(registered 2016-07-01, last updated 2016-07-01) Name: David Clunie Email: dclunie&dclunie.com Media type name: image Media subtype name: dicom-rle Required parameters: N/A Optional parameters: N/A Encoding considerations: binary N/A Security considerations: The DICOM RLE encoded data contains only image pixels without metadata. As such, it does not in itself create security risks beyond the information disclosed on viewing the image. There is no means to induce any particular behavior by the recipient application. The media type does not provide any privacy or integrity services, so, if needed these may be provided externally, e.g., through the use of TLS or Cryptographic Message Syntax (CMS). This media type employs compression, so users are warned that decompression may lead to significant increase in the size of the data. Theoretically, a maliciously crafted object could expand to many times its original size. Interoperability considerations: Though the DICOM RLE encoding is historically derived from the Apple and TIFF PackBits encoding [https://en.wikipedia.org/wiki/PackBits], it is not expected that non-DICOM-aware applications will be able to interoperate. The primary utility of a content type for this encoding is as a means of separately conveying the bulk data that is the pixel data from the meta data that is present in the other parts of a DICOM object, and identifying that bulk data with a standard content type. Published specification: The DICOM RLE encoding is defined in DICOM PS3.5 Data Structures and Encoding - Annex G Encapsulated RLE Compressed Images [http://dicom.nema.org/medical/dicom/current/output/chtml/part05/chapter_G.html] Applications which use this media: The DICOM RLE encoding is primarily used in the medical field, particularly to encode grayscale or color Ultrasound images. In this role it may be used for single or multi-frame images, but does not take advantage of any inter-frame correlation (i.e., is a still image compression mechanism). When pixel data of a single frame is extracted from its DICOM encapsulated representation, it is highly desirable that such extracted pixel data be made available using web services and identified with a standard media type. Fragment identifier considerations: DICOM RLE encodes single frame rasterized pixel data that is encoded in a compressed bit stream that is not fragmented and is decoded starting at the beginning of the bit stream. As such, no media type specific fragment identifier or fragment semantics are defined. In particularly no mechanism to selectively locate positions or sub-regions within an image is defined. Restrictions on usage: None. Provisional registration? (standards tree only): image/dicom+rle Additional information: 1. Deprecated alias names for this type: image/x.dicom+rle 2. Magic number(s): N/A 3. File extension(s): drle 4. Macintosh file type code: 'drle' 5. Object Identifiers: N/A General Comments: Person to contact for further information: 1. Name: David Clunie 2. Email: dclunie&dclunie.com Intended usage: Common Common Author/Change controller: DICOM Standards Committee dicom&medicalimaging.org