xdem.coreg.BlockwiseCoreg

class xdem.coreg.BlockwiseCoreg(step, subdivision, success_threshold=0.8, n_threads=None, warn_failures=False)

Block-wise co-registration processing class to run a step in segmented parts of the grid.

A processing class of choice is run on an arbitrary subdivision of the raster. When later applying the step the optimal warping is interpolated based on X/Y/Z shifts from the coreg algorithm at the grid points.

For instance: a subdivision of 4 triggers a division of the DEM in four equally sized parts. These parts are then processed separately, with 4 .fit() results. If the subdivision is not divisible by the raster shape, subdivision is made as good as possible to have approximately equal pixel counts.

__init__(step, subdivision, success_threshold=0.8, n_threads=None, warn_failures=False)

Instantiate a blockwise processing object.

Parameters:

• step (Coreg | CoregPipeline) – An instantiated co-registration step object to fit in the subdivided DEMs.

• subdivision (int) – The number of chunks to divide the DEMs in. E.g. 4 means four different transforms.

• success_threshold (float) – Raise an error if fewer chunks than the fraction failed for any reason.

• n_threads (int | None) – The maximum amount of threads to use. Default=auto

• warn_failures (bool) – Trigger or ignore warnings for each exception/warning in each block.

Methods

__init__(step, subdivision[, ...])	Instantiate a blockwise processing object.
apply(elev[, bias_vars, resample, ...])	Apply the estimated transform to a DEM.
copy()	Return an identical copy of the class.
error(reference_elev, to_be_aligned_elev[, ...])	Calculate the error of a coregistration approach.
fit(reference_elev, to_be_aligned_elev[, ...])	Estimate the coregistration transform on the given DEMs.
residuals(reference_elev, to_be_aligned_elev)	Calculate the residual offsets (the difference) between two DEMs after applying the transformation.
stats()	Return statistics for each chunk in the blockwise coregistration.
subdivide_array(shape)	Return the grid subdivision for a given DEM shape.
to_points()	Convert the blockwise coregistration matrices to 3D (source -> destination) points.

Attributes

is_affine

Check if the transform be explained by a 3D affine transform.