Trim images to the defined map area


Trim images from SCUBA-2 to a given size. The image may be trimmed using given spatial dimensions or a statistical estimator to threshold the image. In the former case, the output map is rectangular or circular; in the latter the shape is determined by the values in the image itself.

By default the method employs the map parameters in the FITS header. The map width and height may be overridden with recipe parameters. Note that if a map radius is given (when a circular output image is desired) the height and width are ignored.

The JCMT::MapArea Perl module is used to define a (rectangular) AST Region using the map parameters in the FITS header.

For the statistical estimator, the default is to trim the map excluding data where the exposure time is less than half of the median value.


Available Parameters :

The following parameters can be set via the -recpars option:
Method to use for cropping image. May be statistical, rectangle (default) or circle, each of which may be abbreviated to the first four characters.
Height of output image in arcsec.
Radius of output image in arcsec. Overrides existence of MAP_HEIGHT and MAP_WIDTH.
Width of output image in arcsec.
NDF component to use to define the threshold. May be texp to use the exposure time image, or var or err to use the variance or error components.
Statistical estimator for thresholding the image. May be MEAN, MEDIAN, MODE, MAX, MIN.
Multiplier for STATS_ESTIMATOR above. Default is 1 if not specified (or 0.5 for texp).