Blot Algorithm for Cutouts

A module that provides blotting algorithm for image cutouts and a default WCS-based coordinate mapping class.

Author

Mihai Cara (for help, contact HST Help Desk)

License

LICENSE

class subpixal.blot.BlotWCSMap(source_cutout, target_cutout)

Coordinate mapping class that performs coordinate transformation from the source cutout to the “target” cutout. The target cutout simply provides a coordinate system. This class implements coordinate transformation in the __call__() method.

Parameters

source_cutoutCutout

A cutout that defines source coordinate system (input to the __call__(x, y) method).

target_cutoutCutout

A cutout that provides target coordinates system to which source coordinates need to be mapped.

subpixal.blot.blot_cutout(source_cutout, target_cutout, interp='poly5', sinscl=1.0, wcsmap=None)

Performs ‘blot’ operation to create a single blotted image from a single source image. All distortion information is assumed to be included in the WCS of the source_cutout and target_cutout.

Parameters

source_cutoutCutout

Cutout that needs to be “blotted”. Provides source image for the “blot” operation and a WCS.

target_cutoutCutout

Cutout to which source_cutout will be “blotted”. This cutout provides a WCS and an output grid.

interp{‘nearest’, ‘linear’, ‘poly3’, ‘poly5’, ‘spline3’, ‘sinc’}, optional

Form of interpolation to use when blotting pixels.

sinsclfloat, optional

Scale for sinc interpolation kernel (in output, blotted pixels)

wcsmapcallable, optional

Custom mapping class to use to provide transformation from source cutout image coordinates to target cutout image coordinates.