Some image data consists of a group of related planes, such as the red, green, and blue planes of a color image or the left and right views of a stereo pair, etc. For ease of transport and handling, it is posible to store multiple planes in one file. The multi_plane_flag field in the plane file header is used to indicate when multiple planes are stored in a given file. If this field is equal to zero, then only one plane is stored in the file. If this field is not equal to zero, then another plane file header record, association list record, plane size record, and plane data record follow after the current plane data record. The last plane has a plane file header record with its multi_plane_flag field set to zero. The value stored in this field is the number of remaining planes in the file. That is, if the file contains three planes, the value in the first plane's multi_plane_flag header field is 2, the value in the second planes' multi_plane_flag header field is 1, and the value in the third (and last) multi_plane_flag header field is 0.