Abstract:
:An expression for the noise power spectrum of images reconstructed by the discrete filtered backprojection algorithm has been derived. The formulation explicitly includes sampling within the projections, angular sampling, and the two-dimensional sampling implicit in the discrete representation of the image. The effects of interpolation are also considered. Noise power spectra predicted by this analysis differ from those predicted using continuous theory in two respects: they are rotationally asymmetric, and they do not approach zero at zero frequency. Both of these properties can be attributed to two-dimensional aliasing due to pixel sampling. The predictions were confirmed by measurement of noise power spectra of both simulated images and images from a commercial x-ray transmission CT scanner.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Kijewski MF,Judy PFdoi
10.1088/0031-9155/32/5/003subject
Has Abstractpub_date
1987-05-01 00:00:00pages
565-75issue
5eissn
0031-9155issn
1361-6560journal_volume
32pub_type
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