2b54ac2054
A second falsification: L2's squarings rounded instead of truncated still regenerated the corpus (the variant differs on about 3 in 100000 mantissas). vectors.json now states the SHA-256 of L2 at 2^18 spread values, of E2's mantissa for every fraction and of tan for every angle; both implementations check them. Co-Authored-By: Claude Opus 5.5 <[email protected]>
45 lines
2.7 KiB
Markdown
45 lines
2.7 KiB
Markdown
# live-conformance/tonemap — exact tone mapping
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The corpus of [`extensions/exact-tonemap.md`](../../extensions/exact-tonemap.md) §10:
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- `vectors.json`:
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- `frames`: the five frames of the `int_video` clip as `wai.video.int_motion` decodes them,
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in `frames.rgb8` (each `RGB8`, 48 × 48, one after another), the content hash (`object`) of
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the envelope `video` that carries the clip with its ST 2094-50 companion, the clip's payload
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(`source`, below `wai/`) and the sidecar that publishes each frame's SHA-256 (`sidecar`);
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- `envelopes`: each envelope's `name`, its `file` and its `content_hash`
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([jwp-receipts](../../extensions/jwp-receipts.md) §2.1);
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- `envelope_cases`: an envelope and the code SPEC §7.1's component rules give it (`role`;
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`null` where every component conforms);
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- `cases`: each its `records` in order as JSON texts, what the verifier `held` (the
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`envelopes`, by name; the `frames` file, or `""` for none), its `policy` (§8.1) and its
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`expect`ed outcome;
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- `arithmetic`: `L2` (`l2`, `[v, L2(v)]`), `E2` (`e2`, `[y, p, e]`), the table S (`srgb`),
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`tan` (`tan_q30`, `[θ, m]`) and the video's curves with their slopes (`slopes`), each at the
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points stated, and the SHA-256 of each over a whole range (`l2_sha256`: L2 at v = 1 + (k ·
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2654435761 mod 2^40) for k from 0 to 2^18 − 1; `e2_sha256`: E2's mantissa p for every
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fraction 0 to 65535; `tan_sha256`: tan for every angle 0 to 36000; each value as 8 bytes,
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little-endian, two's complement); large integers are written as decimal strings;
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- `measurement`: §6's figures, per derivation.
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- `envelopes/*.wai`: the envelopes, `WAI2` but for `gainmap-as-wai1.wai`.
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- `frames.rgb8`: the frames above.
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**Tone-map equivalence.** For each case, a conforming verifier reaches the outcome it states:
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- `refuse`: the `reason` of §9 and `at`, the record (`["record", i]`) or picture (`["record", i,
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"picture", j]`) refused;
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- `accept`: the `statements` of §8.3, one per record, exactly as written.
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A verifier that reaches another outcome, reason, place or statement does not conform.
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**Provenance.** `wai_tonemap_vectors gen` writes every file here. The stills are generated: two
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HDR scenes written as integer formulas in the generator (a sky with a sun six times reference
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white and coloured patches, one past white; a dim room with a window and a lamp), rendered to an
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sRGB base and a gain map by the reference's own encoder, integer throughout. The video is the
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`int_video` clip of `wai-rs/tests/vectors/int_video/`, generated there (a disc over a gradient).
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Every key is SHA-256 of the corpus's label and an index, every time is a constant, and Ed25519
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signing is deterministic, so every file is the same bytes on every machine.
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```
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python3 -I ../tonemap_verify.py .
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```
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