MKHRATIO (mar00)             ftools.mkhratio            MKHRATIO (mar00)



NAME
    mkhratio -- generates hardness-ratio image
    
    
USAGE
    mkhratio afile bfile outfile sclmode sclfact [nbins] amin bmin
    
    
DESCRIPTION
    
       This  task  generates  a  hardness  ratio  image from two images.
    Image A    is the soft band, and Image B  is  the  hard  band.   The
    output  image     is  basically  composed of the values (B - A)/(B +
    A). The result    corresponds to the range -1 to +1,  which  can  be
    scaled  by  several     methods,  such as a power of e, linearly, or
    binning into a linear    histogram.  It is also possible  to  set  a
    cut value for each image    below which the pixel will be ignored.
    
    
    
PARAMETERS
    
    afile (Image A file) [filename]
        Location of file to consider as Image A, the soft band image.
    
    bfile (Image B file) [filename]
        Location  of  file  to consider as Image B, the hard band image.
        Must be same size as Image A.
    
    outfile [filename]
        Location of the output image file. The header from  Image  A  is
        copied into the output file.
    
    sclmode (scaling mode: EXP, LINEAR, or HIST) [string]
        Mode of scaling.
        
           EXP:              sclfact*e^((B-A)/(B+A))             LINEAR:         
        sclfact*((B-A)/(B+A))     HIST:    The  values  (B-A)/(B+A)  are 
        evenly  partitioned  into  an            'nbins' number of bins.
        The resulting image contains            the  bin  number,  which
        ranges from 1 to nbins.
        
        If B+A = 0, the value in the output image is zero.
    
    sclfact [real]
        The scaling factor used to multiply the hardness ratio.
    
    nbins [integer]
        The  number  of  bins  used  to  partition the range of hardness
        ratios.  Only applicable when sclmode=HIST.
    
    amin [integer]
        The minimum value of a pixel to use in Image  A.   Pixels  below
        this value are assigned zero in the output image.
    
    bmin [integer]
        The  minimum  value  of a pixel to use in Image B.  Pixels below
        this value are assigned zero in the output image.
    
    (tchat = 10) [integer]
        Set terminal chattiness.
    
    (lchat = 0) [integer]
        Set log file and chattiness in the log file: = 0  the  log  file
        is not written.
        
        (clobber = no) [boolean]
            If true,  an  existing  file  with  the  same  name  as  the
            requested output file will be overwritten.
        
        
EXAMPLES
     Generate a hardness ratio image with a linear scaling such that
     the resulting image contains values from 20 to 40, and pixels with
     less than 2 counts in each original image zeroed out in the final
     image.
    
       > mkhratio soft.img hard.img hr.img sclmode=linear sclfact=20 amin=2 bin=2
    
    
SEE ALSO
    mkcolor