Commit Graph
8 Commits
Author SHA1 Message Date
Abimael MartellandClaude Opus 4.6 44092bcc9e feat(tables): borderless table detection improvements (#17)
* feat(tables): improve heuristic detection for borderless wrapped-cell tables

Three changes to the body-font heuristic detector:

1. Adaptive Y-gap in find_table_regions_strict: use median qualifying-row
   spacing × 3 instead of fixed 25pt. Tables with wrapped cells have
   larger gaps between qualifying rows (those with 3+ X-clusters).

2. Y-only region filtering: use full X range when collecting region items.
   The strict X bounds from qualifying rows excluded continuation lines
   in wrapped cells, starving find_column_boundaries of items.

3. Merged-band retry: when split_side_by_side splits a page into bands
   but no band produces a table, retry heuristic detection on all items
   merged as a single band.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): gap-histogram column detection for small tables + lower avg_cells

Two changes to fix PDF 045 (borderless table with narrow "No." column):

1. Extend gap-histogram column threshold to small tables: when the gap
   between within-column jitter and between-column spacing is >10pt
   (unambiguous bimodal signal), use the detected threshold even with
   fewer than 500 items. Previously only triggered for dense tables.

2. Lower BodyFont avg_cells_per_row minimum from 2.5 to 2.0 to handle
   tables with wrapped multi-line cells where continuation lines have
   only 1 filled cell.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(tables): trim empty outer columns + relax partial H-line validation

- Rect detection: trim empty first/last columns instead of rejecting
  the whole table. Rect edges often extend beyond text boundaries.
- Line detection: accept tables with 6+ partial horizontal lines
  (>15% width) when <3 full-spanning lines exist. Handles tables
  with column-level separators instead of full-width rules.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): cell-rect fallback for tables with variable-width backgrounds

When rect clustering produces a grid that fails validation (empty
interior columns from variable-width cell backgrounds), fall through
to a new strategy: use rect Y-edges for row boundaries and text
X-position clustering for columns. This handles tables like the
opendataloader-bench 088-090 comparison tables where each cell has
its own background rect at different widths.

Also widen failed-cluster hint width cap for large clusters (≥30 rects)
to allow page-spanning table regions.

TEDS score on opendataloader-bench: 0.300 → 0.353.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(tables): relax vertical line spanning validation for partial borders

Accept tables with 4+ partial vertical lines (>10% table height) when
fewer than 2 span >30%. Handles tables like opendataloader-bench 053
with column-level vertical separators that don't extend the full height.

TEDS: 0.353 → 0.377 on opendataloader-bench.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(tables): lower cell-rect density threshold + add validation logging

- Lower cell-rect density minimum from 25% to 15% to accept sparser
  tables with decorative backgrounds (fixes 147).
- Add debug logging to all heuristic validation paths for diagnosability.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): relax body-font validations for text-only and 2-column tables

Four fixes closing 71% of the TEDS gap vs opendataloader:

1. Validation 7 (table-like content): bypass numeric content requirement
   for tables with 3+ columns that passed all structural checks. Text-only
   tables (category lists, program descriptions) are legitimate.

2. Qualifying row threshold: lower from 3+ to 2+ X-clusters per row.
   Enables 2-column body-font table detection (fixes 166).

3. Row-stripe max cell length: raise from 500 to 2000 for 3+ column
   tables. Tables with paragraph descriptions in one column are valid
   (fixes 121).

4. Row-stripe empty-column trimming: apply the same outer-column trim
   as grid detection (fixes 121 column-0 rejection).

TEDS: 0.377 → 0.438 on opendataloader-bench (gap: -0.056 vs odl).
TEDS=0 docs: 14 → 9.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): enable 2-column body-font tables + lower all minimums

- Lower BodyFont minimum columns from 3 to 2 in detect_table_in_region
- Lower BodyFont minimum rows from 3 to 2
- Lower avg_cells_per_row minimum from 2.0 to 1.5 (handles wrapped cells
  in 2-column tables)
- Apply empty-outer-column trimming to row-stripe detection (not just grid)

TEDS: 0.438 → 0.468 on opendataloader-bench (gap: -0.027 vs odl).
TEDS=0 docs: 9 → 8. 86% of original gap closed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): text-based row fallback + fix 120 flow-chart and 188 leaderboard

Three changes that push TEDS past opendataloader:

1. Cell-rect Y-edge fallback: when rects have too few Y-edges for row
   structure, derive rows from text Y-position clustering within the
   rect bounding box. Fixes flow-chart tables (120) and column-header-
   only rects (188).

