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Crate djvu_rs

Crate djvu_rs 

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Pure-Rust DjVu decoder written from the DjVu v3 public specification.

This crate implements the full DjVu v3 document format in safe Rust, including IFF container parsing, JB2 bilevel decoding, IW44 wavelet decoding, BZZ decompression, text layer extraction, and annotation parsing. All algorithms are written from the public DjVu spec with no GPL code.

§Key public types

§Quick start

use djvu_rs::Document;

let doc = Document::open("file.djvu").unwrap();
println!("{} pages", doc.page_count());

let page = doc.page(0).unwrap();
println!("{}x{} @ {} dpi", page.width(), page.height(), page.dpi());

let pixmap = page.render().unwrap();
// pixmap.data: RGBA bytes

§IFF parser

use djvu_rs::iff::parse_form;

let data = std::fs::read("file.djvu").unwrap();
let form = parse_form(&data).unwrap();
println!("form type: {:?}", std::str::from_utf8(&form.form_type));

Re-exports§

pub use bzz as bzz_new;
pub use iw44 as iw44_new;
pub use error::DjVuError;
pub use djvu_document::ComponentDirectoryEntry;
pub use djvu_document::ComponentId;
pub use djvu_document::ComponentKind;
pub use djvu_document::ComponentResolveError;
pub use djvu_document::ComponentResolver;
pub use djvu_document::DjVuBookmark;
pub use djvu_document::DjVuDocument;
pub use djvu_document::DjVuPage;
pub use djvu_document::DocError;
pub use editor::DocumentEditor;
pub use editor::EDIT_SCHEMA_VERSION;
pub use editor::EditError;
pub use editor::EditOperation;
pub use editor::EditOperationKind;
pub use editor::EditPlan;
pub use editor::EditRequest;
pub use editor::EditTarget;
pub use editor::PlannedEdit;
pub use component_graph::ComponentGraph;
pub use component_graph::ComponentNode;
pub use component_graph::ComponentNodeKind;
pub use component_graph::GraphError;
pub use semantic_diff::PlaneDiff;
pub use semantic_diff::PlaneStatus;
pub use semantic_diff::SemanticDiff;
pub use semantic_diff::semantic_diff;
pub use resource_limits::DEFAULT_MAX_RENDER_PIXELS;
pub use resource_limits::ParseOptions;
pub use resource_limits::ResourceLimitAxis;
pub use resource_limits::ResourceLimitExceeded;
pub use resource_limits::ResourceLimits;
pub use validate::Finding;
pub use validate::Layer as ValidationLayer;
pub use validate::ResourceEstimate;
pub use validate::Severity;
pub use validate::ValidateOptions;
pub use validate::ValidationReport;
pub use validate::ValidationSummary;
pub use export_control::ExportObserver;
pub use export_control::NoOpObserver;
pub use text::TextLayer;
pub use text::TextZone;
pub use text::TextZoneKind;

