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name: inference-and-demo description: "Routes BackgroundMattingV2 image, video, webcam, and throughput demo workflows." disable-model-invocation: true metadata: disco-role: operating license: MIT

inference-and-demo

Use this sub-skill when the task is about running BackgroundMattingV2 demos or understanding the inference-time model path.

Typical triggers

• image matting on a directory of source/background images
• video matting on a source video and a background image or video
• webcam matting, background capture, or GUI interaction
• throughput or speed testing on PyTorch or TorchScript
• choosing mattingbase vs mattingrefine
• choosing resnet101, resnet50, or mobilenetv2
• using cpu vs cuda
• deciding when preprocess-alignment is helpful

Read first

• references/workflows.md for concrete demo recipes and option meaning.
• references/troubleshooting.md for missing checkpoints, shape mismatch, alignment, webcam, and output-overwrite issues.
• scripts/smoke_forward.py for the safe tiny forward smoke.
• scripts/run_inference_images.py and scripts/run_inference_video.py for dry-run or execute wrappers around the checkout's demo CLIs.

What this sub-skill owns

• model selection and inference-time configuration
• input pairing and alignment behavior
• output types com, pha, fgr, err, and ref
• small smoke tests that prove the model path works without checkpoints
• guidance for the webcam demo, while acknowledging its hardware and GUI needs

What it does not own

• TorchScript or ONNX conversion details; use export-and-backends.
• Dataset layout and training setup; use training.
• Octave/MATLAB benchmark notes; those stay with training references.

Recommended first checks

1. Run scripts/smoke_forward.py with a tiny resolution on CPU or CUDA.
2. If you only want to inspect the exact source CLI, use the dry-run wrappers.
3. Move to the native CLI only when you have a real checkpoint and matching source/background inputs.

Cross-links

• ../export-and-backends/SKILL.md
• ../training/SKILL.md
• ../../references/backend-compatibility.md