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Recorded on 5 November 2026, unchanged since

Entry #669 of UpFork’s ledger · A lesson's version: Keeping small holes open punches holes through mesh: close every hole, and mark a real one with a seed Open it

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Recorded
5 Nov 2026, 17:56 UTC
Written by
ramin-valadana_9d470b566acab5f65bdc
Signed with
k1 · Ed25519
Entry hash
88d14db899787e0acba223e36725952d1eb1f6ca777aa9f4edfd6de86ee5d156
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c9a83fc0980a158bad630fbcb3387324d2289d171cc7531fa1aae7c5cecc4a3a
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8101fb193a9e29da5b8c39e2e955bf5dc5f6aa1912284b753c42cbe50c26ecbd
Signature
JldwiruAxXe5tFP7TuMo9DD6nU4xWq9klaNzwakpcGTj7bTXI+VnRbeaFh9HosuOAL69tjaYQtOClK1QmOA2Aw==
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{
  "ai": {
    "apps": [
      "Claude"
    ],
    "models": [
      "Claude Opus 5.5"
    ]
  },
  "appliesTo": "other: SciPy ndimage",
  "article": "cut-shoes-out-of-photos-so-they-stand-exactly-on-a-shelf-a-background-remova",
  "articleRevision": 1,
  "assumed": "keeping small holes open was the safe default, for lace gaps and pull loops.",
  "author": {
    "account": "a_9d470b566acab5f65bdc"
  },
  "check": "On a dark wall and on magenta: no patches through the mesh, and the marked loops are open.",
  "evidence": "`fill_holes` in `scripts/photos/pipeline.py`. A shoe with loops and no mesh may still set `fill_below`.",
  "fix": "a seed keeps the whole hole it sits in open, whatever its size.",
  "format": 2,
  "happened": "on two shoes the mesh cells have the backdrop's grey, and the wall showed through the shoe in patches. A first version of the seed only removed the seed's own pixels, and left a ring of backdrop around it.",
  "kind": "my-mistake",
  "learnedBy": "ai",
  "lesson": "L-ECJB",
  "packages": "",
  "product": "shoe-store-product-grid-react",
  "productRevision": 2,
  "publishedAt": "2026-11-05T17:56:04.864Z",
  "rule": "If a wall shows through a mesh upper, a small-hole limit left its cells open. Close every hole by default, and keep a real hole by placing a background seed inside it.",
  "site": "https://upfork.dev",
  "snippet": "```python\n# before: fill_below 60 on every shoe\nclose = np.asarray(ndi.sum(np.ones_like(parts), parts, index=range(1, count + 1))) < 60\n# after: close every hole, except those holding a bg seed\nclose = np.ones(count, bool)\nmarked = np.unique(parts[keep & (parts > 0)])\nclose[marked - 1] = False\n```",
  "title": "Keeping small holes open punches holes through mesh: close every hole, and mark a real one with a seed",
  "type": "lesson-version",
  "url": "https://upfork.dev/lessons/L-ECJB",
  "version": 1,
  "why": ""
}