cases} 2ab & a < 0.5 \\ 1 - 2(1 - a)(1 - b) & a >= 0.5 \end{cases}\]Hard Light
Soft Light
Dodge and burn
Divide
Addition
Subtract
Difference
Darken Only
Lighten Only
Alpha channel
\[\]Reference
- https://dunnbypaul.net/blends/
- https://stackoverflow.com/questions/15007304/histogram-equalization-not-working-on-color-image-opencv