tam_danielson_window

odl.tomo.analytic.filtered_back_projection.tam_danielson_window(ray_trafo, smoothing_width=0.05, n_pi=1)[source]

Create Tam-Danielson window from a RayTransform.

The Tam-Danielson window is an indicator function on the minimal set of data needed to reconstruct a volume from given data. It is useful in analytic reconstruction methods such as FBP to give a more accurate reconstruction.

See [TAM1998] for more informationon the window. See [PKGT2000] for information on the n_pi parameter.

Parameters:
ray_trafoRayTransform

The ray transform for which to compute the window.

smoothing_widthpositive float, optional

Width of the smoothing applied to the window's edges given as a fraction of the width of the full window.

n_piodd int, optional

Total number of half rotations to include in the window. Values larger than 1 should be used if the pitch is much smaller than the detector height.

Returns:
tam_danielson_windowray_trafo.range element

See also

fbp_op

Filtered back-projection operator from RayTransform

tam_danielson_window

Weighting for short scan data

odl.tomo.geometry.conebeam.ConeBeamGeometry

Primary use case for this window function.

References

[TSS1998] Tam, K C, Samarasekera, S and Sauer, F. Exact cone beam CT with a spiral scan. Physics in Medicine & Biology 4 (1998), p 1015. https://dx.doi.org/10.1088/0031-9155/43/4/028

[PKGT2000] Proksa R, Köhler T, Grass M, Timmer J. The n-PI-method for helical cone-beam CT IEEE Trans Med Imaging. 2000 Sep;19(9):848-63. https://www.ncbi.nlm.nih.gov/pubmed/11127600