C.8.17.2.1 Ophthalmic Photography Image Module Attribute Descriptions

C.8.17.2.1.1 Referenced Image Sequence

The Referenced Image Sequence (0008,1140) in the General Image Module (Section C.7.6.1) shall not convey stereoscopic information, which instead shall be encoded using the Stereometric Relationship IOD.

C.8.17.2.1.2 Samples per Pixel and Samples per Pixel Used

Samples per Pixel (0028,0002) shall be 1 or 3.

Cameras producing 2-color images are required to use a value of 3 for Samples per Pixel (0028,0002) and a value of 2 for Samples per Pixel Used (0028,0003). For 2-color images with a RGB Photometric Interpretation, the R and G channel shall be used and the B channel shall have all values set to zero.

Note: In the case of Photometric Interpretations typically used for compression such as YBR_FULL_422, the encoding will be as if the RGB values were transformed to YCbCr.

C.8.17.2.1.3 Photometric Interpretation

Specifies the intended interpretation of the pixel data. Enumerated Values shall be:

MONOCHROME2

RGB

YBR_FULL_422

YBR_PARTIAL_420

YBR_ICT

YBR_RCT

C.8.17.2.1.4 Image Type

The Image Type attribute (0008,0008) (General Image Module, C.7.6.1) identifies important image characteristics in a multiple valued data element. For the Ophthalmic Photography Image IOD, Image Type is specified as a Type 1 attribute and further 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;

  1. Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2; Enumerated Value is: PRIMARY

  2. Value 3 shall only be present if Value 1 is DERIVED; Defined Terms: MONTAGE.

  3. Value 4 (optionally present) shall identify the type of test performed for image acquisition. Defined terms:

COLOR - a picture take at “white” light; no filters applied

REDFREE - a picture take at “green” illumination light; or just the green channel of a color sensor

RED - a picture take at “red” illumination light; or just the red channel of a color sensor

BLUE - a picture take at “blue” illumination light; or just the blue channel of a color sensor

FA- fluorescein injected; a picture taken at fluorescein exciting illumination light; a filter passing just the emitted wavelength to sensor applied

ICG - Indocyanine green injected; a picture taken at Indocyanine green exciting illumination light; a filter passing just the emitted wavelength to sensor applied

Note: A Montage Image is constructed out of several individual images, which also can be exchanged separately. The images used to create the montage image will be included in the source image sequence if those images are also exchanged. A Montage Image is identified as Image Type DERIVED\PRIMARY\MONTAGE