Search Engine Adds PDF Indexing: Conquering the Challenges of Text Extraction

The search engine recently gained the ability to index PDFs, a feat more complex than it seems. PDFs aren't text-based; they're graphical, representing text as glyph coordinates that may be rotated, overlapping, or disordered. This article details improvements to PDFBox's PDFTextStripper class. By statistically analyzing font sizes and line spacing, it more effectively identifies semantic information like headings and paragraphs. This enhances the accuracy and suitability of PDF text extraction, enabling effective indexing of PDF content.