mirror of
https://github.com/storytold/vectorcraft.git
synced 2026-10-24 09:46:59 -06:00
When the Compression settings keep a PNG as it is, the PNG goes to the PDF writer unchanged, and the writer refuses images of 16 bits a sample below PDF 1.5. Saving a document with a placed 16-bit PNG as PDF 1.4, or as a .ai file at 1.4, failed with "PDF writer error: SixteenBitImage(...)" and wrote nothing. PDF 1.3 and PDF/X-3 failed the same way for an opaque 16-bit PNG, and PDF/X-1a failed for a 16-bit gray PNG. In PDF 1.3 and 1.4 files, such a PNG is now decoded and encoded again at 8 bits a sample, with the same color type and ICC profile, before the writer reads it. From PDF 1.5 on, it keeps its 16 bits. A 16-bit PNG whose pixel data can't be decoded is left out with the note "an image couldn't be decoded and is missing from the picture". Docs: docs/mcp.md (PDF options).