Table C.11.14-1 contains Attributes that describe the identification of two sets of grayscale images and the grayscale transformations to be applied to them, for the purpose of blending.
Table C.11.14-1PRESENTATION STATE BLENDING MODULE ATTRIBUTES
|Attribute Name||Tag||Type||Attribute Description|
|Blending Sequence||(0070,0402)||1||A Sequence of Items, one identifying and describing transformations upon a set of underlying grayscale images, and the other identifying and describing transformations upon a set of superimposed grayscale images. Two Items shall be included in this sequence See C.184.108.40.206.|
|>Blending Position||(0070,0405)||1||Whether or not the contents of the Item represent the superimposed or underlying image set. Enumerated Values: SUPERIMPOSED UNDERLYING|
|>Study Instance UID||(0020,000D)||1||Unique identifier for the Study that contains the images, which may differ from the Study in which the presentation state is contained.|
|>Include Presentation State Relationship Macro Table C.11.11-1b|
|>Include Modality LUT Macro Table C.11-1b 1b if a Modality LUT is to be applied to referenced image(s)|
|>Softcopy VOI LUT Sequence||(0028,3110)||1C||Defines a sequence of VOI LUTs or Window Centers and Widths and to which images and frames they apply. No more than one VOI LUT Sequence containing a single Item or one pair of Window Center/Width values shall be specified for each image or frame. One or more Items shall be included in this sequence. Required if a VOI LUT is to be applied to referenced image(s).|
|>>Referenced Image Sequence||(0008,1140)||1C||Sequence of Items identifying images that are defined in the enclosing Item of the Blending Sequence (0070,0402), to which this VOI LUT or Window Center and Width applies. One or more Items shall be included in this sequence. Required if the VOI LUT transformation in this Item does not apply to all the images and frames in the enclosing Item of the Blending Sequence (0070,0402).|
|>>>Include Image SOP Instance Reference Macro Table 10-3|
|>>Include VOI LUT Macro Table C.11-2b|
|Relative Opacity||(0070,0403)||1||A value from 0.0 to 1.0 indicating the relative opacity of the pixels of the superimposed image, where 1.0 means that pixels of the superimposed image completely replace the pixels of the underlying image, and 0.0 means that the pixels of the underlying image completely replace the pixels of the superimposed image. See PS 3.4 for a detailed description of the blending operation.|
|Referenced Spatial Registration Sequence||(0070,0404)||3||A reference to Spatial Registration Instances that may be used to register the underlying and superimposed images. One or more Items are permitted in this sequence. Note: A Spatial Registration Instance may identify registration between frames of reference, or between explicitly identified images. In the latter case, the list of images referenced by the Presentation State, not the list of images referenced by the Spatial Registration Instance, are to be blended.|
|>Include ‘Hierarchical SOP Instance Reference Macro’ Table C.17-3|
The Blending Sequence (0070,0402) Attribute is used to identify two sets of images, one to be superimposed upon the other.
The sets of images and any subset of the frames therein in the case of multi-frame images are identified by Study, Series, SOP Instance and Frame Number. In the case of a Segmentation image, the subset of segments is identified by the attribute Referenced Segment Number (0062,000B) in the Referenced Image Sequence (0008,1140) invoked in the Presentation State Relationship Macro.
This module specifies no explicit relationship (such as pairing or ordering) between the sets of images and frames defined in the first item for the underlying images, and the second item for the superimposed images. This module does not define how the images are spatially related, and what re-sampling, if any, needs to be performed before the images are blended for rendering.
Notes: 1. The images in the two sets may share the same Frame of Reference, in which case the rendering application can spatially relate the two sets of images based on their Image Position (Patient) (0020,0032) and Image Orientation (Patient) (0020,0037) Attributes.
Alternatively, a Spatial Registration SOP Instance may exist that relates either two different Frames of Reference, or two sets of images identified by UID and frame.
Whilst the two sets of images may already be spatially co-registered and oriented in the same plane, or even be sampled at the same in-plane and between-plane resolution, this will frequently not be the case.
See PS 3.4 for behavioral requirements that apply to Storage SOP Classes using this Module.
2. The underlying image for a superimposed Segmentation image need not be the source image for the segmentation.