PDF Parsing

Benched.ai Editorial Team

PDF parsing extracts structured text, images, and metadata from Portable Document Format files for downstream AI tasks.

Parsing Approaches

Approach	Library	Strength
Text extraction	pdfminer.six	Accurate text
Layout + table	PyMuPDF + HiDE	Preserve layout
OCR fallback	Tesseract	Scanned docs

Common Pitfalls

Issue	Symptom	Fix
Ligatures	Missing 'fi'	Text re-map table
Column merge	Mixed lines	Use XY positions
Annotation skip	Lost comments	Parse /Annots

Current Trends (2025)

LayoutLMv4 jointly learns text + bounding boxes for better tokenization.
GPU-accelerated PDF renderers reach 300 pages/s.
AI-based structure recovery splits paragraphs, tables, figures.

Implementation Tips

Deduplicate header/footer lines via regex.
Store page number with each token for citation.
Fallback to OCR when charmap extraction <50 % coverage.