applyDcr

lsst.ip.diffim.applyDcr(image, dcr, useInverse=False, splitSubfilters=False, splitThreshold=0.0, doPrefilter=True, order=3)

Shift an image along the X and Y directions.

Parameters:

imagenumpy.ndarray

The input image to shift.

dcrtuple

Shift calculated with calculateDcr. Uses numpy axes ordering (Y, X). If splitSubfilters is set, each element is itself a tuple of two float, corresponding to the DCR shift at the two wavelengths. Otherwise, each element is a float corresponding to the DCR shift at the effective wavelength of the subfilter.

useInversebool, optional

Apply the shift in the opposite direction. Default: False

splitSubfiltersbool, optional

Calculate DCR for two evenly-spaced wavelengths in each subfilter, instead of at the midpoint. Default: False

splitThresholdfloat, optional

Minimum DCR difference within a subfilter required to use splitSubfilters

doPrefilterbool, optional

Spline filter the image before shifting, if set. Filtering is required, so only set to False if the image is already filtered. Filtering takes ~20% of the time of shifting, so if applyDcr will be called repeatedly on the same image it is more efficient to precalculate the filter.

orderint, optional

The order of the spline interpolation, default is 3.

Returns:

shiftedImagenumpy.ndarray

A copy of the input image with the specified shift applied.