Commit Graph

3 Commits

Author SHA1 Message Date
bflatastic ac77b52ad3 M4.49: PNG-8 and GIF export with a palette quantizer and dithering
document.export {format: "png8" | "gif"} reduces the art to a palette of at most `colors`
(2–256) entries: median cut over a 15-bit histogram refined by k-means (perceptual,
selective or adaptive weighting), or the web-safe, black-and-white or grey palettes; art
with that many colours or fewer keeps them exactly. Dithering is Floyd–Steinberg diffusion,
an 8×8 ordered pattern or noise, with an amount. Pixels under half opacity become one
transparent entry; partly transparent edges blend over the matte. PNG-8 is an indexed PNG
(PLTE, tRNS, 1–8 bits per pixel, Adam7); GIF is a GIF89a (optionally interlaced). Both are in
document.formats, Export As (PNG-8 / GIF Options dialogs) and Export for Screens.
document.formats' writable list and the MCP export tool's format enum gain gif and png8
(their tests list them).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 11:26:15 +07:00
bflatastic 6a446b4fa3 M4.55: File Info with author, description, keyword chips, rating and copyright, written to SVG, PDF and PNG
file.info takes and reports the title, author, author title, description,
keywords, rating, copyright status, notice and URL in one undo step, plus
the read-only created (file.new) and modified (every save to a file) dates;
junk values are refused. Document.metadata (DocMetadata) round-trips
natively. PDF export writes author, subject and keywords to the info
dictionary and XMP, PNG export writes tEXt/iTXt chunks, SVG export writes
<desc> and, with the metadata option, every field as Dublin Core. The File
Info dialog (fileInfo, ui.fileInfoDialog) edits it with keyword chips and
star ratings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 09:55:47 +07:00
bflatastic 157724279f M4.34: raster export options and PNG Options — resolution, background, anti-aliasing, interlacing
PNG is written by an in-code chunk writer with the resolution in pHYs and optional Adam7
interlacing (JPEG stores the resolution in JFIF). document.export takes ppi (72/150/300/other,
wins over scale), background (transparent, white, black or a colour) and antiAlias (none, art,
type: text snapped to whole pixels); Export for Screens rows take them too (plus one top-level
antiAlias, and a row's ppi names its @Nx suffix), and so does object.rasterize. Hard edges stay
hard in every offscreen pass (groups, masks, filters), whatever the thread count.
RenderOptions.anti_alias and render::encode::RasterExportOptions; PNG/JPEG/WebP Options dialog
(pngOptions/jpgOptions/webpOptions) after File > Export As PNG.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 09:14:11 +07:00