Files
BGfilter/bgfilter/pipeline.py
T
lhk229 72655dea91 Gate seg-reuse to the birefnet backend
reuse_as_seg swaps one BiRefNet-family model for another (the validated
equivalence); it must not silently override an explicitly chosen anime-seg
backend. With --seg-backend anime-seg the segmenter now keeps its own
forward and the cross-check veto runs independently on top -- both
combinable, no flag juggling. Default birefnet path is untouched
(verified byte-identical); anime-seg + cross-check verified to run both
models.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-06 15:52:21 +08:00

210 lines
7.6 KiB
Python

from __future__ import annotations
import json
from dataclasses import asdict
from pathlib import Path
import numpy as np
from .alpha_post import (
clean_alpha,
cross_check_alpha,
enforce_trimap,
suppress_alpha_by_chroma,
)
from .chroma import (
bg_hue_projection,
compute_bg_confidence,
convert_color_spaces,
parse_hex_color,
)
from .despill import despill
from .foreground import estimate_foreground_rgb
from .io import load_rgb, save_gray, save_rgb, save_rgba, write_text
from .qa import BACKGROUND_COLORS, composite, make_qa_grid, save_previews
from .settings import PipelineSettings, SegmentationSettings
from .trimap import (
fuse_trimap,
fuse_trimap_directional,
generate_trimap,
trimap_to_alpha_seed,
)
from .vitmatte_infer import ViTMatteRunner
class MattingPipeline:
def __init__(self, settings: PipelineSettings):
self.settings = settings
self._runner: ViTMatteRunner | None = None
self._segmenter = None
self._cross_checker = None
def _segment(self, rgb: np.ndarray) -> np.ndarray:
if self._segmenter is None:
from .segmentation import make_segmenter
self._segmenter = make_segmenter(self.settings.segmentation)
return self._segmenter.mask(rgb)
def _second_opinion(self, rgb: np.ndarray) -> np.ndarray:
if self._cross_checker is None:
from .segmentation import BiRefNetSegmenter
check = self.settings.cross_check
self._cross_checker = BiRefNetSegmenter(
SegmentationSettings(
model_name=check.model_name,
device=self.settings.segmentation.device,
input_size=check.input_size,
precision=check.precision,
)
)
return self._cross_checker.mask(rgb)
def _predict_alpha(self, rgb: np.ndarray, trimap: np.ndarray, bg_confidence: np.ndarray) -> tuple[np.ndarray, str]:
if self.settings.model.matting_method == "chroma":
return trimap_to_alpha_seed(trimap, bg_confidence), "chroma"
if self.settings.model.matting_method != "vitmatte":
raise RuntimeError(
f"Unsupported matting method '{self.settings.model.matting_method}'. "
"Use 'vitmatte' or 'chroma'."
)
try:
if self._runner is None:
self._runner = ViTMatteRunner(self.settings.model)
return self._runner.predict(rgb, trimap), "vitmatte"
except RuntimeError:
if not self.settings.model.fallback_to_chroma_alpha:
raise
return trimap_to_alpha_seed(trimap, bg_confidence), "chroma_fallback"
def run_image(
self,
input_path: str | Path,
output_path: str | Path,
debug_dir: str | Path | None,
) -> dict:
return _run_image(input_path, output_path, debug_dir, self)
def run_image(
input_path: str | Path,
output_path: str | Path,
debug_dir: str | Path | None,
settings: PipelineSettings,
) -> dict:
return MattingPipeline(settings).run_image(input_path, output_path, debug_dir)
def _run_image(
input_path: str | Path,
output_path: str | Path,
debug_dir: str | Path | None,
pipeline: MattingPipeline,
) -> dict:
settings = pipeline.settings
rgb = load_rgb(input_path)
screen_color = parse_hex_color(settings.screen_color) if settings.screen_color else None
bg_confidence, model = compute_bg_confidence(
rgb, settings=settings.chroma, screen_color=screen_color
)
second_alpha = None
if settings.segmentation.enabled:
