Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: From variable density sampling to continuous sampling using Markov
  chains   Since its discovery over the last decade, Compressed Sensing (CS) has been
successfully applied to Magnetic Reso- nance Imaging (MRI). It has been shown
to be a powerful way to reduce scanning time without sacrificing image quality.
MR images are actually strongly compressible in a wavelet basis, the latter
being largely incoherent with the k-space or spatial Fourier domain where
acquisition is performed. Nevertheless, since its first application to MRI [1],
the theoretical justification of actual k-space sampling strategies is
questionable. Indeed, the vast majority of k-space sampling distributions have
been heuris- tically designed (e.g., variable density) or driven by
experimental feasibility considerations (e.g., random radial or spiral sampling
to achieve smoothness k-space trajectory). In this paper, we try to reconcile
very recent CS results with the MRI specificities (mag- netic field gradients)
by enforcing the measurements, i.e. samples of k-space, to fit continuous
trajectories. To this end, we propose random walk continuous sampling based on
Markov chains and we compare the reconstruction quality of this scheme to the
state- of-the art.

22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex