* fix(lib): detect substitution-cipher garbled text from broken ToUnicode CMaps
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>
* chore: bump pdf-inspector to 0.1.4, npm package to 1.9.11
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* fix(lib): exempt uniform-case structured content from cipher detection
Address PR review (cubic P2): the frequency branch (english_cosine < 0.60)
fired on any Latin-dominant, low-vowel letter distribution unlike English,
so non-linguistic ASCII — DNA/protein sequences, ticker symbols, hex dumps —
could be suppressed and routed to OCR despite not being garbled. Measured:
DNA cosine 0.428 / vowel ratio 0.260, protein 0.738, tickers 0.747, hex
0.549 — all would have flagged.
Add a mixed-case guard to looks_garbled: garbled English is a permutation of
natural language and carries sentence capitalization (block-straddling shifts
invert the ratio — att10k is 60% uppercase; in-case Caesar shifts preserve it
at ~3%), so both keep some of each case. The exempted structured content is
uniform case (all upper or all lower). Requiring the minority case to be >=1%
of ASCII letters exempts single-case sequences while preserving both garble
signals, including the in-case-shift scenario the frequency branch exists for.
Strictly tightens the detector: it can only remove flags, so the eval corpus
stays at zero false positives (verified byte-identical to a baseline main
binary across all 185 PDFs) and att10k remains flagged. Adds regression tests
for DNA, protein, tickers, and an in-case Caesar shift.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* fix(lib): make cipher detection case-agnostic via sorted-histogram shape
Address PR review follow-up: the mixed-case guard from the previous commit
returned before the vowel/frequency checks, creating a blind spot — a
uniform-case (all-lower or all-upper) substitution cipher is a plausible
broken-CMap output and would bypass OCR entirely.
Replace the case proxy with the actual invariant. A substitution cipher is
a bijection over a real language's alphabet, so it preserves the frequency
SHAPE (the sorted histogram) while scrambling letter POSITIONS (the unsorted
histogram). Signal 2 now flags when english_cosine < 0.60 (positions unlike
English) AND english_shape_cosine >= 0.90 (profile is still English-shaped).
This is independent of case, so it catches all-lower, all-upper, and
case-straddling shifts alike.
The exempted structured content fails one half: DNA/hex dumps have too steep
a profile (shape cosine 0.74 / 0.81 < 0.90), while protein sequences, ticker
symbols and base64 are not sufficiently unlike English in position (unsorted
cosine 0.74 / 0.75 / 0.77 >= 0.60). All stay out of OCR.
Still strictly corpus-safe: every real Latin document scores unsorted cosine
>= 0.70 (min 0.80), far above the 0.60 gate, so none can reach Signal 2.
Re-verified byte-identical to a baseline main binary across all 185 eval
PDFs; att10k remains flagged. Drops the now-unused case counters and adds
all-lowercase / all-uppercase shifted-prose regression tests.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* chore: source Python package version from Cargo.toml via maturin
Address PR review (cubic P2): pyproject.toml pinned version = "0.1.0",
which overrides Cargo.toml, so a maturin build produced a 0.1.0 Python
artifact regardless of the crate version (it had drifted since the PyO3
bindings were added). Switch to dynamic = ["version"] so maturin sources
the version from Cargo.toml [package] version and the two can no longer
diverge. No workflow auto-publishes the Python package, so this is metadata
hygiene rather than a release-path fix.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
When a wire-bordered table has headers centered/right-aligned in their
cells but data left-aligned, cluster_x_positions can both merge adjacent
data columns (when the data-to-data gap is below the clamped threshold)
and drop the header-only x-positions in its singleton-filter pass. The
cell-rect fallback then used text-cluster column edges and lost a column
or fragmented neighbor cells.
Prefer rect-derived column edges when the rect grid has 3+ columns and
every rect column holds multiple text items. The all-cols-populated
check protects against decorative or background rects (prose laid out
in a frame, cell-fill rects with extra borders) that would otherwise
split a logical column into spurious sub-columns. The existing
prose-in-frame, well-distributed-columns, and wireless-prose guards
still fire for the cases they were built for.
Bump napi version 1.8.7 → 1.8.8.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* tables: lift detection on shaded-header + alt-row tables (#wired-grids)
Production telemetry on `wired_high_confidence`-classified table regions
showed `detect_vector_grid_in_region_mem` returning a usable grid only
~27% of the time, with the rest falling through to GLM-OCR. Three
surgical fixes target the dominant production shapes:
* Path-fill cell backgrounds: when the page has no `re` rects but draws
cell backgrounds via `m`/`l`/`h`/`f*` sequences, prefer the fill-derived
rects over the few section-level `W*` clip paths that previously won
the priority gate. Activated when fill rects outnumber clip rects ≥3×.
* Dedup-induced cluster splits: page-background rects could pose as
containers in the sub-rect dedup and evict a slightly smaller
table-frame rect, breaking adjacency between column-cell groups so each
column became its own cluster. Origin-anchored containers are now
disqualified from sub-rect dedup. A separate exact-duplicate pass
collapses the cell-padding/text-bg/cell-border triple emissions some
PDFs produce, preserving original order to avoid reshuffling table
output on multi-table pages.
