Alignment & Geometry#


The task of the alignment and geometry blocks is to compute and apply geometric transformations to the Image data and sources. For this purpose, an Image contains a transform attrtibute, that corresponds to a scikit-image AffineTransform.

Transform computation blocks#

FAQ: Why computing the transform without applying it?

To control when to apply the transform and to which data. For example, transforming an image data to a common reference (e.g. with interpolation) could be only wanted at the end of a sequence in order to build a stack image.

Other geometry blocks#


Image trimming


Create cutouts around all sources


Set Image sources to reference sources (from a reference Image) aligned to the Image


Create WCS based on a reference containing a valid WCS.

Usually, the transform object stores the geometric transform between the Image and a reference one, so that it is not directly related to the physical WCS of the image (which transforms to physical sky coordinates).