Author: JRD
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Color enhancement with the Channel Mixer
RGB Curves, Color Balance, Selective Color, and HSL adjustments are powerful for color processing in Photoshop. A much less-used option is the Channel Mixer in color mode. This is extremely unfortunate as, to my mind, it is the single most powerful adjustment layer for color correction, enhancement, and photorealistic color grading. The channel mixer is…
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16-Bit Luminosity Masks: a mathematical perspective
Pixel-based layer masks in Photoshop can control both where (spatially) and when (conditionally) an adjustment is applied. The most common type of “when” mask is a so-called luminosity mask, using the luminosity information inherent in our image to target application of adjustment effects. For example, if you want to apply a particular adjustment (saturation, brightness,…
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Saturation, Chroma, and Luminosity
In my goal to develop a deeper understanding of color manipulation in Adobe Photoshop—particularly for photographic images—I’ve been working to model Photoshop adjustments and blend modes at a mathematician’s level. Along the way I discovered Desmos, a free and powerful graphing calculator designed for education. Many of the articles I write will make extensive use…
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Welcome to Mapping Light, Shaping Color
I’ve been pursuing landscape and other forms of photography for some time, enjoying both the process of shooting in the field and the technical side of post-processing. Of all aspects of processing, I’ve found color to be the most challenging, and over time I’ve worked to refine a more systematic approach. Given my technical background,…