fixregion -- image region file converter from the image file it was extracted, to another instrument/detector system.
regfile 1 imgfile convfile[extnum] out_regfile
regfile 2 cdelt1 cdelt2 crpix1 crpix2 crval1 crval2 crota2 ctype1 convfile[extnum] out_regfile
This task converts a region from one system (system1) of observation to another (system2) based on the reference coordinates in the FITS files of the two systems of observations. The region file is produced by SAOimage and save the image file before exiting SAOimage. This image file is then input file for the converter. The convfile is the file containing the coordinate information (CDELT*, CRPIX*, CRVAL*, CROTA*, CTYPE*) to be converted to. NOTE: BE SURE WHILE RUNNING FIXREGION, THIS FILE SHOULD BE SUPPLIED WITH APPROPRIATE EXTENSION NUMBER (e.g. filename[extnum]). The usefulness of the region converter is that selected region from one image file can be used in another system, provided the reference coordinates in both systems are known. The maximum no. of regions to be selected in the region file is 40. This task is introduced to mask nearby sources. The acceptable shapes for the regions are the following:
circle box ellipse point annulus
The following reference keywords and their values are read from the FITS files.
They are passed to the ftwldp.f and xy2sky.f routines which compute the new coordinates.
CRPIX1 = X axis reference pixel CRPIX2 = Y axis reference pixel CRVAL1 = Sky coord of X ref pixel (degrees) CRVAL2 = Sky coord of Y ref pixel (degrees) CDELT1 = X axis increment (degrees) CDELT2 = Y axis increment (degrees) CROTA2 = Rotation angle CTYPE1 = RA projection type
If the input system1 file (imgfile) is not present then it asks for these relevant keywords from the user.
None known. The convfile should be used with its extension number where the coordinate information to be found.
help on fregcon, ftwldp.f, xy2sky.f
For example, if the region filename is REG.IN, image filename is REG.IMG, the convfile name is CONV.FITS with primary extension for coordinate information, the outfile name REG.OUT, then the command line
fixregion reg.in 1 reg.img convfile=conv.fits out_regfile=reg.out
LOG OF SIGNIFICANT CHANGES:v1.1.0 (July, 1996) provision to handle any type of convfile v1.0.0 (May, 1996) created PRIMARY AUTHOR: Banashree Mitra Seifert HEASARC, NASA/GSFC http://heasarc.gsfc.nasa.gov/cgi-bin/ftoolshelp