Little has been said so far about the image data format that PHOTOM programs will work with. The native format that these use is the Starlink NDF (see SUN/33). Files that contain an NDF are identified by the extension `.sdf' and are accessed by PHOTOM programs when you just give the filename without an extension. So for instance if you have a file `image.sdf' that contains an NDF then you just supply the response `image' when prompted for an input image.
In addition to the NDF PHOTOM programs can also be made to use images in other formats, such as disk FITS, old-style FIGARO and IRAF, using the `on-the-fly' conversion abilities of the NDF library. To make this work for you, you need to setup the CONVERT (SUN/55) package and then pass images to PHOTOM programs together with their file extensions. So if you wanted to work on the IRAF image `pix.imh' you'd use a command sequence like:
In this case the file extension ``tells'' PHOTOM and the KAPPA program DISPLAY that they have an IRAF image. You should look at the CONVERT document (SUN/55) to see the list of formats that can be processed.% convert % kappa % xmake xwindows -overlay -ovcolour green % display in=pix.imh device=xw % photom in=pix.imh device=xov ... enter interactive command loop ...
PHOTOM --- A Photometry Package