Wallis, CGR;
Wiaux, Y;
McEwen, JD;
(2017)
Sparse Image Reconstruction on the Sphere: Analysis and Synthesis.
IEEE Transactions on Image Processing
, 26
(11)
pp. 5176-5187.
10.1109/TIP.2017.2716824.
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Abstract
We develop techniques to solve ill-posed inverse problems on the sphere by sparse regularization, exploiting sparsity in both axisymmetric and directional scale-discretized wavelet space. Denoising, in painting, and deconvolution problems and combinations thereof, are considered as examples. Inverse problems are solved in both the analysis and synthesis settings, with a number of different sampling schemes. The most effective approach is that with the most restricted solution-space, which depends on the interplay between the adopted sampling scheme, the selection of the analysis/synthesis problem, and any weighting of the ℓ1 norm appearing in the regularization problem. More efficient sampling schemes on the sphere improve reconstruction fidelity by restricting the solution-space and also by improving sparsity in wavelet space. We apply the technique to denoise Planck 353-GHz observations, improving the ability to extract the structure of Galactic dust emission, which is important for studying Galactic magnetism.
Type: | Article |
---|---|
Title: | Sparse Image Reconstruction on the Sphere: Analysis and Synthesis |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1109/TIP.2017.2716824 |
Publisher version: | http://dx.doi.org/10.1109/TIP.2017.2716824 |
Language: | English |
Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | Harmonic analysis, Wavelet transforms, Manganese, Inverse problems, Image reconstruction, Dictionaries, sampling, spheres, rotation group, Wigner transform |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/1518566 |
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