1. The Physics of Optical Sensor Binarization
Camera sensors do not read color; their CMOS image sensors capture luminance (grayscale intensity). The decoding software applies an adaptive thresholding algorithm (such as Otsu's binarization method or Bradley local thresholding) to partition each pixel into a binary `0` (light) or `1` (dark).To achieve reliable binarization across diverse lighting conditions: * Minimum Luminance Contrast Ratio: The relative luminance contrast between the foreground modules and background substrate must exceed 4.0:1 (ISO recommends > 7.0:1 for commercial production). * Color Pairing Guidelines: * Safe Pairs: Black on white, dark navy on white, deep forest green on pale yellow, charcoal on cream. * Dangerous Pairs (High Failure Rate): Red on white (red wavelengths appear bright white to monochrome sensors), yellow on white, gray on silver, orange on wood.