Y.3 Standard Composite Instance Root Retrieve Information Model

One standard Composite Instance Root Retrieve Information Model is defined in this Annex. The Composite Instance Root Retrieve Information Model is associated with a number of SOP Classes. The following hierarchical Composite Instance Root Retrieve Information Model is defined:

– Composite Instance Root

Y.3.1 Composite Instance Root Information Model

The Composite Instance Root Information Model is based upon a two level hierarchy:

– Composite Instance

– Frame

The Composite Instance level is the top level and contains only the SOP Instance UID. The Frame level is below the Composite Instance level and contains only the Attributes that refer to a selection of the frames from a single multi-frame image object.

Y.3.2 Construction and Interpretation of Frame Range Keys

The following rules for the use of Frame Range Keys apply to both an SCU creating such keys and to an SCP interpreting them.

Y.3.2.1 Frame List Definitions

The selection of frames to be included in a new created SOP Instance made in response to a FRAME level Composite Instance Root Retrieve request shall be defined by one of the mechanisms defined in this section, and the list of frames so specified shall be referred to as the “Frame List”.

Notes: 1. Re-ordering of frames is not supported, and order of the frames in the Frame List will always be the same as in the original SOP Instance.

2. New allowable frame selection mechanisms may be defined in the future by the addition of new SOP classes

Y.3.2.1.1 Simple Frame List

Simple Frame List (0008,1161) is a multi-valued attribute containing a list of frame numbers, each specifying a frame to be included in the returned object. The first frame of the source instance shall be denoted as frame number 1.

The frame numbers in the list shall not contain any duplicates, and shall increase monotonically.

Note: Due to the use of UL for this element, a maximum of 16383 values may be specified, as only a 2 byte length is available when an explicit VR Transfer Syntax is used.

Y.3.2.1.2 Calculated Frame List

Calculated Frame List (0008,1162) is a multi-valued attribute containing a list of 3-tuples, each representing a sub-range of frames to be included in the returned object. The first frame of the source instance shall be denoted as frame number 1.For each 3-tuple: .

– The first number shall be the frame number of the first frame of the sub-range.

– The second number shall be the upper limit of the sub-range, and shall be greater than or equal to the first number.

– The third number shall be the increment between requested frames of the sub-range. This shall be greater than zero.

The difference between the first and second numbers is not required to be an exact multiple of the increment.

If the difference between the first and second numbers is an exact multiple of the increment, then the last frame of the sub-range shall be the second number.

If the first number is greater than the number of frames in the referenced SOP Instance then that sub-range shall be ignored.

The sub-ranges shall be non-overlapping such that the sequence of frame numbers determined by concatenating all the sub-ranges shall not contain any duplicates, and shall increase monotonically. A value of FFFFFFFFH or any value greater than the number of frames in the referenced SOP Instance as the second value shall denote the end of the set of frames in the referenced SOP Instance, and may only occur in the last 3-tuple.

Note: For example, if the Calculated Frame List contains 6 values, 2, 9, 3, 12, FFFFFFFFH, 5 and is applied to an Instance containing 25 frames. The resulting Frame List will contain the values 2, 5, 8, 12, 17 and 22.

Y.3.2.1.3 Time Range

Time Range (0008,1163) contains the start and end times to be included in the returned object. Times are in seconds, relative to the value of the Content Time (0008,0033) in the parent object.

The range shall include all frames between the specified times including any frames at the specified times.

The range may be expanded as a consequence of the format in which the information is stored. Where such expansion occurs, any embedded audio data shall be similarly selected. Under all circumstances, the returned Composite SOP Instance shall retain the relationship between image and audio data.

Note: For MPEG-2 this would be to the nearest surrounding Key Frames

For JPEG 2000 Part 2, this would be to nearest surrounding precinct or tile boundary

Time Range shall only be used to specify extraction from SOP instances where the times of frames can be ascertained using one or more of the following attributes:

Y.3.3 New Object Creation at the FRAME level

When a C-GET operation is performed on a source Composite Instance at the FRAME level then the SCP shall create a new Composite Instance according to the following rules:

Note: The new Composite Instance is required to be internally consistent and valid. This may require the SCP to make consistent modification of any attributes that reference frames or the relationship between them such as start time, time offsets, and modifying the Per-frame Functional Group Sequence (5200,9230).

Note: The existing General Equipment module cannot be used to hold details of the creating equipment, as it is a Series level module. The new Composite Instance is part of the same Series as the source Instance, and therefore the Series level information cannot be altered.

Note: In most cases private attributes should not be copied unless their full significance is known. See Annex ZZ in Part 17 for more guidance.