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
CATEGORY
mar00 ftools.mkhratio