DICOM PS3.18 2021c - Web Services

8.7.3.3 Bulkdata Media Types (Current)
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#### 8.7.3.3 Bulkdata Media Types

Bulkdata representations are only supported by RESTful services. There are two categories of Bulkdata: uncompressed and compressed.

The Selected Media Type will be the default media type for the Resource Category when the origin server supports none of the Acceptable Media Types, as described in Section 8.7.8, unless the origin server has only access to the pixel data in lossy compressed form or the pixel data in a lossless compressed form that is of such length that it cannot be encoded in the Explicit VR Little Endian Transfer Syntax.

The origin server may support additional Transfer Syntaxes.

If no media type Transfer Syntax parameter is specified, then the Explicit VR Little Endian Transfer Syntax "1.2.840.10008.1.2.1" shall be used, unless the origin server has only access to the pixel data in lossy compressed form or the pixel data in a lossless compressed form that is of such length that it cannot be encoded in the Explicit VR Little Endian Transfer Syntax.

### Note

The tables in this section have no entries for the URI service, since they do not support separate retrieval of Bulkdata.

Depending on the Selected Media Type, the pixel data of a resource in the Single Frame Image Resource Category is encoded in:

- one compressed Bulkdata representation, or

- one uncompressed Bulkdata representation.

Depending on the Selected Media Type, the pixel data of a resource in the Multi-Frame Image Resource Category is encoded in:

- multiple Single Frame Image compressed Bulkdata representations: one for each frame, or

- one Multi-Frame Image uncompressed Bulkdata representation.

Depending on the Selected Media Type, the pixel data of a resource in the Video Resource Category is encoded in:

- one Video compressed Bulkdata representation, or

- one Video uncompressed Bulkdata representation.

##### 8.7.3.3.1 Uncompressed Bulkdata Media Types

Table 8.7.3-4 specifies the default media type and Transfer Syntax UIDs, by Resource Category (see Table 8.7.2-1) that can be used with uncompressed Bulkdata for the RESTful services. Uncompressed Bulkdata is encoded as a stream of uncompressed bytes (octets) in Little Endian byte order.

### Note

This is the same encoding defined in PS3.19 for the returned value of the getData() call for uncompressed Bulkdata.

Table 8.7.3-4. Transfer Syntax UIDs for Uncompressed Data in Bulkdata

Category | Media Type | Transfer Syntax UID | Transfer Syntax Name | RESTful
--- | --- | --- | --- | ---
Single Frame Image | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Multi-Frame Image | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Video | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Text | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Other | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D

### Note

Even though the Transfer Syntax is Explicit VR Little Endian, the Value Representation is not actually encoded at the beginning of the octet-stream. The Value Representation is contained in the Metadata that references the Bulkdata.

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8.7.3.2 Metadata Media Types | Home | 8.7.3.3.2 Compressed Bulkdata Media Types

DICOM PS3.18 2021c - Web Services