nabu.pipeline.helical.fbp module

class nabu.pipeline.helical.fbp.BackprojectorHelical(*args, **kwargs)

Bases: CudaBackprojector

This is the Backprojector derived class for helical reconstruction. The modifications are detailed here :

• the backprojection is decoupled from the filtering. This allows, in the pipeline, for doing first a filtering using backprojector_object.sino_filter subobject, then calling backprojector_object.backprojection only after reweigthing the result of the filter_sino method of sino_filter subobject.

• the angles can be resetted on the fly, and the class can work with a variable number of projection. As a matter of fact, with the helical_chunked_regridded.py pipeline, the reconstruction is done each time with the same set of angles, this because of the regridding mechanism. The feature might return useful in the future if alternative approachs are developed again.

This became needed after the _d_sino allocation was removed from the base class

set_custom_angles_and_axis_corrections(angles_rad, x_per_proj)

To arbitrarily change angles :param angles_rad: one angle per each projection in radians :type angles_rad: array of floats :param x_per_proj: each entry is the axis shift for a projection, in pixels. :type x_per_proj: array of floats

backprojection(sino, output=None)

Redefined here to do backprojection only, compare to the base class method.