Table C.8.20-5 defines the Attributes of the Height Map Segmentation Image Module.
Table C.8.20-5. Height Map Segmentation Image Module Attributes
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Image identification characteristics. Value 1 shall be DERIVED. Value 2 shall be PRIMARY. No other values shall be present. |
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Include Table 10-12 “Content Identification Macro Attributes” |
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Number of rows in the image. Value shall be identical to the number of frames referenced in the Derivation Image. See Section C.8.20.5.2. |
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Number of columns in the image. Value shall be identical to value of Columns (0028,0011) in the Derivation Image. See Section C.8.20.5.1. |
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The type of encoding used to indicate the presence of the segmented property at a location in the derivation image. See Section C.8.20.5.1. |
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>Include Table C.8.20-4 “Segment Description Macro Attributes” |
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Name of algorithm used to generate the segment. Required if Segment Algorithm Type (0062,0008) is not MANUAL. |
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A description of how this segment was derived. Algorithm Name (0066,0036) within this Sequence may be identical to Segment Algorithm Name (0062,0009). Required if Segment Algorithm Type (0062,0008) is not MANUAL. |
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>>Include Table 10-19 “Algorithm Identification Macro Attributes” |
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A default single gray unsigned value in which it is recommended that this segment be rendered on a monochrome display. The units are specified in P-Values from a minimum of 0000H (black) up to a maximum of FFFFH (white). |
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A default triplet value in which it is recommended that this segment be rendered on a color display. The units are specified in PCS-Values, and the value is encoded as CIELab. See Section C.10.7.1.1. |
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Segmentation Type (0062,0001) of HEIGHTMAP specifies a segmented surface within a referenced derivation image pixel/voxel matrix volume. Each row of a Height Map Segmentation frame corresponds to a single full frame of a derivation image (see Section A.91.5.1.1) and shall have the same value for Columns (0028,0011).
The Height Map Segmentation Float Pixel Data (7FE0,0008) value specifies the location of the segmented surface in the corresponding pixel column in the referenced derivation image (see Figure C.8.20.5-1). The location is specified in units of vertical pixels from the top center of the column in the derivation image, with the floating point value providing fractional pixel resolution (see Figure C.8.20.5-2).
Note
The DICOM convention is to specify fractional pixel offsets from the top left hand corner of an image. Since the horizontal offset is specified by column correspondence between the derivation image and the Height Map Segmentation, the horizontal position is nominally the midline of the column.
A segmented surface might not span the entire frame of a derivation image, and therefore there would be columns for which there is no valid height map value. The absence of a segmented surface in a derivation image pixel column is specified by a "padding value" in the height map, i.e., a height map value in the range specified by Float Pixel Padding Value (0028,0122) and Float Pixel Padding Range Limit (0028,0124) in the Floating Point Image Pixel Module (see Section C.7.6.24). The padding value range shall not overlap the range of zero to the number of rows of the derivation image.