fix(detect): Fix cross-hatch false positives and filter control chars#216
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mlissner wants to merge 3 commits into
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fix(detect): Fix cross-hatch false positives and filter control chars#216mlissner wants to merge 3 commits into
mlissner wants to merge 3 commits into
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Two fixes for garbled font encoding false positives: 1. Add minimum 4pt width/height to _is_x_hatch_drawing. Thin vertical margin lines (0.75pt wide) were passing the line-pair check and being treated as cross-hatch redactions. 2. Filter text containing non-whitespace control characters (< 0x20, excluding tab/newline/return). These indicate garbled font encoding that happened to avoid U+FFFD. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Verifies that thin vertical margin lines (~0.75pt) aren't mistaken for cross-hatched redactions, and that garbled text with control characters is filtered. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Extracts specific pages with compression. Supports comma-separated page numbers and ranges (e.g., --pages 0,5,10-15). Useful when source PDFs exceed the 5MB pre-commit file size limit. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
Fixes for false positives from garbled font encoding in this PDF, plus a new developer tool:
Cross-hatch minimum size — add 4pt width/height check to
_is_x_hatch_drawing. Thin vertical margin lines (0.75pt wide) were passing the line-pair check and matching text on the page as "cross-hatched redactions."Control character filter — filter text containing non-whitespace control characters (
\x11,\x13, etc.) infilter_redactions_by_text. Real text never contains these — they indicate garbled font encoding that happened to avoid the U+FFFD replacement character.tools/trim-pdf.py— new tool to extract specific pages from large PDFs with compression, for creating test assets that stay under the 5MB pre-commit limit. Supports comma-separated pages and ranges (e.g.,--pages 0,5,10-15).Test plan
test_thin_margin_lines_not_cross_hatchesverifies both fixes with real-world PDFbad_cross_hatched_redactions.pdf(16 redactions)🤖 Generated with Claude Code