Film Grain is a Rust renderer for physically based film grain built on Monte Carlo-filtered Boolean models. It implements both the pixel-wise and grain-wise algorithms from Newson et al. (2017). The core library powers a command-line tool (film_grain) for batch work and an egui/wgpu viewer (viewer) for interactive tweaking.

• Pixel-wise and grain-wise Monte Carlo integrators with automatic selection and both CPU/GPU backends.
• Comprehensive parameterization: luma/RGB modes, ROI cropping, zoom or explicit sizing, deterministic seeding, dry-run/explain flags, and flexible output formats.
• CPU/GPU execution with deterministic seeding, ROI cropping, zoom or fixed sizing, RGB/luma modes, and dry-run/explain flags for inspection.
• tools/film_grain_bench.py sweeps parameter grids to benchmark pixel vs. grain renderers across CPU/GPU variants.

• CLI: cargo run --release -- <input.png> --output out.png --radius 0.12 --iters 64 --device gpu --color-mode luma --explain
• Viewer: cargo run --release --bin viewer.

• cargo test to validate the workspace.
• tools/film_grain_bench.py builds release binaries and sweeps parameter grids when you need performance data.