The decoder tried each high-frequency band at its synthesis width and up to
two more columns, keeping the first width whose entropy stream ended exactly.
Two widths can both do that with different coefficients (#899).
Measured on every C-RAW plane in cr3_corpus.rs (CC0 raw.pixls.us files):
each band decodes at exactly one width. A tile with a neighbour on its right
codes bands 5 and 8 (the vertical high-pass of the level-2 and level-1
low-pass columns) at an odd width, so an even band gains one unused column;
no other band is extended. The width now comes from that rule, and a stream
that does not fit it is corrupt (the CR3 falls back to its preview).
All corpus sensor hashes are unchanged. The property-test encoder now codes
bands 5 and 8 the same way. Middle tiles (three or more C-RAW tiles) follow
the left-tile rule; no public file has one.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
