DICOM PS3.17 2020a - Explanatory Information |
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GG JPIP Referenced Pixel Data Transfer
Syntax Negotiation (Informative)
The JPIP Referenced Pixel Data transfer syntaxes allow transfer of image objects with a reference to a non-DICOM network service that provides the pixel data rather than encoding the pixel data in (7FE0,0010).
The use cases for this extension to the Standard relate to an application's desire to gain access to a portion of DICOM pixel data without the need to wait for reception of all the pixel data. Examples are:
1.Stack Navigation of a large CT Study.
In this case, it is desirable to quickly scroll through this large set of data at a lower resolution and once the anatomy of interest is located the full resolution data is presented. Initially lower resolution images are requested from the server for the purpose of stack navigation. Once a specific image is identified the system requests the rest of the detail from the server.
2.Large Single Image Navigation.
In cases such as microscopy, very large images may be generated. It is undesirable to wait for the complete pixel data to be loaded when only a small portion of the specific image is of interest. Additionally, this large image may exceed the display cap- abilitiesthusresultinginadecimationoftheimagewhendisplayed.Alowerresolutionimage(i.e.,onethatmatchestheresolution of the display) is all that is required, as additional data cannot be fully rendered. Once an area of interest is determined, the ap- plication can pan and zoom to this area and request additional detail to fill the screen resolution.
3.Thumbnails.
It is desirable to generate thumbnail representations for a study. This has been accomplished through various means, many of which require the client to receive the complete pixel data from the server to generate the thumbnail image. This uses significant network bandwidth.
The thumbnails can be considered low-resolution representations of the image. The application can request a low-resolution representation of the image for use as a thumbnail.
4.Display by Dimension.
Multi-frameImagesmayencodemultipledimensions.Itisdesirableforanapplicationtoaccessonlythespecificframesofinterest in a particular dimension without the need to receive the complete pixel data. By using the multi-dimensional description, applic- ations using the JPIP protocol may request frames of the Multi-frame Image.
Theassociationnegotiationbetweentheinitiatorandacceptorcontrolswhenthismethodoftransferisused.Anacceptorcanpotentially accept both the JPIP Referenced Pixel Data transfer syntax and a non-JPIP transfer syntax on different presentation contexts. When an acceptor accepts both of these transfer syntaxes, the initiator chooses the presentation context.
Examples:
For the following cases:
•AE1 requests images from AE2
•AE1 implements a C-MOVE SCU, as well as a C-STORE SCP. AE2 implements a C-MOVE SCP, as well as a C-STORE SCU
Case 1:
•AE1 and AE2 both support both a JPIP Referenced Pixel Data Transfer Syntax and a non-JPIP Transfer Syntax
•AE1 makes a C-MOVE request to AE2
•AE2 proposes two presentation contexts to AE1, one for with a JPIP Referenced Pixel Data Transfer Syntax, and the other with a non-JPIP Transfer Syntax