Grzegorz MartensandClaude Opus 5.5 ff8a07f283 M11: monochrome downsampling leaves halftones alone; bounds; an indexed tie under an inverting decode ...

- Halftones and dithers: most of their new pixels cover both black and
  white, and taking the sample that covers more turned their tones
  solid (a 50% screen black, a 25% one white). An image whose new pixels
  mostly cover both is now left at its resolution; text covers both only
  along its edges and is still averaged down. downsample_bits says how
  many new pixels cover both.
- A counter for each column: an image wider than a fax row
  (MAX_CCITT_COLUMNS) isn't averaged, so a strip of 80 million columns
  can't make the counters 640 MB.
- A fax image's decoding is bounded at about a byte a pixel, as
  redaction's is (decoded_image_within), not 1 GiB; behind a Flate bomb
  it is left alone.
- An indexed image's tie went to sample 0, which an inverting decode
  array maps to entry 1, though the docs say entry 0. It goes to the
  sample that decodes to entry 0 now (ISO 32000-2 §8.9.5.2).

Each has a test that fails without it.

From reviews with the pdfcraft-review skill.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P6yUtvWGPsJpMLyh6pxSXG

2026-10-29 20:48:03 +01:00

..

jpeg_color_transform.rs

style: rustfmt the cancellation test

2026-10-23 10:53:16 +02:00

optimize.rs

M11: monochrome downsampling leaves halftones alone; bounds; an indexed tie under an inverting decode

2026-10-29 20:48:03 +01:00