Title
Nonlinear kernel backprojection for computed tomography
Abstract
In this paper, we propose a kernel backprojection method for computed tomography. The classical backprojection method estimates an unknown pixel value by the summation of the projection values with linear weights, while our kernel backprojection is a generalized version of the classic approach, in which we compute the weights from a kernel (weight) function. The generalization reveals that the performance of the backprojection operation strongly depends on the choice of the kernel, and a good choice of the kernels effectively suppresses both noise and streak artifacts while preserving major structures of the unknown phantom. The proposed method is a two-step procedure where we first compute a preliminary estimate of the phantom (a "pilot"), from which we compute the kernel weights. From these kernel weights we then re-estimate the phantom, arriving at a much improved result. The experimental results show that our approach significantly enhances the backprojection operation not only numerically but also visually.
Year
DOI
Venue
2010
10.1109/ICASSP.2010.5495184
ICASSP
Keywords
Field
DocType
computerised tomography,image reconstruction,computed tomography,kernel weight function,linear weights,nonlinear kernel backprojection,phantom,projection values,unknown pixel value,filtered backprojection,kernel regression,nonlinear filters,projection reconstruction,tomography
Kernel (linear algebra),Iterative reconstruction,Mathematical optimization,Radial basis function kernel,Iterative method,Imaging phantom,Variable kernel density estimation,Compressed sensing,Mathematics,Kernel regression
Conference
ISSN
Citations 
PageRank 
1520-6149
1
0.36
References 
Authors
0
2
Name
Order
Citations
PageRank
Hiroyuki Takeda12268.63
Peyman Milanfar23284155.61