FAILURE MAP
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FA-50901 / Raster clipping / Open access

Clip mask morphology: closing order · case 01

Closing performs opening and deletes narrow coverage instead of closing holes.

Verified by executionVariant 1 · 12 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Closing performs opening and deletes narrow coverage instead of closing holes.

THE FAILURE

Closing performs opening and deletes narrow coverage instead of closing holes.

Unsuccessful approach: Keeping only dilation fills holes but also expands the outer coverage boundary.

Case contract

A binary sample mask supports dilation/erosion by an explicit signed structuring element. Out-of-target samples are uncovered; empty structuring elements yield empty output. Open erodes then dilates; close dilates then erodes. Gradient is dilated minus eroded; boundary is original minus eroded; exterior boundary is dilated minus original. Iterations use complete prior masks.

Why this case matters

Raster clip state can leak coverage across draws even when every individual region is valid.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(commands, size):
    full=set(range(size))
    out=[]
    for cmd in commands:
        source,kernel,mode,iterations=cmd
        source=set(source)&full
        kernel=set(kernel)
        def dilate(s): return {x for x in full if any(x-k in s for k in kernel)}
        def erode(s): return {x for x in full if kernel and all(x+k in s for k in kernel)}
        result=set(source)
        for _ in range(max(0,iterations)):
            prior=set(result)
            if mode=='dilate': result=dilate(prior)
            elif mode=='erode': result=erode(prior)
            elif mode=='open': result=dilate(erode(prior))
            elif mode=='close': result=dilate(erode(prior))
            elif mode=='gradient': result=dilate(prior)-erode(prior)
            elif mode=='inner': result=prior-erode(prior)
            else: result=dilate(prior)-prior
        out.append(sorted(result))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 4), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 4), [[1, 2]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 4), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 4), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 4), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 4), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 4), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 4), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 4), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 4), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 4), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 4), [[0, 1, 2]])
if N == 2:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 5), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 5), [[1, 2, 3]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 5), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 5), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 5), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 5), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 5), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 5), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 5), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 5), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 5), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 5), [[0, 1, 2]])
if N == 3:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 6), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 6), [[1, 2, 3, 4]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 6), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 6), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 6), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 6), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 6), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 6), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 6), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 6), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 6), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 6), [[0, 1, 2]])
if N == 4:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 7), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 7), [[1, 2, 3, 4, 5]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 7), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 7), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 7), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 7), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 7), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 7), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 7), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 7), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 7), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 7), [[0, 1, 2]])
if N == 5:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 8), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 8), [[1, 2, 3, 4, 5, 6]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 8), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 8), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 8), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 8), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 8), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 8), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 8), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 8), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 8), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 8), [[0, 1, 2]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
explicit sequence 0[[1, 2]][[1, 2]]Passed
explicit sequence 1[[1, 2]][[1, 2]]Passed
explicit sequence 2[[]][[]]Passed
explicit sequence 3[[]][[]]Passed
explicit sequence 4[[]][[0, 1, 2]]Failed
explicit sequence 5[[2, 3]][[2, 3]]Passed
explicit sequence 6[[2]][[2]]Passed
explicit sequence 7[[2]][[2]]Passed
explicit sequence 8[[0, 1, 2]][[0, 1, 2]]Passed
explicit sequence 9[[1]][[1]]Passed
explicit sequence 10[[1, 2]][[1, 2]]Passed
explicit sequence 11[[0, 1, 2]][[0, 1, 2]]Passed

