Add Phase 4 caption classification for detecting figure captions. Implements classify_caption() which identifies blocks as captions when: - Small font size (median < page body median) - Follows Figure block within 2 line heights - Same column as Figure Module: crates/pdftract-core/src/layout/caption.rs Acceptance criteria: - Block immediately below Figure, small font, same column → kind: Caption - Block 5 lines below Figure → NOT Caption (gap too large) - Block with body-size font below Figure → NOT Caption (font not smaller) - Block in different column from Figure → NOT Caption Tests: 9/9 passed covering all acceptance criteria plus edge cases. Closes: pdftract-xzfkt Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com> |
||
|---|---|---|
| .. | ||
| benches | ||
| build | ||
| examples | ||
| proptest-regressions/parser/lexer | ||
| src | ||
| tests | ||
| __test__.pdf | ||
| build.rs | ||
| Cargo.toml | ||
| pdftract-core.cdx.json | ||
| README.md | ||
pdftract-core
The core Rust library for PDF text extraction. This crate provides the parsing, layout analysis, font encoding recovery, and text extraction primitives used by the CLI (pdftract-cli) and Python bindings (pdftract-py).
Cargo.lock Policy
This workspace checks in Cargo.lock at the repository root. This is unconventional for library crates—the Cargo Book historically suggested that only binary crates should check in lockfiles, allowing library consumers to resolve their own dependency versions.
pdftract departs from this convention for release reproducibility:
-
SLSA Level 3 provenance requires that every milestone tag produces byte-identical artifacts across builds. Without a checked-in lockfile, two runs of
cargo buildon the same commit can resolve different transitive dependency versions, producing different binary hashes. -
Multi-output artifacts—this workspace produces Rust crates (
pdftract-core,pdftract-cli), Python wheels (pdftract-py), and Docker images. All must be built from the same dependency tree. -
Supply-chain security—the lockfile pins checksums for all transitive dependencies, enabling
cargo auditto detect yanked or compromised crates. -
Downstream consumers can still ignore the lockfile if needed. Cargo allows
cargo build --frozenwith a local lockfile override, or consumers can vendor the crate with their own dependency resolution.
The tradeoff—occasional merge conflicts when PRs update overlapping dependencies—is worth the guarantee of reproducible releases. See CONTRIBUTING.md for the lockfile-update workflow.
Modules
parser: PDF spec parsing (xref, trailer, object streams, indirect references)font: Font encoding recovery, glyph name lookup, fingerprintinglayout: Page layout analysis, region segmentation, reading orderextract: Text extraction with provenance (bounding boxes, confidence scores)ocr: Tesseract integration for raster pages
Usage
use pdftract_core::{extract_text, ExtractOptions};
let options = ExtractOptions::default();
let result = extract_text("document.pdf", &options)?;
println!("{}", result.text);