Initial Dansori EQ workspace

tools/clean_character_alpha.py

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+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+
+from PIL import Image, ImageFilter
+
+
+def clean_alpha(src: Path, dst: Path) -> tuple[int, int]:
+    img = Image.open(src).convert("RGBA")
+    w, h = img.size
+    px = img.load()
+
+    alpha = img.getchannel("A")
+    solid = alpha.point(lambda a: 255 if a > 8 else 0)
+    inner = solid.filter(ImageFilter.MinFilter(21))
+    edge = Image.new("L", img.size, 0)
+    edge.paste(solid)
+    edge_px = edge.load()
+    inner_px = inner.load()
+
+    removed = 0
+    softened = 0
+    for y in range(h):
+        upper_zone = y < int(h * 0.55)
+        for x in range(w):
+            r, g, b, a = px[x, y]
+            if a == 0:
+                continue
+
+            near_edge = edge_px[x, y] and not inner_px[x, y]
+            if not near_edge and a > 225:
+                continue
+
+            bright = (r + g + b) / 3
+            chroma = max(r, g, b) - min(r, g, b)
+            semi = a < 245
+
+            neutral_matte = semi and bright > 118 and chroma < 82
+            pink_or_cyan_matte = (
+                semi
+                and upper_zone
+                and bright > 130
+                and (
+                    (r > 135 and b > 130 and g > 80)
+                    or (g > 135 and b > 130 and r < 175)
+                )
+                and chroma < 135
+            )
+
+            if near_edge and (neutral_matte or pink_or_cyan_matte):
+                px[x, y] = (r, g, b, 0)
+                removed += 1
+            elif semi and neutral_matte:
+                px[x, y] = (r, g, b, int(a * 0.2))
+                softened += 1
+
+    dst.parent.mkdir(parents=True, exist_ok=True)
+    img.save(dst)
+    return removed, softened
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("paths", nargs="+", type=Path)
+    parser.add_argument("--in-place", action="store_true")
+    args = parser.parse_args()
+
+    for path in args.paths:
+        dst = path if args.in_place else path.with_name(path.stem + "_clean.png")
+        removed, softened = clean_alpha(path, dst)
+        print(f"{path} -> {dst} removed={removed} softened={softened}")
+
+
+if __name__ == "__main__":
+    main()