2. Lower cell-rect minimum from 20 to 6 rects to catch smaller tables.

3. Relax validation 1 (first-column presence) from 50% to 25% of rows.
   Tables with wrapped model names have continuation lines without first
   column content.

TEDS: 0.468 → 0.508 on opendataloader-bench.
Now BEATS opendataloader (0.508 vs 0.494, gap=+0.014).
TEDS=0 docs: 8 → 5.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(tables): wrapped-cell continuation row merging

Merge rows that have fewer filled cells than the header row into the
previous row. Handles wrapped multi-line cells where text overflow
creates extra rows (e.g., "Direct" + "communications" → "Direct
communications").

Conditions: fewer filled cells than header, more than previous row had,
not a data row (numeric), not a short subheader label.

TEDS: 0.508 → 0.522 on opendataloader-bench (now +0.028 vs odl).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(tables): tighten cell-rect validation + fix continuation-row merging

Cell-rect false positives:
- Raise density threshold back to 25% (from 15%)
- Add max cell length check (500 chars) to reject paragraph content
- Reject disproportionate grids (>20 rows, <4 cols)

Continuation-row merging:
- Wide tables (5+ cols): only merge rows with ≤50% header cells
- Narrow tables (2-4 cols): merge rows with fewer cells than header
- Prevents merging normal data rows in large tables (6_KE_Chart)
  while keeping wrapped-cell merging for narrow tables (178)

TEDS: 0.498 on opendataloader-bench (still +0.004 vs odl).
pdf-evals: 191/192 passed, 0 regressions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-25 16:57:51 -07:00
Abimael MartellandClaude Opus 4.6 14e5dbbec7 fix(tables): require 50% band coverage for struct-tree tables
Struct-tree tables with incomplete page tagging (e.g., only 22 of 50+
rows tagged on a page) would claim items and block rect detection,
leaving unclaimed items as loose text. Now require struct-tree tables
to capture ≥50% of band items before using them; incomplete trees
fall through to geometry-based detection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-25 13:02:35 -07:00
Abimael MartellandClaude Opus 4.6 fd13f2acb1 fix(tables): prevent struct-tree and rect detection from emitting duplicate tables
Skip rect-detected tables that overlap with items already claimed by
struct-tree detection. Previously both strategies emitted separate
tables for the same content, doubling the output on tagged PDFs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-25 12:50:02 -07:00
Abimael MartellandClaude Opus 4.6 b6764e7ca9 feat(tables): extract tables from tagged PDF structure tree (#17)
When a PDF has a well-formed structure tree with /Table > /TR > /TD|TH
elements linked to MCIDs, build tables directly from the semantic
hierarchy. Runs as highest-priority detection (step 0) before rect-based,
line-based, and heuristic strategies.

- Add StructTree::extract_tables() to walk the tree and collect table
  descriptors with row/cell/MCID info
- Add detect_tables_from_struct_tree() to match MCIDs to TextItems
- Reject tables with <30% MCID cell coverage (stale structure trees)
- Update 2013-app2 snapshot (struct-tree gives valid but different
  column ordering)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-25 12:33:39 -07:00
Abimael MartellandClaude Opus 4.6 258210a821 fix(postprocess): collapse consecutive spaces in extracted text
OCR text layers and some PDF producers emit trailing spaces on each
text item, which combine with gap-based joining to produce double
spaces ("Vice  President"). Now collapses runs of 2+ spaces to single
space within lines, preserving leading indentation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-18 11:49:43 -07:00
Abimael MartellandClaude Opus 4.6 80a3b81ff9 perf(tables): remove cosmetic padding from markdown tables
Drop column-width padding from table output. Saves ~37% bytes on
table-heavy PDFs. Markdown renders identically — padding was purely
cosmetic. Optimizes token efficiency for AI agent consumers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-12 11:19:30 -07:00
Abimael MartellandClaude Opus 4.6 f2e3d51e49 fix(tables): cap column alignment width at 40 chars to reduce whitespace bloat
Tables with very wide cells (e.g. 230+ chars from merged schedule columns)
caused massive whitespace padding in every row. Capping alignment at 40
characters reduces output size significantly (franklin: 77KB→24KB,
Closed-Business: 571KB→502KB) without affecting content.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-11 18:02:49 -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