Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

binary image

An image with exactly two legal pixel values.

A binary image has exactly two legal pixel values, conventionally $0$ (background) and $1$ or $255$ (foreground) -- the output of thresholding and the input to morphological operations.