FAILURE MAP
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FA-79176 / Image orientation metadata / Open access

Canvas rotation for tag 8 shifts by the height · case 01

Counter-clockwise photos are cut off at the bottom of the canvas.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

y' = w - x needs a translation of w, but h is used.

THE FAILURE

y' = w - x needs a translation of w, but h is used.

Unsuccessful approach: Flipping both rotation signs turns the matrix into a clockwise turn shifted the wrong way.

Case contract

Input [w, h, tag]. Produce the canvas size and the 2D affine [a, b, c, d, e, f] (x' = a*x + c*y + e, y' = b*x + d*y + f, continuous coordinates, so mirroring an extent e maps x to e - x) that draws the stored image upright. Tags 5..8 use a [h, w] canvas; invalid tags are treated as 1.

Why this case matters

Camera, phone and scanner images carry an orientation hint separately from the stored pixels; galleries, thumbnailers, editors and upload pipelines must interpret it consistently or photos appear sideways, mirrored or doubly rotated.

1 / The failure

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

N = 1
observations = []
def solve(x):
    w, h, tag = x
    if tag not in (1, 2, 3, 4, 5, 6, 7, 8):
        tag = 1
    if tag == 1:
        mat = [1, 0, 0, 1, 0, 0]
    elif tag == 2:
        mat = [-1, 0, 0, 1, w, 0]
    elif tag == 3:
        mat = [-1, 0, 0, -1, w, h]
    elif tag == 4:
        mat = [1, 0, 0, -1, 0, h]
    elif tag == 5:
        mat = [0, 1, 1, 0, 0, 0]
    elif tag == 6:
        mat = [0, 1, -1, 0, h, 0]
    elif tag == 7:
        mat = [0, -1, -1, 0, h, w]
    else:
        mat = [0, -1, 1, 0, 0, h]
    canvas = [h, w] if tag >= 5 else [w, h]
    return {'canvas': canvas, 'matrix': mat}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[[[1435, 891, 8], {'canvas': [891, 1435], 'matrix': [0, -1, 1, 0, 0, 1435]}], [[2552, 2696, 8], {'canvas': [2696, 2552], 'matrix': [0, -1, 1, 0, 0, 2552]}], [[3307, 2787, 3], {'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}], [[2954, 1709, 1], {'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}], [[58, 1879, 3], {'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}], [[2834, 740, 9], {'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1990, 1071, 4], {'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}], [[1404, 2174, 8], {'canvas': [2174, 1404], 'matrix': [0, -1, 1, 0, 0, 1404]}]], [[[573, 2362, 8], {'canvas': [2362, 573], 'matrix': [0, -1, 1, 0, 0, 573]}], [[3240, 3198, 8], {'canvas': [3198, 3240], 'matrix': [0, -1, 1, 0, 0, 3240]}], [[2349, 3183, 4], {'canvas': [2349, 3183], 'matrix': [1, 0, 0, -1, 0, 3183]}], [[3672, 2107, 7], {'canvas': [2107, 3672], 'matrix': [0, -1, -1, 0, 2107, 3672]}], [[497, 2889, 6], {'canvas': [2889, 497], 'matrix': [0, 1, -1, 0, 2889, 0]}], [[1679, 3857, 0], {'canvas': [1679, 3857], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1194, 3699, 6], {'canvas': [3699, 1194], 'matrix': [0, 1, -1, 0, 3699, 0]}], [[3117, 2247, 8], {'canvas': [2247, 3117], 'matrix': [0, -1, 1, 0, 0, 3117]}]], [[[3582, 1031, 8], {'canvas': [1031, 3582], 'matrix': [0, -1, 1, 0, 0, 3582]}], [[2823, 328, 8], {'canvas': [328, 2823], 'matrix': [0, -1, 1, 0, 0, 2823]}], [[2580, 3384, 7], {'canvas': [3384, 2580], 'matrix': [0, -1, -1, 0, 3384, 2580]}], [[1742, 3974, 6], {'canvas': [3974, 1742], 'matrix': [0, 1, -1, 0, 3974, 0]}], [[2878, 1614, 0], {'canvas': [2878, 1614], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1553, 978, 5], {'canvas': [978, 1553], 'matrix': [0, 1, 1, 0, 0, 0]}], [[2394, 1311, 0], {'canvas': [2394, 1311], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1397, 2252, 8], {'canvas': [2252, 1397], 'matrix': [0, -1, 1, 0, 0, 1397]}]], [[[3353, 3003, 8], {'canvas': [3003, 3353], 'matrix': [0, -1, 1, 0, 0, 3353]}], [[715, 3871, 8], {'canvas': [3871, 715], 'matrix': [0, -1, 1, 0, 0, 715]}], [[1728, 2634, 3], {'canvas': [1728, 2634], 'matrix': [-1, 0, 0, -1, 1728, 2634]}], [[2618, 2128, 9], {'canvas': [2618, 2128], 'matrix': [1, 0, 0, 1, 0, 0]}], [[2422, 1413, 3], {'canvas': [2422, 1413], 'matrix': [-1, 0, 0, -1, 2422, 1413]}], [[3842, 908, 7], {'canvas': [908, 3842], 'matrix': [0, -1, -1, 0, 908, 3842]}], [[1888, 3423, 4], {'canvas': [1888, 3423], 'matrix': [1, 0, 0, -1, 0, 3423]}], [[2003, 798, 8], {'canvas': [798, 2003], 'matrix': [0, -1, 1, 0, 0, 2003]}]], [[[2368, 85, 8], {'canvas': [85, 2368], 'matrix': [0, -1, 1, 0, 0, 2368]}], [[1473, 484, 8], {'canvas': [484, 1473], 'matrix': [0, -1, 1, 0, 0, 1473]}], [[663, 894, 6], {'canvas': [894, 663], 'matrix': [0, 1, -1, 0, 894, 0]}], [[2083, 1309, 2], {'canvas': [2083, 1309], 'matrix': [-1, 0, 0, 1, 2083, 0]}], [[318, 2513, 3], {'canvas': [318, 2513], 'matrix': [-1, 0, 0, -1, 318, 2513]}], [[2840, 2668, 9], {'canvas': [2840, 2668], 'matrix': [1, 0, 0, 1, 0, 0]}], [[3326, 1192, 2], {'canvas': [3326, 1192], 'matrix': [-1, 0, 0, 1, 3326, 0]}], [[1575, 215, 8], {'canvas': [215, 1575], 'matrix': [0, -1, 1, 0, 0, 1575]}]]]
labels = ["regression: tag 8 translation", "repair trap", "combined fault", "control", "control", "boundary", "boundary", "control"]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check("%s %d" % (labels[i % len(labels)], i), solve(args), expected)
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
regression: tag 8 translation 0{'canvas': [891, 1435], 'matrix': [0, -1, 1, 0, 0, 891]}{'canvas': [891, 1435], 'matrix': [0, -1, 1, 0, 0, 1435]}Failed
repair trap 1{'canvas': [2696, 2552], 'matrix': [0, -1, 1, 0, 0, 2696]}{'canvas': [2696, 2552], 'matrix': [0, -1, 1, 0, 0, 2552]}Failed
combined fault 2{'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}{'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}Passed
control 3{'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}{'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}Passed
control 4{'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}{'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}Passed
boundary 5{'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}{'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}Passed
boundary 6{'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}{'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}Passed
control 7{'canvas': [2174, 1404], 'matrix': [0, -1, 1, 0, 0, 2174]}{'canvas': [2174, 1404], 'matrix': [0, -1, 1, 0, 0, 1404]}Failed

