Download Analysis Cookbook - CASA

CHAPTER 1. INTRODUCTION
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• viewer — there are useful region statistics and image cube plotting capabilities in the viewer
(§ 7).
1.5.6.1
What’s in an image?
The imhead task will print out a summary of image “header” keywords and values. This task can
also be used to retrieve and change the header values.
See § 6.2 for more.
1.5.6.2
Image statistics
The imstat task will print image statistics. There are options to restrict this to a box region,
and to specified channels and Stokes of the cube. This task will return the statistics in a Python
dictionary return variable.
See § 6.7 for more.
1.5.6.3
Moments of an Image Cube
The immoments task will compute a “moments” image of an input image cube. A number of options
are available, from the traditional true moments (zero, first, second) and variations thereof, to other
images such as median, minimum, or maximum along the moment axis.
See § 6.6 for details.
1.5.6.4
Image math
The immath task will allow you to form a new image by mathematical combinations of other images
(or parts of images). This is a powerful, but tricky, task to use.
See § 6.5 for more.
1.5.6.5
Regridding an Image
It is occasionally necessary to regrid an image onto a new coordinate system. The imregrid task
can be used to regrid an input image onto the coordinate system of an existing template image,
creating a new output image.
See § 6.9 for a description of this task.