Algorithm for Hue/Saturation Adjustment Layer from Photoshop

Question

Does anyone know how adjustment layers work in Photoshop? I need to generate a result image having a source image and HSL values from Hue/Saturation adjustment layer. Conversion

Answer 1

Hello I wrote colorize shader and my equation is as folows

inputRGB is the source image which should be in monochrome

(r+g+b) * 0.333

colorRGB is your destination color
finalRGB is the result

pseudo code:

finalRGB = inputRGB * (colorRGB + inputRGB * 0.5);

I think it's fast and efficient