* Prose-words rejection: the `cell-rect` fallback's whole-grid prose
threshold also rejected real tables that include a description column.
Now relaxed when content is well-distributed (≥75% of cols filled),
while keeping the original strictness for prose-in-a-frame layouts.
Two regression fixtures from the opendataloader-bench corpus, covering
the dominant production failure categories:
* `greencomp_competence.pdf` — 2-col shaded-header + plain-body glossary.
Mirrors production crops #1 (Contractions glossary) and #6 (BIO 350
course header).
* `upstage_key_functions.pdf` — 4-col shaded-header + alt-row backgrounds
+ merged left column. Mirrors production crops #2 (Parameter/Value
alt-row), #7 (Spanish XML schema), and #8 (Córdoba multi-row header).
Existing fixtures stay green (doc 51 wrapped-label, doc 128 forecast
six-cols, td9264 snapshot). 133 unit + integration tests pass; clippy
clean.
Bumps napi/package.json 1.8.4 → 1.8.5.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* tables: tighten prose-in-frame rejection — fixes pdf-evals #30 regression
PR #76's shaded-header detection lift surfaced a regression on
accessory_building_permit_application_1 (TEDS 0.10 → 0.05): a
paragraph of legal text laid out in a 2-column justified block was
being admitted as a 10×2 fake table where every cell holds a
sentence fragment ("I agree to comply...", "I", "It is the property
owner's responsibility..."). Per pdf-evals PR #30 review, this is
the kind of regression production users will notice — the markdown
is structurally and semantically misleading.
Root cause: PR #76's prose-rejection only fires for `num_cols >= 4`,
so the 2-col prose-in-a-frame case slipped past it entirely. The new
fill-priority + dedup changes started producing rects for this layout
that 1.8.4 correctly ignored.
Fix: tighten the prose-in-frame check.
- Lower the column-count guard from `>= 4` to `>= 2`.
- Add a content-length signal as the primary discriminator: when the
prose-words trigger fires AND mean non-empty cell length exceeds
65 chars, reject regardless of column distribution.
The 65-char threshold cleanly separates observed cases:
accessory_building (prose-in-frame): mean 74 chars → REJECT
upstage_key_functions (real 4-col table): mean 53 → admit
greencomp_competence (real 2-col glossary): mean 20 → admit
accessory_building (real 5×3 form data): mean 10 → admit
The well-distributed-cols relaxation that PR #76 added stays —
"label / value / description / benefit" tables (#7, #8 from the
production crops) still pass, but only when their mean cell length
stays below the prose threshold.
New regression test `accessory_building_rejects_prose_in_frame` asserts
both that the real 5×3 form data table survives AND the 10×2 prose
block is rejected. Snapshot test `test_snapshot_td9264` updated to
match new output — old snapshot captured the same prose-in-frame bug
on regulatory text (paragraphs emitted as 3-col `||text||` fake-table
rows). New snapshot emits clean prose paragraphs, which is correct.
Verification:
- cargo test --all: 424 lib + 133 integration + 2 doc tests pass
- cargo fmt --check clean
- cargo clippy -- -D warnings clean (lib-level; pre-existing
test-level clippy issues on the wired-grids branch unaffected)
- Existing fixtures stay green: forecast_table_chart_six_cols (PR
#72), bits_pilani_* (PR #73), greencomp_competence_two_cols and
upstage_key_functions_four_cols (PR #76).
This branch is based on abimaelmartell/wired-grids so it includes
PR #76's commits plus this fix on top. Suggest merging this and
closing #76, OR rebasing #76 to incorporate this fix.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* tables: drop early-dedup atom — caused broad TOC + matrix corruption
Bisected PR #76's 4 atoms against the SEC 10-K
0001104659-25-093871_183e44ac.pdf which appeared as a TEDS regression
in pdf-evals PR #30. Result:
atom | TOC | perf-graph | qualifications
---------------------------|-----|------------|---------------
fill-priority | ✓ | ✓ | ✓
early-dedup | ✗ | ✗ | ✗
page-bg disqualification | ✓ | ✓ | ✓
prose-relaxation | ✓ | ✓ | ✓
Early-dedup was the SOLE source of all three regressions on this doc.
Tried a more conservative variant (≥3 copies only — pair-duplicates
appear in legit multi-section layouts like 10-K dividers above + below
section headers); didn't fix the regression. The triplet+ duplicates
on this doc are real, intentional rects, not the cell-border + inner-
fill + text-bg pattern PR #76 was targeting.
Drop early-dedup. Mark `greencomp_competence_two_cols` as #[ignore]
since that wired-grid lift only worked WITH early-dedup; a more
surgical lift in `try_build_grid` / `snap_edges` for the
cell-border + inner-fill + text-bg triplet pattern is the right
follow-up. The other PR #76 wins (upstage_key_functions / production
crops #2, #7, #8) still hold; greencomp / production crops #1, #6
revert to GLM until the surgical fix.
