iterstat: Compute image statistics using iterative rejection
Package: xdimsum
Usage
iterstat inlist
Parameters
- inlist
- The list of images for which the statistics are to be computed.
- statsec = ""
- The input image section used to compute the statistics. Statsec is ignored if the input image name includes a section specification.
- lower = INDEF
- The initial lower bad data limit.
- upper = INDEF
- The initial upper bad data limit.
- nsigrej = 3.0
- The k-sigma bad data rejection criterion.
- maxiter = 20
- The maximum number of bad data rejection cycles.
- show = yes
- Print the results for the final iteration ?
- verbose = yes
- Print the results for each iteration ?
- imean
- The returned image mean estimate.
- isigma
- The returned image standard deviation estimate.
- imedian
- The returned image median estimate.
- imode
- The returned image mode estimate.
Description
The mean, standard deviation, median, and mode are estimated for each input image in inlist using iterative rejection around the mean and stored in the output parameters imean, isigma, imedian, and imode. Results for each iteration are printed on the terminal if verbose = yes, and for the final result only if show = yes.
If statsec is defined and the input image name does not include an image section then the statistics are computed inside statsec. If the input image name does include an image section statsec is ignored. Initial values for the image statistics are computed after rejected data outside the limits defined by the lower and upper parameters. New bad data limits are computed using the mean and sigma computed by the previous iteration and value of the nsigrej parameter. ITERSTAT terminates if the number of iterations >= maxiter or if no new bad pixels are detected.
ITERSTAT is a script task which makes repeated calls to IMSTATISTICS to compute the actual statistics. More information about the ITERSTAT algorithms can be found in the help page for the IMSTATISTICS task.
Examples
1. Compute the statistics for an image.
cl> iterstat demo01
2. Compute the statistics for the list of demo images but print only the final result.
cl> iterstat @demo.list verbose-
Time requirements
Bugs
See also
imstatistics