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ACCESSING HEADER INFORMATION

Most astronomical images have collections of numeric, character or logical values associated with them. Typically these consist of important calibration values, but they are also often used to describe the history or status of the data. Collections of such data, which are not actually part of the image array, are known as ``header'' information (this name derives from the fact that FITS1 stores these values at the beginning - head - of a file). IMG refers to a single piece of such information as a ``header item'' and a separate set of subroutines exists to read, write, copy and make enquiries about them.





next up previous 231
Next: Reading header items
Up: IMG Simple Image Data Access
Previous: Modifying a copy of an image

IMG Simple Image Data Access
Starlink User Note 160
P.W. Draper
R.F. Warren-Smith
3 March 2003
E-mail:P.W.Draper@durham.ac.uk

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