Multilingual-pdf2text

Until extractors treat Devanagari, Arabic, and Latin as equal citizens rather than Latin + exceptions, the Babel pipeline will remain incomplete. The final step is not better code. It is recognizing that a page of text is not a rectangle to be scanned, but a cultural artifact to be translated—in the deepest sense of the word. : ~1,850 Total with headings : ~2,100

Thus, the task of is not mere conversion. It is inverse rendering —deducing logical structure (words, lines, paragraphs, reading order) from graphical instructions. Adding multiple languages (Latin, Cyrillic, CJK, Arabic, Devanagari) does not simply scale the problem; it changes its nature. Each writing system brings its own topological logic: right-to-left ligatures, context-dependent glyphs, vertical flow, zero-width joiners, and diacritic stacking. A universal extractor must therefore function as a polyglot archaeologist, reconstructing a lost semantic layer from visual fragments. 2. The Technical Stack: From pdftotext to Transformers A mature multilingual pipeline is not a single tool but a stratified architecture. multilingual-pdf2text

# Conceptual pipeline (pseudo-code) class MultilingualPDFExtractor: def extract(self, path): # Stage 0: Render to image + text layer images = pdf2images(path, dpi=150) raw_textruns = pdfminer_extract(path) # Stage 1: Glyph-to-character (HarfBuzz shaping) char_sequence = harfbuzz_shape(raw_textruns, font=extract_fonts(path)) # Stage 2: Reading order (detect columns / vertical text) blocks = cluster_by_position(char_sequence) ordered = resolve_reading_order(blocks) # ML or heuristic # Stage 3: Language ID per block (CLD3) for block in ordered: lang, confidence = detect_language(block.text) if confidence < 0.7: # Fallback to OCR for this block block = ocr_region(images, block.bbox) block.lang = lang # Stage 4: BiDi reordering if RTL if script_is_rtl(lang): block.text = bidi_reshape(block.text) # Stage 5: Normalization (NFKC for compatibility) return unicodedata.normalize('NFKC', ' '.join(block.text for block in ordered)) Until extractors treat Devanagari, Arabic, and Latin as

(heuristics + ML). PDFs lack a DOM tree. Text blocks must be clustered by Y-coordinates (lines), then X-coordinates (words), then sorted. For Latin, a simple top-to-bottom, left-to-right rule works 80% of the time. But for Mongolian (vertical), traditional Japanese (top-to-bottom, right-to-left columns), or mixed scripts (Arabic text with Latin numbers), static heuristics fail. Modern systems (e.g., Adobe’s Extract API, Google’s DocAI) use layout-aware transformers (LayoutLM, Donut) trained on millions of document pages to infer logical spans. : ~1,850 Total with headings : ~2,100 Thus,