reuse = (
settings.cross_check.enabled
and settings.cross_check.reuse_as_seg
# Reuse swaps one BiRefNet-family model for another (validated
# equivalent topology). A different backend chosen explicitly
# (anime-seg) keeps its own forward; cross-check still runs
# independently on top of it.
and settings.segmentation.backend == "birefnet"
)
if reuse:
# One HR-matting forward serves both the trimap topology and the
# cross-check second opinion; the primary seg model is never loaded.
second_alpha = pipeline._second_opinion(rgb)
seg_mask = second_alpha
else:
seg_mask = pipeline._segment(rgb)
mode = settings.trimap.mode
if mode == "seg":
trimap, trimap_stats = fuse_trimap(seg_mask, bg_confidence, settings.trimap)
elif mode in ("directional", "directional-hard-bg"):
lab = convert_color_spaces(rgb)[1]
trimap, trimap_stats = fuse_trimap_directional(
seg_mask, bg_confidence, lab, model.lab_center, settings.trimap
)
else:
raise RuntimeError(
f"Unknown trimap.mode '{mode}'. "
"Use 'directional', 'seg', or 'directional-hard-bg'."
)
else:
seg_mask = None
trimap, trimap_stats = generate_trimap(bg_confidence, settings.trimap)
raw_alpha, alpha_source = pipeline._predict_alpha(rgb, trimap, bg_confidence)
alpha = enforce_trimap(raw_alpha, trimap)
alpha = suppress_alpha_by_chroma(
alpha, bg_confidence, trimap, settings.alpha_post,
# The matte-confidence gate only makes sense for a real matting prediction;
# a chroma-seeded alpha is itself colour evidence, so no gate there.
raw_alpha=raw_alpha if alpha_source == "vitmatte" else None,
)
alpha = clean_alpha(alpha, trimap, settings.alpha_post)
if settings.cross_check.enabled:
lab = convert_color_spaces(rgb)[1]
if second_alpha is None:
second_alpha = pipeline._second_opinion(rgb)
alpha = cross_check_alpha(
alpha,
second_alpha,
bg_hue_projection(lab, model.lab_center),
lab[..., 0],
trimap,
settings.cross_check,
)
foreground = estimate_foreground_rgb(
rgb, alpha, bg_confidence, model, settings.foreground
)
corrected_rgb, color_mask = despill(
foreground.rgb, alpha, model, settings.despill
)
save_rgba(output_path, corrected_rgb, alpha)
result = {
"input": str(input_path),
"output": str(output_path),
"alpha_source": alpha_source,
"background_model": model.to_dict(),
"trimap": trimap_stats,
"settings": asdict(settings),
}
if debug_dir is not None:
debug = Path(debug_dir)
debug.mkdir(parents=True, exist_ok=True)
save_gray(debug / "bg_confidence.png", bg_confidence)
save_gray(debug / "trimap.png", trimap)
if seg_mask is not None:
save_gray(debug / "seg_mask.png", seg_mask)
if second_alpha is not None:
save_gray(debug / "cross_check_alpha.png", second_alpha)
save_gray(debug / "alpha.png", alpha)
save_rgb(debug / "foreground_rgb.png", corrected_rgb)
save_gray(debug / "color_mask.png", color_mask)
save_previews(debug, corrected_rgb, alpha)
tiles = {
"input": rgb,
"bg confidence": np.repeat((bg_confidence[..., None] * 255).astype(np.uint8), 3, axis=2),
"trimap": np.repeat(trimap[..., None], 3, axis=2),
"alpha": np.repeat((alpha[..., None] * 255).astype(np.uint8), 3, axis=2),
}
for name, color in BACKGROUND_COLORS.items():
tiles[f"preview {name}"] = composite(corrected_rgb, alpha, color)
make_qa_grid(debug, tiles)
write_text(debug / "metadata.json", json.dumps(result, indent=2, ensure_ascii=False))
return result