imppm is a link to the
utility which finds all of the
stars in a FITS or IRAF image and lists their sky and image positions.
World coordinate system (WCS) information
must be present in the image header to describe, in a standard way, the
relationship between sky coordinates and image pixels.
This information is used by the program to find the region in the sky to
search and to transform right ascension and declination sky coordinate pairs
to image coordinate (X,Y) pairs. Output is sent to a file called
filename.gsc and to standard output if the -v flag is set.
The minimum command line is
Find PPM Catalog Stars in Image Region
imppm FITS or IRAF filename
The same effect can be obtained by running
imcat -c ppm FITS or IRAF filename