Commit Graph
6 Commits
Author SHA1 Message Date
Abimael MartellandClaude Opus 4.6 7c8b09be67 fix: improve table detection for numeric columns and multi-line headers (#35)
* 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

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Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 17:27:59 -07:00
Abimael MartellandClaude Opus 4.6 a199768c4e fix(layout): detect and correct rotated page text (#10)
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>
2026-03-23 12:14:44 -07:00
Abimael MartellandClaude Opus 4.6 aa387503c3 fix(fonts): suppress garbage CID text on OCR-flagged pages (#9)
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>
2026-03-23 10:35:45 -07:00
Abimael MartellandClaude Opus 4.6 d9c2143c32 feat: tagged PDF structure tree support (#4)
* 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>

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-17 20:50:24 -07:00
Abimael MartellandClaude Opus 4.6 1bacf34bd0 Add tests for row-stripe table detection
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>
2026-02-23 09:43:23 -08:00
Abimael MartellandClaude Opus 4.6 28313e1f2d test: Add snapshot regression tests with PDF fixtures
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>
2026-02-18 16:13:55 -08:00