Commit Graph
2 Commits
Author SHA1 Message Date
Morten Husted Lochmann f280ca8e6d M10: exported TIFF and JPEG pages record the resolution they were drawn at (#3332)
* M10: exported TIFF and JPEG pages record the resolution they were drawn at

A page exported as TIFF said 1 x 1 with no unit, whatever the dpi, and
a JPEG export said nothing, so other programs showed and printed them at
a default (a 300-dpi page shown at 72 dpi is four times too big).
encode_image now takes the dpi: TIFF X/YResolution in inches, the JFIF
density in dots per inch.

PNG stays without pHYs. It counts pixels per metre, so 72 dpi would read
back as 72.009, and a page made from an exported PNG (doc_create from
images, as enhance_camera_image_through_tools does) would come out 0.01%
small.

Exporter records the resolution a page was actually drawn at (dpi_used),
so a page too large for the renderer says the lower one. render records
--dpi, since it refuses oversized pages. The TIFF is written with the
tiff crate, already in the graph, because image's TiffEncoder can't set
a resolution.

* M10: TIFF page exports are LZW-compressed, as documented

encode_tiff's comment said "LZW-compressed by the encoder's default",
but the TIFF was written uncompressed: a Letter page at 300 dpi came to
25 MB. It is now LZW without a predictor, the compression TIFF readers
support most widely after none.

* Contributors: add my name for the About window
2026-10-18 17:06:41 -04:00
505c4a2fa3 Issue #248: pdfcraft-cli render writes the format its --out name says (.png, .jpg, .tif or .pam) (#255)
`render --out p1.png` wrote a netpbm PAM stream (P7) whatever the name,
so a `.png` could not be opened by any PNG reader. The CLI already links
the engine, whose export module encodes PNG, JPEG and TIFF, so the output
format now follows the extension: `.png`, `.jpg`/`.jpeg` (quality 90),
`.tif`/`.tiff`, and `.pam` for the raw stream as before. Any other name
is refused up front, before the page is rendered, with the accepted list.

`export::encode_image` wraps the three encoders behind `ImageFormat` so
the CLI and `Exporter::image` share one match.

Tests (apps/pdfcraft-cli/tests/render.rs): a `.png` gets the PNG
signature and an IHDR with the rendered size; `.JPG` and `.tif` get
JPEG/TIFF magic; `.pam` still gets the P7 header and the right number of
bytes; `.bmp` fails with the message and writes nothing.

Co-authored-by: wstock <1394687+wstock@users.noreply.github.com>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-08 07:25:43 -04:00