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_trafo
RayTransform
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.
- ray_trafo
- Returns:
- tam_danielson_window
ray_trafo.range
element
- tam_danielson_window
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