{
"schema_version": 1,
"differences": [
{
"id": "native-render-channel-tolerance-4",
"category": "render-tolerance",
"threshold": {
"channel_tolerance": 4,
"max_mismatch_pct": 0.8,
"max_mean_abs_diff": 0.2
},
"rationale": "IW44 / YCbCr rounding and filter differences versus DjVuLibre at native resolution; documented in tests/diff_tolerance.md and enforced by conformance/corpus.json."
},
{
"id": "colorbook-page0-ubuntu-3.5.28",
"category": "render-tolerance",
"fixture": "tests/fixtures/colorbook.djvu",
"page": 0,
"rationale": "Pinned Ubuntu DjVuLibre 3.5.28 reports ~0.75% mismatch on colorbook page 0; the gate uses max_mismatch_pct 0.8 so the published baseline stays fail-closed without silent skips."
},
{
"id": "metadata-meta-vs-print-meta",
"category": "semantic-source",
"rationale": "djvu-rs metadata() reads METa/METz first, then falls back to the (metadata ...) block of the DIRM shared-annotation component, the only source DjVuLibre print-meta reads (#833). czech.djvu covers the shared-annotation path; no corpus document carries METa/METz, which DjVuLibre ignores."
}
]
}