Add 12 research documents covering full PDF extraction surface
Infrastructure and parsing:
- raster-ocr-pipeline: trigger detection, preprocessing, Tesseract integration,
assisted OCR, HOCR alignment, multi-language, performance
- image-and-figure-extraction: XObjects, inline images, filter decoding,
color spaces, geometry, form XObjects, transparency, figure detection
- form-fields-and-annotations: AcroForm types, XFA, widget appearance
streams, rich text, annotation text, output schema
- pdf-encryption-and-security: R2-R6 key derivation, object-level
decryption, permission flags, RustCrypto implementation approach
- page-geometry-and-document-structure: page tree, all five page boxes,
rotation, coordinate inversion, page labels, outlines, named destinations
- optional-content-groups: OCG/OCMD visibility, usage dictionary, default
state resolution, content stream marking, multilingual layer patterns
- invisible-and-hidden-text: all 8 Tr modes, PDF/A invisible layer pattern,
white-on-white, zero-opacity, clipped text, color tracking
- malformed-pdf-repair-and-recovery: xref recovery, stream length repair,
syntax tolerance, partial extraction, structured warnings
Quality and metadata:
- xmp-and-document-metadata: /Info vs XMP, all namespaces, RDF/XML
parsing, conflict resolution, encrypted metadata, thumbnails
- embedded-files-and-portfolios: EmbeddedFile streams, Filespec,
AF relationships, Portfolio detection, ZUGFeRD/Factur-X, security
- performance-and-streaming-architecture: mmap, lazy loading, NDJSON
streaming, rayon parallelism, font caching, axum HTTP server
- benchmark-and-test-methodology: CER/WER/TEDS metrics, corpus
categories, reading order scoring, regression CI, public datasets
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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