lhk229 7555321cfc Simplify to single-segmenter pipelines; add screen_color prior; drop rescue + recolor
Strategic pivot: the dropout-fill rescue, the anime-seg fill backend, the
BiRefNet+anime-seg intersection, and the recolor pass all existed to repair
source images whose hair was already green-contaminated or broken at generation
time. Fixing the source instead (clean pastel-background generation) makes the
matte high-contrast, so that whole compensation layer is unnecessary. Remove it.

- Two pipelines via segmentation.enabled:
    false -> chroma-only (Chroma + ViTMatte)
    true  -> single segmenter (default anime-seg, switchable birefnet) -> trimap
  then ViTMatte refines, pymatting estimates foreground, despill cleans spill.

- Generalise the green-hardcoded colour logic to a screen_color prior (hex, e.g.
  "#CFEFFF"; default null = green auto-detect, byte-identical). chroma keys off
  Lab/RGB distance to the colour; despill removes chroma along its Lab direction.
  Added --screen-color CLI flag.

- Removed dead code: fill_seg_dropouts + seg_fill*/intersection params,
  SegmentationSettings.fill_backend/fill_model_name/sharpen, unsharp_mask,
  recolor.py + RecolorSettings.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-01 15:33:58 +08:00

BgFilter

Offline green screen character matting for AI-generated character images.

The first implementation follows the workflow in docs/green_screen_matting_workflow.md:

RGB input -> chroma confidence -> trimap -> ViTMatte -> alpha cleanup -> despill -> RGBA PNG -> QA previews

Environment

Use the conda environment lightML.

conda activate lightML
pip install -r requirements.txt

If the shell is not activated, call the environment Python directly:

D:\MiniConda\envs\lightML\python.exe -m bgfilter.cli --help

Single Image

D:\MiniConda\envs\lightML\python.exe -m bgfilter.cli `
  --input Samples\TestImage.png `
  --output Outputs\TestImage_rgba.png `
  --debug-dir Outputs\TestImage_debug `
  --config configs\default.yaml `
  --device cuda

The CLI reads configs/default.yaml when --config is provided. Command-line options override config values, so tuning can usually happen in YAML while runtime choices such as --device cpu stay on the command line.

Use CPU for validation when CUDA is unavailable:

D:\MiniConda\envs\lightML\python.exe -m bgfilter.cli `
  --input Samples\TestImage.png `
  --output Outputs\TestImage_rgba.png `
  --debug-dir Outputs\TestImage_debug `
  --config configs\default.yaml `
  --device cpu

Batch

D:\MiniConda\envs\lightML\python.exe -m bgfilter.cli `
  --input-dir Samples `
  --output-dir Outputs `
  --debug-dir Outputs\debug `
  --config configs\default.yaml `
  --device cuda

Chroma-Only Debug Mode

This mode skips ViTMatte and uses chroma confidence as an alpha seed. It is useful for fast debugging of chroma confidence, trimap, despill, and QA outputs.

D:\MiniConda\envs\lightML\python.exe -m bgfilter.cli `
  --input-dir Samples `
  --output-dir Outputs\chroma `
  --debug-dir Outputs\chroma_debug `
  --config configs\default.yaml `
  --matting-method chroma `
  --device cpu

Outputs

For each processed image, the CLI writes an RGBA PNG and optional debug files:

bg_confidence.png
trimap.png
alpha.png
foreground_rgb.png
foreground_background.png
foreground_correction.png
despill_mask.png
preview_black.png
preview_white.png
preview_gray.png
preview_red.png
preview_blue.png
qa_grid.png
metadata.json

Quality Check

The quality checker measures alpha validity and green spill on semi-transparent edge pixels.

D:\MiniConda\envs\lightML\python.exe -m bgfilter.quality_cli `
  Outputs\TestImage_rgba.png `
  --max-edge-green-excess-p95 0.30

Run the bundled sample smoke check:

D:\MiniConda\envs\lightML\python.exe scripts\smoke_samples.py `
  --samples-dir Samples `
  --output-dir Outputs\smoke_samples `
  --config configs\default.yaml `
  --device cpu `
  --fallback-to-chroma-alpha `
  --max-edge-green-excess-p95 0.30

Current Notes

  • Samples/ and Outputs/ are ignored by Git.
  • ViTMatte model weights are loaded from Hugging Face on first use.
  • Foreground color estimation uses pymatting's estimate_foreground_ml to propagate clean foreground colour into semi-transparent edges before final de-spill, writing the estimated foreground, background, and a correction map. Set foreground.method: unmix to fall back to the legacy heuristic.
S
Description
No description provided
Readme 1 MiB
Languages
Python 100%