add benchmark script

scripts/bench_pipeline.py

@@ -0,0 +1,68 @@
+"""Benchmark the default matting pipeline (excludes model-load time).
+
+Runs the default config (base ViTMatte + BiRefNet + directional trimap) with a
+fixed screen_color over TestImage3/4, timing 10 in-memory runs after a warmup
+that loads the models. Saves only the last output to Outputs/.
+
+    python scripts/bench_pipeline.py
+"""
+
+from __future__ import annotations
+
+import sys
+import time
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO))
+
+from bgfilter.config import load_settings, override_settings
+from bgfilter.io import load_rgb, save_rgba
+from bgfilter.pipeline import MattingPipeline
+
+SCREEN_COLOR = "#CFEFFF"
+IMAGES = ["TestImage3.png", "TestImage4.png"]
+N = 10
+
+
+def main() -> None:
+    settings = override_settings(
+        load_settings(str(REPO / "configs" / "default.yaml")),
+        screen_color=SCREEN_COLOR,
+    )
+    pipe = MattingPipeline(settings)
+    imgs = {name: load_rgb(REPO / "samples" / name) for name in IMAGES}
+
+    # Warmup: loads ViTMatte + BiRefNet and triggers one-time JIT. NOT timed.
+    t0 = time.perf_counter()
+    pipe.run_rgb(imgs[IMAGES[0]])
+    print(f"warmup (model load + first run): {time.perf_counter() - t0:.1f}s", flush=True)
+
+    runs: list[tuple[str, float]] = []
+    last = None
+    for i in range(N):
+        name = IMAGES[i % len(IMAGES)]
+        t0 = time.perf_counter()
+        res = pipe.run_rgb(imgs[name])
+        dt = time.perf_counter() - t0
+        runs.append((name, dt))
+        last = (name, res)
+        print(f"  run {i + 1:2d}  {name:16s} {dt:6.2f}s", flush=True)
+
+    ts = [d for _, d in runs]
+    total = sum(ts)
+    print(f"\n{N} runs: total {total:.2f}s  avg {total / N:.2f}s  "
+          f"min {min(ts):.2f}s  max {max(ts):.2f}s")
+    for name in IMAGES:
+        d = [x for nm, x in runs if nm == name]
+        if d:
+            print(f"  {name}: avg {sum(d) / len(d):.2f}s over {len(d)} runs")
+
+    name, res = last
+    out = REPO / "Outputs" / (Path(name).stem + "_rgba.png")
+    save_rgba(out, res.rgb, res.alpha)
+    print(f"saved last output -> {out}", flush=True)
+
+
+if __name__ == "__main__":
+    main()