ParseBench text_simple__att10k.pdf (issue #118) ships Type0/Identity-H
fonts whose ToUnicode CMaps are authored garbled: every bfrange maps with
a wrong constant delta, so text extracts as pure-ASCII ciphertext
("Certificate" -> "8VceZWZTReV"). The embedded subset font has no cmap
table and no glyph names, so no decode source can recover the real text
(poppler and mupdf emit the same ciphertext). The only correct behavior
is to flag the page for OCR instead of serving the garbage silently --
but the text is 100% printable ASCII with word-like tokens, so it slipped
past is_garbage_text and detect_encoding_issues.
Add CipherGarbleStats, a letter-statistics discriminator that flags a
Latin-dominant sample (>=200 ASCII letters) when vowels are starved
(<=30% of letters) AND either:
- lowercase->uppercase transitions inside words exceed 10% of letter
bigrams (a shifted lowercase alphabet straddles the ASCII uppercase
block), or
- the letter histogram's cosine similarity against English letter
frequencies drops below 0.60 (catches shifts that stay within case
blocks).
Wired into analyze_text_quality (per-page, item-level) and
detect_encoding_issues (markdown-level), so extract_pages_markdown
reports needs_ocr + suspected_garbled_text and suppresses the garbage.
Thresholds validated against the 380-document pdf-evals snapshot corpus
(Swedish, Finnish, Turkish, German, romaji, schematics, all-caps and
camelCase-heavy docs): zero false positives, and byte-identical eval
output vs main. Garbled page measures vowel ratio 0.245 / case-shift
rate 0.225 / cosine 0.532; closest legitimate document on each axis is
0.264 / 0.021 / 0.801.
Fixes#118
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* feat(markdown): underline emission, Unicode scripts, style-preserving merges (ENG-5015 2b)
Three formatting losses in the direct-extraction markdown path:
1. text_with_formatting gains <u> run emission (detect_underline option,
default on) using the geometric is_underline flag from 1.9.9.
Underline runs stay free of nested bold/italic markers — consumers
match tag content literally. Heading lines keep plain text for
bold/italic but preserve <u>: the tag carries meaning `#` doesn't.
2. merge_subscript_items now maps absorbed digit scripts to Unicode
sub/superscript forms with direction from the baseline offset
("H"+"2" -> "H₂", "word"+raised "2" -> "word²", "m"+"3" -> "m³").
NFKC/NFKD folds these back to plain digits so text matching
downstream is unaffected; renderers keep the script semantics.
3. merge_text_items no longer merges across bold/italic boundaries —
absorbing a styled run into a plain neighbor erased the styling
before markdown emission ever saw it. On eval docs this recovers
20-82 italic runs per document that previously emitted as plain.
Snapshots regenerated (diffs are the features: CCl₂F₂, m³, underlined
legal section headings, finer bold runs). pdf-evals regression suite:
202/202 real PDFs pass. napi 1.9.9 -> 1.9.10.
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix(extractor): break merges at underline boundaries too (review)
OR-merging underline stretched the eventual <u> span over neighboring
plain fragments. Merge runs now break on any style-flag change, the
redundant accumulator is gone, and format_list_item learned to move
bullet markers outside <u> wrappers so fully-underlined bullet lines
still render as markdown lists. td9264 snapshot regenerated — spans are
tighter (trailing periods correctly outside the tag).
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix(markdown): strip stray spaces before sentence punctuation (review)
Style-boundary item splits can strand a trailing period in its own
fragment, and multiple assembly paths join fragments with spaces,
yielding "word ." artifacts. Rather than chasing every join site, a
postprocess pass removes a space before `.`/`,`/`;` when the mark ends
its token (whitespace, cell boundary `|`, or end of text follows).
Dot leaders/ellipses and mid-token periods are untouched.
Fixes the td9264 "companies ." artifacts and two pre-existing
"armoring ," artifacts in the 2013-app2 snapshot. pdf-evals: zero
markdown diffs across all 203 corpus PDFs vs committed baselines.
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix(tables): trim spaces inside parenthetical cell fragments
* fix(tables): reject sparse prose row-stripe tables
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Co-authored-by: Cursor <cursoragent@cursor.com>
* feat(extractor): geometric underline detection on TextItem (ENG-5015)
PDFs carry no underline font flag — underlines are stroked horizontal
lines or thin filled rects drawn under the baseline. Correlate those
graphics (already parsed from the content stream) with text items in a
post-pass: a rule within ~0.35em below the baseline covering >=60% of
an item's width marks is_underline.
Exposed through the napi and python bindings. Verified on real docs:
4/4 underlined sentences flagged on a Japanese report, links/headings
flagged on 8 of 10 underline-bearing eval docs, zero flags on docs
without underlines. Known FP source (table cell borders) documented —
downstream applies inline styling only to plain-text regions.
napi 1.9.8 -> 1.9.9.
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix(extractor): underline rules only from painted rects, normalized extents (review)
Two review fixes: (1) normalize rect extents before the thickness/width
checks — `re` operands pass through the CTM so width/height can be
negative, which missed negative-width rules and let negative-height
bands pass as thin; (2) only feed painted rects to underline detection —
`re` rects now wait in a pending list until a paint operator (S/s, f/F/
f*, B/B*/b/b*) confirms them, and `re W n` clip-only paths are discarded
at `n`, so invisible clip boundaries no longer underline nearby text.
Marking moved into content_stream where paint state lives (pre-rotation,
consistent device space).
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix(extractor): harden underline detection
* feat(cli): export positioned text item json
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Co-authored-by: Cursor <cursoragent@cursor.com>
