merge: 像素化 v5 批落籍——白边/噪点三连防线(α腐蚀1环+despeckle+边缘色内插),深底测试条八只全过;PNG透明通道答疑=对话式生图输出压平RGB无解,继续算法路线

tools/pixelize_candidates.py

@@ -13,7 +13,7 @@ v3 演进(2026-09-27 用户四问题:脏点/模糊/信息丢失/白边):
 """
 import sys, os
 from collections import deque, Counter
-from PIL import Image
+from PIL import Image, ImageFilter
 
 SIZES = {"goblin": 96, "giant_spider": 96, "hook_horror": 96,
          "bugbear": 128, "duergar": 128,
@@ -237,16 +237,74 @@ def crop_content(im, pad=2):
     r, b = min(im.width, r + pad), min(im.height, b + pad)
     return im.crop((l, t, r, b))
 
+def despeckle(spr, min_px=10):
+    """删小于 min_px 的不透明孤立连通域(噪点)。"""
+    w, hgt = spr.size
+    pa = spr.load()
+    seen = [[False] * w for _ in range(hgt)]
+    for y0 in range(hgt):
+        for x0 in range(w):
+            if seen[y0][x0] or pa[x0, y0][3] == 0:
+                continue
+            comp = []
+            q = deque([(x0, y0)])
+            seen[y0][x0] = True
+            while q:
+                x, y = q.popleft()
+                comp.append((x, y))
+                for dx, dy in ((1, 0), (-1, 0), (0, 1), (0, -1)):
+                    nx, ny = x + dx, y + dy
+                    if 0 <= nx < w and 0 <= ny < hgt and not seen[ny][nx] and pa[nx, ny][3] != 0:
+                        seen[ny][nx] = True
+                        q.append((nx, ny))
+            if len(comp) < min_px:
+                for x, y in comp:
+                    pa[x, y] = (0, 0, 0, 0)
+    return spr
+
+def edge_inpaint(spr, passes=2):
+    """边缘色内插:与透明相邻的不透明像素改色为其内部邻居均值(灭白边,不削轮廓)。"""
+    w, hgt = spr.size
+    for _ in range(passes):
+        pa = spr.load()
+        fixes = []
+        for y in range(hgt):
+            for x in range(w):
+                c = pa[x, y]
+                if c[3] == 0:
+                    continue
+                inner, boundary = [], False
+                for dx, dy in ((1, 0), (-1, 0), (0, 1), (0, -1), (1, 1), (1, -1), (-1, 1), (-1, -1)):
+                    nx, ny = x + dx, y + dy
+                    if not (0 <= nx < w and 0 <= ny < hgt):
+                        boundary = True
+                        continue
+                    nc = pa[nx, ny]
+                    if nc[3] == 0:
+                        boundary = True
+                    elif all(pa[nx + ddx, ny + ddy][3] != 0
+                             for ddx, ddy in ((1, 0), (-1, 0), (0, 1), (0, -1))
+                             if 0 <= nx + ddx < w and 0 <= ny + ddy < hgt):
+                        inner.append(nc)
+                if boundary and inner:
+                    fixes.append((x, y, tuple(sum(ch[i] for ch in inner) // len(inner) for i in range(3))))
+        for x, y, c in fixes:
+            r, g, b, a = pa[x, y]
+            pa[x, y] = (c[0], c[1], c[2], a)
+    return spr
+
 def pixelize(im, target):
-    """BOX 预滤到 4x → 量化 → NEAREST 到 1x(最长边=档位值)。"""
+    """BOX 预滤到 4x(α腐蚀2px灭混合带) → 量化 → NEAREST → 降噪点 → 边缘内插。"""
     src = crop_content(im)
     scale = target * 4 / max(src.size)
     pre = src.resize((max(1, round(src.width * scale)), max(1, round(src.height * scale))), Image.BOX)
     rgb = pre.convert("RGB")
     flat = rgb.quantize(QUANT_COLORS, method=Image.MEDIANCUT).convert("RGB")
     out = flat.resize((max(1, round(pre.width / 4)), max(1, round(pre.height / 4))), Image.NEAREST)
-    a = pre.getchannel("A").resize(out.size, Image.NEAREST).point(lambda v: 255 if v > 128 else 0)
+    a = pre.getchannel("A").filter(ImageFilter.MinFilter(3)).resize(out.size, Image.NEAREST).point(lambda v: 255 if v > 128 else 0)
     out.putalpha(a)
+    despeckle(out)
+    edge_inpaint(out)
     return out
 
 def strip(spr, path):