No-reference banding detector

A small, self-contained Python script that finds banding (false contouring) in a single frame without a reference image. It locates smooth, low-texture regions (where banding lives) and scores the low-amplitude, isolated steps inside them — the BBAND/CAMBI idea, simplified: a contour is a small step flanked by flat plateaus, weighted by how visible it is at the local brightness. Works on live and UGC where no original exists. Includes a built-in --demo self-test that separates a clean 10-bit-sty