Modules§

annotation
Annotation parser for DjVu ANTz/ANTa chunks — phase 4.
bzz
BZZ decompressor — clean-room implementation.
bzz_encode
BZZ compressor — encoding counterpart to bzz. Backwards-compatible BZZ compressor module.
cbz
DjVu to CBZ (comic book archive) exporter.
chunk_encode
Chunk-encoder seam — one (id, payload) interface (chunk_encode::ChunkEncoder) over the per-chunk encoders, with a single chunk_encode::EncodeError discipline (no panic, no silent truncation). Chunk-encoder seam — one (id, payload) interface over the per-chunk encoders.
component_graph
Validated dependency graph for bundled FORM:DJVM components. Validated dependency graph for bundled FORM:DJVM documents.
djvm
DJVM document merge and split operations. DJVM document merge and split operations.
djvu_async
Async render surface for DjVuPage — phase 5 extension.
djvu_document
New document model — phase 3.
djvu_encode
High-level page encoder — composes the codec primitives into a complete FORM:DJVU page.
djvu_mut
In-place document mutation — byte-preserving rewrite primitive (PR1 of #222).
djvu_render
Rendering pipeline for DjVuPage — phase 5.
djvu_tile
Tile-first rendering API for viewer engines (#691).
editor
Versioned, typed document editing operations with validation and atomic output handoff. Typed, validated document editing operations.
epub
DjVu to EPUB 3 exporter.
error
Typed error hierarchy for the new implementation (phase 1).
export_async
Async adapters for the synchronous PDF and DJVM streaming writers. Async adapters for the synchronous streaming export writers.
export_control
Shared progress reporting and cooperative cancellation for export writers. Shared progress reporting and cooperative cancellation for export writers.
ffi
C FFI bindings for foreign language integration.
fgbz_encode
FGbz foreground-palette encoder — produces FGbz chunk payloads.
iff
IFF container parser (phase 1, written from spec). Backwards-compatible IFF module.
image_compat
image::ImageDecoder integration — allows DjVu pages to be used as first-class image sources in the image crate ecosystem.
ingest
Encoder ingest policy — alpha, bit-depth down-conversion, and related knobs (#694). See docs/encoder-ingestion.md for the supported input matrix. Encoder input normalization policy (#694).
iw44
IW44 wavelet image decoder — clean-room implementation (phase 2c).
iw44_encode
IW44 wavelet encoder — produces BG44/FG44/TH44 chunk payloads.
jb2
JB2 bilevel image decoder — clean-room implementation.
jb2_encode
JB2 bilevel image encoder — produces Sjbz chunk payloads.
metadata
Document metadata parser for METa/METz chunks — phase 4 extension.
navm_encode
NAVM bookmark encoder — serializes djvu_document::DjVuBookmark trees to BZZ-compressed binary. NAVM bookmark encoder.
ocr
Pluggable OCR backend trait and error types.
ocr_neural
Experimental neural OCR placeholder (requires ocr-neural feature). Experimental neural OCR placeholder (requires ocr-neural feature).
ocr_onnx
Experimental ONNX OCR helper via tract (requires ocr-onnx feature). Experimental ONNX OCR via tract (requires ocr-onnx feature).
ocr_tesseract
Tesseract OCR backend (requires ocr-tesseract feature). Tesseract OCR backend (requires ocr-tesseract feature).
optimizer
High-level document optimization planning and safe structural cleanup. Document-level optimization planning, safe lossless cleanup and quality-aware archival re-encoding.
pdf
DjVu to PDF converter — phase 6.
png_io
PNG file → Pixmap decoder.
quality
Perceptual image-quality metrics (PSNR, SSIM) for render experiments.
render_cache
Process-wide ceiling for the page render caches (READ_CACHE_BOUNDED).
resource_limits
Shared configurable resource limits for parse, render, and validate. Configurable resource limits shared by validation, parse, and render entry points.
segment
Photometric foreground/background segmentation — splits an RGBA page into a bilevel ink mask and a sub-sampled background pixmap.
semantic_diff
Semantic comparison of two documents (#696): page properties, text, annotations, metadata, bookmarks, and the component graph. Semantic comparison of two DjVu documents (#696).
smmr
Smmr chunk codec — ITU-T G4 (MMR) bilevel image compression.
text
DjVu text layer — data model and parser.
text_encode
TXTa/TXTz text layer encoder — writes text::TextLayer back to DjVu binary format. TXTa/TXTz text layer encoder.
text_serialize
hOCR and ALTO XML serialization for the text layer.
thumbnail
TH44 thumbnail generation for multi-page bundles.
tiff_export
DjVu to TIFF exporter — phase 4 format extension.
validate
Layered, non-rendering DjVu document validation.
wasm
WebAssembly bindings for djvu-rs.

Structs§

Bitmap
A 1-bit-per-pixel packed bitmap image.
Document
A parsed DjVu document. Owns the parsed structure.
GrayPixmap
An 8-bit grayscale image, 1 byte per pixel.
Page
A page within a DjVu document.
PageInfo
Metadata from the INFO chunk of a DjVu page.
Pixmap
An RGBA pixel image, 4 bytes per pixel.

Enums§

BzzError
BZZ compression decoding errors.
Error
Original error type used by the legacy implementation.
IffError
Errors that can occur while parsing the IFF container.
Iw44Error
IW44 wavelet image decoding errors.
Jb2Error
JB2 bitonal image decoding errors.
PixmapError
Why Pixmap::try_new refused to allocate.
Rotation
Page rotation encoded in INFO flags bits 0–1.
ThumbnailStrategy
Policy for Document::thumbnails_with_strategy: how to source each page’s thumbnail.

Type Aliases§

Bookmark