SHA-256 / d7e26ac8b848137bc1bb94c2aa958645e50fd98dcb1e40ff2cc219239a494821

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(x):
    w, h, tag = x
    if tag not in (1, 2, 3, 4, 5, 6, 7, 8):
        tag = 1
    if tag == 1:
        mat = [1, 0, 0, 1, 0, 0]
    elif tag == 2:
        mat = [-1, 0, 0, 1, w, 0]
    elif tag == 3:
        mat = [-1, 0, 0, -1, w, h]
    elif tag == 4:
        mat = [1, 0, 0, -1, 0, h]
    elif tag == 5:
        mat = [0, 1, 1, 0, 0, 0]
    elif tag == 6:
        mat = [0, 1, -1, 0, h, 0]
    elif tag == 7:
        mat = [0, -1, -1, 0, h, w]
    else:
        mat = [0, 1, -1, 0, 0, w]
    canvas = [h, w] if tag >= 5 else [w, h]
    return {'canvas': canvas, 'matrix': mat}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[[[1435, 891, 8], {'canvas': [891, 1435], 'matrix': [0, -1, 1, 0, 0, 1435]}], [[2552, 2696, 8], {'canvas': [2696, 2552], 'matrix': [0, -1, 1, 0, 0, 2552]}], [[3307, 2787, 3], {'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}], [[2954, 1709, 1], {'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}], [[58, 1879, 3], {'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}], [[2834, 740, 9], {'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1990, 1071, 4], {'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}], [[1404, 2174, 8], {'canvas': [2174, 1404], 'matrix': [0, -1, 1, 0, 0, 1404]}]], [[[573, 2362, 8], {'canvas': [2362, 573], 'matrix': [0, -1, 1, 0, 0, 573]}], [[3240, 3198, 8], {'canvas': [3198, 3240], 'matrix': [0, -1, 1, 0, 0, 3240]}], [[2349, 3183, 4], {'canvas': [2349, 3183], 'matrix': [1, 0, 0, -1, 0, 3183]}], [[3672, 2107, 7], {'canvas': [2107, 3672], 'matrix': [0, -1, -1, 0, 2107, 3672]}], [[497, 2889, 6], {'canvas': [2889, 497], 'matrix': [0, 1, -1, 0, 2889, 0]}], [[1679, 3857, 0], {'canvas': [1679, 3857], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1194, 3699, 6], {'canvas': [3699, 1194], 'matrix': [0, 1, -1, 0, 3699, 0]}], [[3117, 2247, 8], {'canvas': [2247, 3117], 'matrix': [0, -1, 1, 0, 0, 3117]}]], [[[3582, 1031, 8], {'canvas': [1031, 3582], 'matrix': [0, -1, 1, 0, 0, 3582]}], [[2823, 328, 8], {'canvas': [328, 2823], 'matrix': [0, -1, 1, 0, 0, 2823]}], [[2580, 3384, 7], {'canvas': [3384, 2580], 'matrix': [0, -1, -1, 0, 3384, 2580]}], [[1742, 3974, 6], {'canvas': [3974, 1742], 'matrix': [0, 1, -1, 0, 3974, 0]}], [[2878, 1614, 0], {'canvas': [2878, 1614], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1553, 978, 5], {'canvas': [978, 1553], 'matrix': [0, 1, 1, 0, 0, 0]}], [[2394, 1311, 0], {'canvas': [2394, 1311], 'matrix': [1, 0, 0, 1, 0, 0]}], [[1397, 2252, 8], {'canvas': [2252, 1397], 'matrix': [0, -1, 1, 0, 0, 1397]}]], [[[3353, 3003, 8], {'canvas': [3003, 3353], 'matrix': [0, -1, 1, 0, 0, 3353]}], [[715, 3871, 8], {'canvas': [3871, 715], 'matrix': [0, -1, 1, 0, 0, 715]}], [[1728, 2634, 3], {'canvas': [1728, 2634], 'matrix': [-1, 0, 0, -1, 1728, 