getimage -- Extract an image from the CD-ROM all sky survey
The task getimage is a program for accessing the compressed image data from the CD-ROM set of the Digitized Sky Survey. Given the center coordinates and size of a field, getimage will extract the corresponding data from the CD-ROM discs, uncompress the data, and write them to an image file. The output images may be written as FITS files or GEIS (hhh/hhd) images.
The output filename is formed from a text string, up to four characters in length, that is one of the input parameters. The output filename is a concatenation of this text string and the 4-character plate-id that identifies the plate from which the image was extracted. If the output file is a FITS file, the filename extension is fits; for GEIS files, it is the usual hhh and hhd. Examples of output filenames are Test01d2.fits, or smag01d2.hhh/smag01d2.hhd.
The GetImage software, that comes with the CD-ROM set, must be installed on your system independently of STSDAS. It can be executed in a stand-alone mode or from within the GASP package. The task getimage executes the GetImage software as a foreign task. If you attempt to execute the getimage task and you get an error of the form "getimage: Command not found," you must make certain that the GetImage software directory is in your login path. This will enable you to execute the GetImage software by entering getimage both in stand-alone mode or from within the GASP package of STSDAS.
The mount point of your local CD-ROM reader is one of the hidden parameters of this task. If you are running under UNIX, it must be properly set before executing this task. This parameter is ignored on VMS systems.
If you plan to run the GetImage software both in a stand-alone mode as well as from within the GASP package, you should keep in mind that some of the default values for the parameters of this task are not the same as the default execution options in the stand-alone mode.
1. Extract an image from the CD-ROM all sky survey
ga> getimage "SMAG" 0:51:5.0 -73:0:15.5 equinox=J2000