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3.1. Multi-dimensional vector in a binary table

A vector column in a binary table (BINTABLE) extension can be used to store a multi-dimensional image in each element (i.e. each row) of the column. In the simple case in which all the images have the same fixed size, the TDIMn keyword can be used to specify the dimensions. In the more general case, a variable length vector may be used to store different-sized images within the same column.

Because two or more columns in a binary table can contain images, the naming convention for these coordinate system keywords must encode the column number containing the image to which the keyword applies as well as the axis number within the image. The naming convention described here uses the keyword prefix to specify the axis number and the keyword suffix to specify the column number containing the image (e.g. the 2CRVL15 keyword applies to the second axis of the image in Col. 15 of the table).