Huffman table from maker note 0x0220 (codes/lengths, black-box layout), T.81 difference categories, same-colour horizontal prediction with per-row-parity vertical seeds; BlackPoint, WB levels, maker-note image area or dark-column trimming. Unit round-trip test with our own table. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>