C.8.12.1 VL Image Module

Table C.8-77 specifies the Attributes that describe a VL Image produced by Endoscopy (ES), General Microscopy (GM), Automated-Stage Microscopy (SM), External-camera Photography (XC), or other VL imaging Modalities.

Table C.8-77VL IMAGE MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Image Type (0008,0008) 1 Image identification characteristics. See C.8.12.1.1.6 for specialization.
Photometric Interpretation (0028,0004) 1 Specifies the intended interpretation of the pixel data. See C.8.12.1.1.1 for specialization of this Attribute.
Bits Allocated (0028,0100) 1 Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See C.8.12.1.1.2 for specialization of this Attribute. See PS 3.5 for further explanation.
Bits Stored (0028,0101) 1 Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See C.8.12.1.1.2 for specialization of this Attribute. See PS 3.5 for further explanation.
High Bit (0028,0102) 1 Most significant bit for pixel sample data. Each sample shall have the same high bit. See C.8.12.1.1.2 for specialization of this Attribute. See PS 3.5 for further explanation.
Pixel Representation (0028,0103) 1 Data representation of the pixel samples. Each sample shall have the same pixel representation. See Section C.8.12.1.1.3 for specialization of this Attribute.
Samples per Pixel (0028,0002) 1 Number of samples (planes) per image. See C.8.12.1.1.4 for specialization of this Attribute.
Planar Configuration (0028,0006) 1C Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See C.8.12.1.1.5 for specialization of this Attribute.
Content Time (0008,0033) 1C The time the image pixel data creation started. Required if the Image is part of a series in which the images are temporally related. Note: This Attribute was formerly known as Image Time.
Lossy Image Compression (0028,2110) 2 Specifies whether an Image has undergone lossy compression. Enumerated Values: 00 = Image has NOT been subjected to lossy compression. 01 = Image has been subjected to lossy compression. See C.7.6.1.1.5
Referenced Image Sequence (0008,1140) 1C A Sequence that references other images significantly related to this image. One or more items are permitted in this sequence. Required if Image Type (0008,0008) Value 3 is present and has a value of "STEREO L" or "STEREO R". May also be present otherwise. See Section C.8.12.1.1.7.
>Include ‘Image SOP Instance Reference Macro’ Table 10-3
>Purpose of Reference Code Sequence (0040,A170) 2 Describes the purpose for which the reference is made. Zero or one item shall be included in this sequence.
>>Include Code Sequence Macro Table 8.8-1 Defined Context ID 7201
Window Center (0028,1050) 3 Window Center for display. See C.11.2.1.2 for further explanation. Meaningful only if Photometric Interpretation (0028,0004) is MONOCHROME2.
Window Width (0028,1051) 1C Window Width for display. See C.11.2.1.2 for further explanation. Required if Window Center (0028,1050) is present.
Anatomic Region Sequence (0008,2218) 1C Sequence that identifies the anatomic region of interest in this image (i.e. external anatomy, surface anatomy, or general region of the body). Only a single Item shall be included in this sequence. Required if Number of Frames (0028,0008) is present and Specimen Description Sequence (0040,0560) is absent. May be present otherwise.
>Include ‘Code Sequence Macro’ Table 8.8-1 Defined CID 4040 is defined for the Video Endoscopic IOD. For other IODs, no Context ID is defined.
>Anatomic Region Modifier Sequence (0008,2220) 3 Sequence of Items that modifies the anatomic region of interest of this image One or more Items are permitted in this Sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 2.
Include ‘Primary Anatomic Structure Macro’ Table 10.4-8 No Context ID is defined. These Type 3 Attributes are not appropriate when Specimen Description Sequence (0040,0560) is present, as it includes the Primary Anatomic Structure Macro for each specimen in the image.
Channel Description Code Sequence (0022,001A) 3 Describes the light color used for each channel to generate the image. If Photometric Interpretation (0028,0004) has one of the YBR values, the meaning is for pixel data in an equivalent RGB encoding. Note: Interpretation and representation of RGB images rely on the assumption that the red channel really contains the red wavelength range of illumination light, the blue channel the blue wavelength range, etc. Some modalities use the RGB Photometric Interpretation as a container representing 3 channels of any illumination wavelength. Shall have the same number of items as the value of Samples per Pixel (0028,0002). The channels shall be described in the order in which the channels are encoded.
>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 4206.
Pixel Spacing (0028,0030) 3 Physical distance in the imaging target (patient or specimen) between the center of each pixel, specified as a numeric pair – adjacent row spacing \ adjacent column spacing, in mm. See 10.7.1.3.

C.8.12.1.1 VL Image Module Attribute Descriptions

C.8.12.1.1.1 Photometric Interpretation

The Enumerated Values of Photometric Interpretation (0028,0004) shall be:

MONOCHROME2

RGB

YBR_FULL_422

YBR_PARTIAL_420

YBR_RCT

YBR_ICT

Note: There is no formal color space defined, hence “false” color applications that encode near-visible light images may be encoded, for example, as RGB.

C.8.12.1.1.2 Bits Allocated, Bits Stored, and High Bit

The Enumerated Value of Bits Allocated (0028,0100) shall be 8; the Enumerated Value of Bits Stored (0028,0101) shall be 8; and the Enumerated Value of High Bit (0028,0102) shall be 7.

C.8.12.1.1.3 Pixel Representation

The Enumerated Value of Pixel Representation (0028,0103) shall be 0.

C.8.12.1.1.4 Samples per Pixel

The Enumerated Values of Samples per Pixel (0028,0002) shall be as follows: If the value of Photometric Interpretation (0028,0004) is MONOCHROME2, then the Enumerated Value of Samples per Pixel (0028,0002) shall be one (1). If the value of Photometric Interpretation (0028,0004) is RGB or YBR_FULL_422 or YBR_PARTIAL_420 or YBR_RCT or YBR_ICT, then the Enumerated Value of Samples per Pixel (0028,0002) shall be three (3).

C.8.12.1.1.5 Planar Configuration

If present, the Enumerated Value of Planar Configuration (0028,0006) shall be 0. This value shall be present if Samples per Pixel (0028,0002) has a value greater than 1.

C.8.12.1.1.6 Image Type

The Image Type attribute identifies important image characteristics in a multiple valued data element. For Visible Light, Image Type is specialized as follows:

a. Value 1 shall identify the Pixel Data Characteristics in accordance with Section C.7.6.1.1.2; Enumerated Values are: ORIGINAL and DERIVED;

b. Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2; Enumerated Values are: PRIMARY and SECONDARY.

c. Value 3 may be absent, but if present shall identify the members of a stereo pair, in which case Referenced Image Sequence (0008,1140) is used to identify the other member of the pair. If present, the Enumerated Values are:

STEREO L Image is the left image (relative to the observer's left) of a stereo pair acquisition;
STEREO R Image is the right image (relative to the observer's right) of a stereo pair acquisition.

d. Other Values are implementation specific (optional).

C.8.12.1.1.7 Referenced Image Sequence

When Image Type (0008,0008) Value 3 is STEREO L or STEREO R, Referenced Image Sequence (0008,1140) shall be used to identify the corresponding SOP Instance of the Stereoscopic acquisition. In this case, either: