FSAOI (Jun92)                 ftools.fimage                FSAOI (Jun92)



NAME
    fsaoi --  Translate an SAOImage region file to  an  input  file  for
    FSELECT
    
    
USAGE
    fsaoi infile outfile
    
    
DESCRIPTION
    This  task  reads  a region file created by SAOImage, and translates
    it into the correct format for input to FSELECT.   Since  SAOImage's
    output  is  in  pixel coordinates rather than the coordinates of the
    image file, FSAOI will translate  the  values  using  the  keywords:
    CRVALn,  CRPIXn  and  CDELTn,  as  well  as the names of the columns
    corresponding to the axes of  the  image  (XCOLNAME  and  YCOLNAME).
    The  task  F2DHISTO  writes  the correct values of these keywords in
    the primary array header.  If keywords are missing from the  primary
    header  of  the  input  imagefile, they can be supplied to this task
    via hidden parameters.  The default hidden parameters correspond  to
    no  transformation.   If the keywords are present in the image file,
    the hidden parameter values are ignored.
    
    
PARAMETERS
    
    infile [filename]
        The name of the ASCII SAOImage region file to be translated.
    
    outfile [filename] 
        The name of the output FSELECT file.
    
    imgfile [filename]
        The name of the file containing the original  image.   This  the
        header  of  this  file  contains  all  the information needed to
        translate SAOImage's pixel coordinate  to  the  original  file's
        coordinates.   If  this  file  is  not  available,  or  does not
        contain the correct keywords, the user will have to specify  the
        values needed through hidden parameters.
    
    (xcolname="X") [string]
        The  name  of  the  column  corresponding  to  the X axis of the
        original image.
    
    (ycolname = "Y") [string]
        The name of the column  corresponding  to  the  Y  axis  of  the
        original image.
    
    (crval1 = 1.) [real]
        Coordinate value of X reference pixel
    
    (crval2 = 1.) [real]
        Coordinate value of Y reference pixel
    
    (crpix1 = 1) [integer]
        X axis reference pixel number
    
    (crpix2 = 1) [integer]
        Y axis reference pixel number
    
    (cdelt1 = 1.) [real]
        X axis coordinate increment
    
    (cdelt2 = 1.) [real]
        Y axis coordinate increment
        
        
EXAMPLES
    1.   Read  the  file  saoimage.reg and write the appropriate FSELECT
    expression to the file fselect.in
    
         ft> fsaoi saoimage.reg fselect.in
    
    
BUGS
    FSAOI will not produce correct results  for  images  with  different
    scale  factors  in the X and Y direction (CDELT1 .ne. CDELT2) if the
    selected region includes a rotation angle.
    
    
SEE ALSO
    fselect, f2dhisto