Value Mirror

Value Mirror is a value study tool for painters and drawing artists. Convert any photo or live camera feed to grayscale, group tones into clear tonal masses, and read light and shadow structure without color getting in the way.
Inspired by the Claude glass — a black mirror used by painters for centuries to compress tonal range — Value Mirror brings the same technique to any image, instantly.
What artists use it for:

Simplifying reference photos into 2–10 tonal masses before painting
Squinting digitally — blur away detail to see only the big shapes
Notan studies — reduce any image to pure light and dark groupings
Checking light and shadow grouping across a composition
Identifying lost and found edges
Proportion checking with instant horizontal and vertical flip
Grayscale reference for oil, watercolor, and digital painting

Key features:

Value massing — group your image into 2 to 10 tones
Squint mode — progressive blur reveals major value shapes
Edge detection — find structural boundaries
Value isolation — highlight one tone at a time
Compare mode — measure lighter or darker between two points
Grid overlay — proportion reference
Live camera — analyze your subject in real time
Save studies as high-resolution images
Works offline — installable PWA

Who it's for:
Painters, illustrators, and drawing students who work from life or photo reference and want to read tonal structure accurately. Especially useful for anyone practicing Notan, value massing, or classical atelier methods.