2634]}], [[2618, 2128, 9], {'canvas': [2618, 2128], 'matrix': [1, 0, 0, 1, 0, 0]}], [[2422, 1413, 3], {'canvas': [2422, 1413], 'matrix': [-1, 0, 0, -1, 2422, 1413]}], [[3842, 908, 7], {'canvas': [908, 3842], 'matrix': [0, -1, -1, 0, 908, 3842]}], [[1888, 3423, 4], {'canvas': [1888, 3423], 'matrix': [1, 0, 0, -1, 0, 3423]}], [[2003, 798, 8], {'canvas': [798, 2003], 'matrix': [0, -1, 1, 0, 0, 2003]}]], [[[2368, 85, 8], {'canvas': [85, 2368], 'matrix': [0, -1, 1, 0, 0, 2368]}], [[1473, 484, 8], {'canvas': [484, 1473], 'matrix': [0, -1, 1, 0, 0, 1473]}], [[663, 894, 6], {'canvas': [894, 663], 'matrix': [0, 1, -1, 0, 894, 0]}], [[2083, 1309, 2], {'canvas': [2083, 1309], 'matrix': [-1, 0, 0, 1, 2083, 0]}], [[318, 2513, 3], {'canvas': [318, 2513], 'matrix': [-1, 0, 0, -1, 318, 2513]}], [[2840, 2668, 9], {'canvas': [2840, 2668], 'matrix': [1, 0, 0, 1, 0, 0]}], [[3326, 1192, 2], {'canvas': [3326, 1192], 'matrix': [-1, 0, 0, 1, 3326, 0]}], [[1575, 215, 8], {'canvas': [215, 1575], 'matrix': [0, -1, 1, 0, 0, 1575]}]]]
labels = ["regression: tag 8 translation", "repair trap", "combined fault", "control", "control", "boundary", "boundary", "control"]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check("%s %d" % (labels[i % len(labels)], i), solve(args), expected)
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
regression: tag 8 translation 0{'canvas': [891, 1435], 'matrix': [0, 1, -1, 0, 0, 1435]}{'canvas': [891, 1435], 'matrix': [0, -1, 1, 0, 0, 1435]}Failed
repair trap 1{'canvas': [2696, 2552], 'matrix': [0, 1, -1, 0, 0, 2552]}{'canvas': [2696, 2552], 'matrix': [0, -1, 1, 0, 0, 2552]}Failed
combined fault 2{'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}{'canvas': [3307, 2787], 'matrix': [-1, 0, 0, -1, 3307, 2787]}Passed
control 3{'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}{'canvas': [2954, 1709], 'matrix': [1, 0, 0, 1, 0, 0]}Passed
control 4{'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}{'canvas': [58, 1879], 'matrix': [-1, 0, 0, -1, 58, 1879]}Passed
boundary 5{'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}{'canvas': [2834, 740], 'matrix': [1, 0, 0, 1, 0, 0]}Passed
boundary 6{'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}{'canvas': [1990, 1071], 'matrix': [1, 0, 0, -1, 0, 1071]}Passed
control 7{'canvas': [2174, 1404], 'matrix': [0, 1, -1, 0, 0, 1404]}{'canvas': [2174, 1404], 'matrix': [0, -1, 1, 0, 0, 1404]}Failed

SHA-256 / d8676ce220d77cff64ebb4f3c80d604cb8e9f6d65d54928e9d93662a2be333a5

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 8 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

A deterministic bounded teaching model with a stipulated contract; it makes no claim of conformance to any published specification. 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 2026-09-29T14:49:42.144803+00:00.

Case digest / 898c7f10e9f5c66bb56c5f9d0409302e5dc047a4df09a5868444765ca3445a70