SHA-256 / 4ba2d9aba317d0ec19f1a963b36669b5e705ae52a1e247e12d05a338889378a0

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(commands, size):
    full=set(range(size))
    out=[]
    for cmd in commands:
        source,kernel,mode,iterations=cmd
        source=set(source)&full
        kernel=set(kernel)
        def dilate(s): return {x for x in full if any(x-k in s for k in kernel)}
        def erode(s): return {x for x in full if kernel and all(x+k in s for k in kernel)}
        result=set(source)
        for _ in range(max(0,iterations)):
            prior=set(result)
            if mode=='dilate': result=dilate(prior)
            elif mode=='erode': result=erode(prior)
            elif mode=='open': result=dilate(erode(prior))
            elif mode=='close': result=dilate(prior)
            elif mode=='gradient': result=dilate(prior)-erode(prior)
            elif mode=='inner': result=prior-erode(prior)
            else: result=dilate(prior)-prior
        out.append(sorted(result))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 4), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 4), [[1, 2]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 4), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 4), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 4), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 4), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 4), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 4), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 4), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 4), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 4), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 4), [[0, 1, 2]])
if N == 2:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 5), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 5), [[1, 2, 3]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 5), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 5), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 5), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 5), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 5), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 5), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 5), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 5), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 5), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 5), [[0, 1, 2]])
if N == 3:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 6), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 6), [[1, 2, 3, 4]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 6), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 6), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 6), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 6), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 6), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 6), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 6), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 6), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 6), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 6), [[0, 1, 2]])
if N == 4:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 7), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 7), [[1, 2, 3, 4, 5]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 7), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 7), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 7), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 7), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 7), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 7), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 7), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 7), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 7), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 7), [[0, 1, 2]])
if N == 5:
    check('explicit sequence 0', solve([[[1], [0, 1], 'dilate', 1]], 8), [[1, 2]])
    check('explicit sequence 1', solve([[[0, 1, 2, 3, 4, 5, 6, 7], [-1, 0, 1], 'erode', 1]], 8), [[1, 2, 3, 4, 5, 6]])
    check('explicit sequence 2', solve([[[1], [], 'erode', 1]], 8), [[]])
    check('explicit sequence 3', solve([[[1], [0, 1], 'open', 1]], 8), [[]])
    check('explicit sequence 4', solve([[[0, 2], [0, 1], 'close', 1]], 8), [[0, 1, 2]])
    check('explicit sequence 5', solve([[[0, 1, 2], [0, 1], 'gradient', 1]], 8), [[2, 3]])
    check('explicit sequence 6', solve([[[0, 1, 2], [0, 1], 'inner', 1]], 8), [[2]])
    check('explicit sequence 7', solve([[[1], [0, 1], 'outer', 1]], 8), [[2]])
    check('explicit sequence 8', solve([[[0], [0, 1], 'dilate', 2]], 8), [[0, 1, 2]])
    check('explicit sequence 9', solve([[[1], [0, 1], 'dilate', 0]], 8), [[1]])
    check('explicit sequence 10', solve([[[2], [-1, 0], 'dilate', 1]], 8), [[1, 2]])
    check('explicit sequence 11', solve([[[0, 1, 2], [0, 1], 'open', 1]], 8), [[0, 1, 2]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
explicit sequence 0[[1, 2]][[1, 2]]Passed
explicit sequence 1[[1, 2]][[1, 2]]Passed
explicit sequence 2[[]][[]]Passed
explicit sequence 3[[]][[]]Passed
explicit sequence 4[[0, 1, 2, 3]][[0, 1, 2]]Failed
explicit sequence 5[[2, 3]][[2, 3]]Passed
explicit sequence 6[[2]][[2]]Passed
explicit sequence 7[[2]][[2]]Passed
explicit sequence 8[[0, 1, 2]][[0, 1, 2]]Passed
explicit sequence 9[[1]][[1]]Passed
explicit sequence 10[[1, 2]][[1, 2]]Passed
explicit sequence 11[[0, 1, 2]][[0, 1, 2]]Passed

SHA-256 / 78d4b125fa9689130997677298e949aaef5fbca39b94e9f36fd041a0f2c3e43b

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 12 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

Finite one-dimensional integer sample sets model coverage state only; no geometric intersection, memory layout, GPU or graphics-standard conformance is claimed. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:45:13.848419+00:00.

Case digest / 5e8e8b7db39d6ebf0b42f437a08773b2a5a943825eb0744073a0e11fd8a6b5ae