dicom-parser-rs

dicom parser written in Rust

Design Goals

• Parse all standards compliant DICOM P10 files
• First class support for WebAssembly builds
• Streaming compatible API
• SAX Style callback based parsing
• Does not utilize a DICOM data dictionary
• Modular design enabling flexible re-use of the library functionality

Read about the design rationale for this library

Features

• [X] Callback based parsing
• [X] Cancel Parsing
• [X] DICOM P10 Meta Information
• [X] Explicit Little Endian Transfer Syntax
• [X] Streaming Parser
• [X] Implicit Little Endian Transfer Syntax
• [X] Explicit Big Endian Transfer Syntax
• [X] Encapsulated Pixel Data
• [X] Sequences with known lengths
• [X] Sequences with undefined lengths
• [X] UN with undefined lengths
• [ ] Deflate Transfer Syntax

Status

Actively being developed (June 20, 2020)

To Do's (before first version release)

• Add no_std configuration?
• Add example applications
  • dump to DICOM JSON format
  • dump to text (in DCMTK dcmdump format) - requires data dictionary though
• Test library with large number of images (GDCM test images, etc)
  • Would be nice to build an automated regression suite

Performance Benchmarking

Add performance benchmark to understand parser performance for various use cases and data variations. Establishing a baseline here will help avoid performance regressions due to future changes and also serve as a useful comparsion agains other parsing implementations.

• Use Cases
  • SOP Instance Identification - extract Study,Series and SOPInstanceUID Only
  • Basic Image Display - Extract minimum attributes to display image (ImagePixel Module)
  • Basic Encoding Validation - make sure the entire dataset can be parsed (ignore data though)
  • Basic Metadata - extract basic metadata like patietn demographics, study description, etc
  • Metadata ingestion - parse all metadata fields
  • Pixel Ingestion - parse all pixel data
• Data Variations
  • Transfer Syntaxes (Implicit Little Endian, Explicit Little Endian, Explicit Big Endian)
  • Pixel Data (uncompressed, compressed/encapsulated not fragmented, encapsulated fragmented)
  • Lengths (defined and undefined)
  • Sizes (large multiframe, small single frame)
  • Private Attributes (large, small)
  • Stream Parsing - full dataset, chunked, single bytes

Possible Future Functionality

• Consider helpers to convert attribute data into rust types (e.g. strings, numbers, etc)
  • Note: meta_information already has functionality to convert to utf8 strings
• Create handler that produces DICOM JSON?
• Consider adding FilterHandler that filters out handler calls for specific attributes.
• Consider adding TagCancelHandler to cancel parsing on specific tag (or tags)
• Consider making a cancelled parse resumable? Should work given that the parser is streaming capable
• Add P10StreamParser which provides a simplified interface for stream parsing by buffering data from incomplete parses
• Consider adding a Handler that aggregates mutliple data callbacks into a single buffer
• Explore ways to automate mapping from Handler to types in a struct, perhaps using macros?
  • would be nice to be able to do something like: !map(0x0020, 0x000D, &self.study_instance_uid);
  • could use this for creating the MetaInformation struct rather than a custom Handler

Refactorings

• Separate undefined length logic from known length logic
  • SequenceItemDataParser->SequenceItemDataUndefinedLengthParser
  • SequenceParser -> SequenceUndefinedLengthParser
• Refactor parse_tag_and_length() so we don't have two of them - perhaps replace with parse_attribute()?
• replace unit test dependencies on actual P10 files with synthetic data