corridorkey-green-screen

SKILL.md

CorridorKey Green Screen Keying

Skill by ara.so — Daily 2026 Skills collection.

CorridorKey is a neural network that solves the color unmixing problem in green screen footage. For every pixel — including semi-transparent ones from motion blur, hair, or out-of-focus edges — it predicts the true straight (un-premultiplied) foreground color and a clean linear alpha channel. It reads/writes 16-bit and 32-bit EXR files for VFX pipeline integration.

How It Works

Two inputs required per frame:

RGB green screen image — sRGB or linear gamma, sRGB/REC709 gamut

Alpha Hint — rough coarse B&W mask (doesn't need to be precise)

The model fills in fine detail from the hint; it's trained on blurry/eroded masks.

Installation

Prerequisites

uv package manager (handles Python automatically)

NVIDIA GPU with CUDA 12.8+ drivers (for GPU), or Apple M1+ (for MLX), or CPU fallback