The Height Map Segmentation Information Object Definition (IOD) specifies the location of one or more layer surfaces within a 3D volume, e.g., for retinal or epithelial layers. For each coordinate of the reference plane, each layer has at most one surface point at a distance perpendicular to the reference plane. However, not all coordinates of the reference plane might have a corresponding distance specified for any particular layer.

Each frame of a Height Map Segmentation SOP Instance corresponds to a segmented layer within a referenced derivation image. Each row in a Height Map Segmentation frame corresponds to a single frame in a derivation image, and the pixel values in a row represent the height map data for a segmented layer as it intersects the derivation image frame. The Height Map Segmentation SOP Instance does not include the full set of acquisition parameters of the derivation image and frames, e.g., Plane Orientation, or Plane Position. An application rendering or processing the segmentation may need to access the referenced derivation image for such information.