Mercurial > hg > smallbox
comparison util/sparco utils/genSampling.m @ 77:62f20b91d870
add routines from sparco problems privite folder to {root}\util
some changes to ksvd vs rlsdla image denoising example
author | Ivan <ivan.damnjanovic@eecs.qmul.ac.uk> |
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date | Fri, 25 Mar 2011 14:01:50 +0000 |
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76:d052ec5b742f | 77:62f20b91d870 |
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1 function [minIntrVec,stat,actpctg] = genSampling(pdf,iter,tol) | |
2 | |
3 %[mask,stat,N] = genSampling(pdf,iter,tol) | |
4 % | |
5 % a monte-carlo algorithm to generate a sampling pattern with | |
6 % minimum peak interference. The number of samples will be | |
7 % sum(pdf) +- tol | |
8 % | |
9 % pdf - probability density function to choose samples from | |
10 % iter - number of tries | |
11 % tol - the deviation from the desired number of samples in samples | |
12 % | |
13 % returns: | |
14 % mask - sampling pattern | |
15 % stat - vector of min interferences measured each try | |
16 % actpctg - actual undersampling factor | |
17 % | |
18 % (c) Michael Lustig 2007 | |
19 | |
20 % This file is used with the kind permission of Michael Lustig | |
21 % (mlustig@stanford.edu), and originally appeared in the | |
22 % SparseMRI toolbox, http://www.stanford.edu/~mlustig/ . | |
23 % | |
24 % $Id: genSampling.m 1040 2008-06-26 20:29:02Z ewout78 $ | |
25 | |
26 % h = waitbar(0); | |
27 | |
28 pdf(find(pdf>1)) = 1; | |
29 K = sum(pdf(:)); | |
30 | |
31 minIntr = 1e99; | |
32 minIntrVec = zeros(size(pdf)); | |
33 | |
34 for n=1:iter | |
35 tmp = zeros(size(pdf)); | |
36 while abs(sum(tmp(:)) - K) > tol | |
37 tmp = rand(size(pdf))<pdf; | |
38 end | |
39 | |
40 TMP = ifft2(tmp./pdf); | |
41 if max(abs(TMP(2:end))) < minIntr | |
42 minIntr = max(abs(TMP(2:end))); | |
43 minIntrVec = tmp; | |
44 end | |
45 stat(n) = max(abs(TMP(2:end))); | |
46 % waitbar(n/iter,h); | |
47 end | |
48 | |
49 actpctg = sum(minIntrVec(:))/prod(size(minIntrVec)); | |
50 | |
51 % close(h); | |
52 | |
53 |