Validation on the regression doc:
0001104659 TOC PART II markers: 4 (matches main, was 2 with PR#76)
0001104659 perf-graph data row: 2 (matches main, was 1)
0001104659 qualifications rows: 9 (matches main, was 6)
Validation on the prose-frame doc:
accessory_building fake-table: 0 (matches main, was 1 with PR#76)
accessory_building prose intact: 1 (matches main)
cargo test --all clean, cargo fmt --check clean, cargo clippy --lib
-- -D warnings clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* fix: improve heuristic table detection for numeric columns and multi-line headers
Two fixes for tables that have clean extractable text but fail heuristic
structure detection:
1. Numeric column merge pass (grid.rs): After initial X-position
clustering, adjacent clusters are merged when one is sparse (header
text) and the other is dense with >50% numeric items (data column).
Multi-line wrapped headers often land slightly offset from their
data column — the merge closes gaps within 1.5× the clustering
threshold. New is_numeric_text() helper matches decimals, percentages,
negative numbers, and comma-separated thousands.
2. Duplicate-header skip (detect_heuristic.rs): Spanning super-headers
like "First Degree | First Degree | Higher Degree" contain duplicate
cells that trigger looks_like_partial_table_ex rejection. Now skips
rows with duplicate cells when a better header candidate exists
within the next 3 rows (higher fill ratio or numeric cells).
Tested on BITS Pilani university report (430 pages, 314 table pages).
Page 4 (multi-line header + numeric data) previously returned
needs_ocr=true; now correctly detects the table structure.
Eval: 197 PDFs, zero regressions, all 104+ tests pass, zero clippy.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* bump version to 0.7.1
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
PDFs that embed landscape content in portrait pages via a rotated text
matrix (e.g. [0, b, -b, 0, tx, ty] for 90° CCW) produced garbled output
because the layout engine assumed x=horizontal, y=vertical.
Track the dominant text direction from combined matrices during extraction.
When ≥67% of text operators are rotated, swap x↔y coordinates (with
y-negation for correct reading order) for all text items, rects, and lines.
Also estimate text widths from char count × font size since scale_x ≈ 0
for rotated text.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
When Identity-H or Type3 fonts lack a ToUnicode CMap and the
CID-as-Unicode passthrough doesn't produce valid text, the raw CID
byte values appear as mojibake (random Latin Extended characters mixed
with C1 control codes).
The detector already flags these pages in pages_needing_ocr, but the
markdown pipeline still emitted the garbage. Now, for TextBased PDFs,
we check each OCR-flagged page's extracted text for CID garbage
(C1 control characters U+0080–U+009F at ≥5% density) and strip items
from pages that fail the check.
This is scoped to TextBased PDFs only — Mixed PDFs flag pages for OCR
due to template images, not font encoding issues.
Adds test fixture (shinagawa_identity_h.pdf) and integration test.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
* feat: tagged PDF structure tree support for semantic markdown generation
Parse /StructTreeRoot from tagged PDFs and use semantic roles (H1-H6, P,
LI, BlockQuote, Code, Caption) to improve markdown output. Structure tree
headings add to font-size heuristics without suppressing them. Coverage
threshold (≥50%) ensures only properly tagged PDFs activate this path.
Phase 1: Parse structure tree with role maps, MCID collection, flattening
Phase 2: Capture MCIDs from BMC/BDC operators, tag TextItems
Phase 3: Structure-aware markdown generation in convert loop
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* fix: accumulate consecutive code lines into single fenced block
Per-line code fencing produced broken markdown for multi-line code
blocks (separate ``` open/close per line). Unify struct-tree Code
role and font-based monospace detection into a single is_code_line
check with in_code_block state for proper accumulation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* test: add tagged PDF fixture with Firecrawl docs content
Synthetic 7-page PDF with rich structure tree exercising H1, H2, H3,
P, Code, LI, Caption, TH, TD roles. Generated via fpdf2 script.
Integration test verifies struct tree parsing and code fence output.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* chore: remove python PDF generator script from repo
Keep the generated fixture PDF but don't track the generator script.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* fix: handle malformed bare-name struct types in tagged PDFs
Some PDF generators (e.g. fpdf2) write /S Code instead of /S /Code
in structure elements. lopdf silently drops these objects since bare
tokens are invalid PDF syntax. Add a pre-processor that scans for
known bare struct type names and prepends / before loading.
Unifies path and memory loading through the same fix pipeline.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* chore: update lopdf dependency to main branch
The firecrawl/zlib-checksum-encrypted branch was merged and deleted.
Point to main which includes all previously merged fixes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* chore: switch lopdf to upstream repo pinned at 845cd3d
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Unit test verifying short sub-header rows (e.g. month names) are not
merged as continuation rows in table formatting. Snapshot test for
2013_app2.pdf pinning the full row-stripe table output.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add 5 stripped public-domain PDF fixtures and golden markdown snapshots
for CI regression testing. Fix non-deterministic output caused by
HashMap iteration order in font stats, table heuristics, and rect
clustering by adding deterministic tie-breaking.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
