OCR Book Polisher

Use this skill for scanned or image-heavy books that need more than a hidden text layer: the output should read like a newly typeset book, with corrected text, real headings, figures, captions, and a reliable table of contents.

For technical books with equations, diagrams, tables, music notation, or dense figures, read references/pdf-to-tex-equation-figure-table-workflow.md before choosing the OCR route. For concrete tools, script responsibilities, and validation commands, read references/pdf-to-tex-toolchain-and-scripts.md.

Core Rules

• Fix the body, not only the generated TOC. If the TOC is wrong, locate the corresponding content heading and correct or insert it in the source text.
• Preserve images and captions when the original book contains meaningful figures. Remove placeholder prose such as “original page image” unless the user explicitly wants a facsimile.
• For equations, tables, diagrams, music notation, chord charts, staff notation, and exercise layouts, preserve the semantic object when possible; otherwise preserve the original visual object as a high-quality figure with clean caption and source evidence.
• Treat OCR as suspect until checked against source evidence. Correct obvious recognition errors, garbled Latin fragments, broken captions, and misread headings.
• Keep old outputs if requested, but put new editions in a clear folder such as build/<book>-polished-tex/ or build/<book>-booklike-pocket/.
• For PDF-to-TeX conversions, produce an exact/review edition before changing page size. Then generate the pocket edition from the same reviewed TeX body.
• Validate before claiming completion: generated PDF path, page count, TOC, log warnings, overfull lines, missing figures, text extraction, and a spot check of representative pages.

Workflow

1. Inventory sources and current artifacts:

git status --short
find sources books build -maxdepth 3 -iname '*BOOK*' -o -iname '*.pdf' -o -iname '*.md'

2. Extract or OCR into page-aware Markdown. Preserve page markers and page kind metadata, for example:

## Page 18
<!-- kind=text confidence=medium -->
### Chapter Heading
正文……

3. Build a real structural map from the source book:

• Use the original contents pages, title pages, and body starts.
• Map printed page numbers to physical/OCR page numbers.
• Insert missing body headings where chapters actually begin.
• Mark noisy OCR headings as local headings, not TOC entries.

4. Polish text page by page:

• Join broken paragraphs and restore punctuation.
• Correct OCR confusions by comparing neighboring context and source images.
• Rewrite captions into clean captions; do not drop captions silently.
• For figure pages, prefer full-page figures in pocket editions unless the layout requires otherwise.

5. Render TeX/PDF with a strict heading policy for fragile books. Only allow verified headings into the TOC. Incidental headings should render as visible local headings without entering the TOC.

6. Validate:

python -m py_compile scripts/**/*.py
xelatex -interaction=nonstopmode -halt-on-error ...
pdfinfo build/.../book.pdf
rg -n 'Overfull|Underfull|Warning|Error' build/.../*.log
sed -n '1,200p' build/.../*.toc

Completion Checklist

• Correct title and metadata match the source.
• TOC entries correspond to real body headings.
• Figures and captions are present and readable.
• No placeholder page labels remain in the booklike edition.
• No severe overfull lines or compile errors remain.
• Output PDF is synced to the requested destination when applicable.
• Tracked source/script changes are committed; original large source files remain uncommitted unless explicitly requested.