- Implement film grain effect with customizable parameters (scale, strength, saturation, toe, seed)
- Use pure PyTorch operations for better GPU utilization (no OpenCV dependencies)
- Apply ITU-R BT.709 color space conversion for accurate grain distribution
- Implement screen blend mode for better highlight preservation
- Add channel-specific weighting matching real film characteristics (3x blue, 2x red)
- Preserve alpha channel when present
- Add comprehensive test suite (20 tests covering all functionality)
- Include documentation and example workflow
- Register node under ComfyAssets/image category
Improvements over reference implementation:
- More efficient memory management avoiding numpy/OpenCV conversions
- Better grain mixing algorithm with proper color science
- Improved performance through PyTorch-native operations