NIF-backed DICOM pixel data codecs for the dicom library.

Each codec implements Dicom.Codec with Rust NIFs (Rustler) over these crates:

• JPEG Baseline/Extended/Lossless: jpeg-decoder to decode, jpeg-encoder to encode (lossy Baseline only)
• JPEG 2000: openjp2, OpenJPEG ported to Rust
• JPEG-LS: charls-sys, bindings to CharLS

Usage

Add dicom_codecs to your dependencies. The application registers every codec with Dicom.Codec.Registry at startup, so a codec can be looked up by the Transfer Syntax UID of the data set:

{:ok, codec} = Dicom.Codec.Registry.lookup(transfer_syntax_uid)
{:ok, pixels} = codec.decode(compressed_frame, %{rows: 512, columns: 512, bits_allocated: 16})

Frames and metadata

Decoding returns one frame of native pixel data: samples interleaved by pixel (Planar Configuration 0), little-endian, :bits_allocated / 8 bytes per sample. Encoding expects the same layout.

:rows and :columns are required. :bits_allocated defaults to 8, :bits_stored to :bits_allocated, :samples_per_pixel to 1, :pixel_representation and :planar_configuration to 0, and :photometric_interpretation to "MONOCHROME2" (or "RGB" for three samples). A decoded frame must match the metadata in size, samples per pixel and bytes per sample.

Errors

Every NIF runs on a dirty CPU scheduler and returns {:error, {reason, message}} instead of raising, where reason is one of:

• :invalid_metadata: the metadata is malformed or describes an impossible frame
• :metadata_mismatch: the input or the decoded frame disagrees with the metadata
• :unsupported: valid input this codec does not handle
• :decode_failed / :encode_failed: the codec rejected the data
• :internal_error: a bug inside the codec (including a caught panic)

Supported Transfer Syntaxes