| Why PDF parsing is Hell[1]: Fixed layout and lack of semantic structure in PDFs. Non-linear text flow due to columns, sidebars, or images. Position-based text without contextual or relational markers. Absence of standard structure tags (like in HTML). Scanned or image-based PDFs requiring OCR. Preprocessing needs for scanned PDFs (noise, rotation, skew). Extracting tables from unstructured or visually complex layouts. Multi-column and fancy layouts breaking semantic text order. Background images and watermarks interfering with text extraction. Handwritten text recognition challenges. [1] https://unstract.com/blog/pdf-hell-and-practical-rag-applica... |