Tag: photoshop

  • 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,…

  • 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…