image data orientation

[Mark Calabretta]

On Sun 1996/03/24 02:37:55 GMT, gjarvis at synapse.net wrote
in a message to: fitsbits at fits.cv.nrao.edu

>I can not find any information on image orientation in fits standard, just how 
>memory is organised as first dimension varies fastest.
>For example a two dimensional image:
>
>1) is NAXIS1 corresponds two vertical rows of image and NAXIS2  corresponds 
>to horizontal columns of data image or is it column row?
>
>2) is data[1,1] top left, or top right, or bottom left, or bottom right of image?
>
>What about higher dimensions

There is no formal image orientation convention in FITS but one is proposed as
part of WCS (c.f. fits.cv.nrao.edu:/fits/documents/wcs/wcs.all.ps.Z), section
2.4.

WCS formalises the de facto convention which has (1,1) at bottom left, NAXIS1
horizontal, NAXIS2 vertical.

Mark Calabretta
ATNF