Brandon ThomasandClaude Opus 5.5
72d640f9f0
A page's /Contents array is one content stream in pieces that writers may split between any two tokens (ISO 32000-2 §7.8.2). Edit text parsed each piece on its own, so an operator whose operands ended one piece and whose keyword started the next arrived with no operands: a `[(After) -20 (wards)]` / `TJ` split made the line vanish from text_lines, text_paragraphs and text_edit, and from the Edit text tool. The joined-parse logic the redaction interpreter used (#153) moves into pdfcraft-content as `Pieces`: join the pieces, parse them as one stream, map positions back to pieces, and splice joined byte ranges back into per-piece bytes (an edit replacing or removing an operator that spans pieces rewrites every piece it touches; untouched pieces keep their objects). text_lines now interprets the joined operators, and replace_line and rewrite_block splice through `Pieces`. Redaction uses the same helper. Lines and paragraphs are grouped by the piece their first operator starts in, as before, so pages whose pieces are separate drawings don't merge. Co-authored-by: Claude Opus 5.5 <[email protected]>
pdfcraft-redact
Layer L4 (may use edit): redaction, architecture §11.2.
// Marks are Redact annotations (pdfcraft-annot: Shape::Redact { quads, overlay }).
let marks: Vec<Mark> = marks(&doc); // page, areas (user space), fill, overlay text
let report = apply(&mut doc, None)?; // everything, or Some(&[pages])
clear_marks(&mut doc, None)?; // remove marks without applying
apply removes, under every marked area:
- text: glyphs are cut out of
Tj/TJ/'/"and replaced by aTJdisplacement of the same advance, so the rest of the line keeps its exact position. Widths come from/Widths,/W//DW(composite fonts, embedded CMaps with codespace and CID ranges), Type 3 font matrices, and approximations for the standard 14. A glyph goes when it overlaps an area by more than a fifth of its size (or a point) both ways; zero-size text goes when its origin is inside; - images: fully covered → removed; partly covered → a copy with the covered pixels cleared (8/16-bit and 1/2/4-bit images, image masks; Flate/LZW/RL/A85/AHx). Codecs PdfCraft can't re-encode (DCT, JPX, JBIG2, CCITT) are removed whole (fail-closed); inline images under an area are removed;
- vectors: covered paths are removed; partly covered paths and shadings are clipped so nothing paints inside the areas;
- form XObjects: rewritten recursively into new objects (pages sharing the original keep it);
- annotations whose rectangle overlaps (with their pop-ups), and form fields with a widget under a mark;
- the marks themselves, replaced by boxes in their fill colour (and overlay text) drawn into the
page as a
/PCMark /Redactionstream.
A verification pass re-reads each redacted page and fails the operation if any glyph or inline image is still under an area. Content that can't be decoded makes the operation fail rather than leave it unredacted.
Remove hidden information / Sanitize
let found = sanitize::scan(&doc); // [(Hidden, count)] per category
sanitize::remove_hidden(&mut doc, &[Hidden::Comments])?; // chosen categories
sanitize::sanitize(&mut doc)?; // all of them
Categories: metadata (/Info, XMP), file attachments, comments, form fields (flattened so the
values stay visible), hidden text (render modes 3 and 7, or wholly off the page), hidden layers
(content of off optional-content groups, then the groups), bookmarks, links/actions/JavaScript,
and /PieceInfo private data. Both make the next save a full rewrite.
patterns finds phone numbers, e-mail addresses, credit card numbers (Luhn-checked), US Social
Security numbers and dates for Search & Redact.
Not yet: pattern locales, struct-tree/alt-text cleanup, metadata and hidden-information sanitising (M8.4), re-encoding of DCT images (they are removed instead).