A Fast Thresholded Landweber Algorithm for Wavelet-Regularized Multidimensional Deconvolution
C. Vonesch, M. Unser
IEEE Transactions on Image Processing, vol. 17, no. 4, pp. 539–549, April 2008.
We present a fast variational deconvolution algorithm that minimizes a quadratic data term subject to a regularization on the ℓ1-norm of the wavelet coefficients of the solution. Previously available methods have essentially consisted in alternating between a Landweber iteration and a wavelet-domain soft-thresholding operation. While having the advantage of simplicity, they are known to converge slowly. By expressing the cost functional in a Shannon wavelet basis, we are able to decompose the problem into a series of subband-dependent minimizations. In particular, this allows for larger (subband-dependent) step sizes and threshold levels than the previous method. This improves the convergence properties of the algorithm significantly. We demonstrate a speed-up of one order of magnitude in practical situations. This makes wavelet-regularized deconvolution more widely accessible, even for applications with a strong limitation on computational complexity. We present promising results in 3-D deconvolution microscopy, where the size of typical data sets does not permit more than a few tens of iterations.
@ARTICLE(http://bigwww.epfl.ch/publications/vonesch0801.html, AUTHOR="Vonesch, C. and Unser, M.", TITLE="A Fast Thresholded {L}andweber Algorithm for Wavelet-Regularized Multidimensional Deconvolution", JOURNAL="{IEEE} Transactions on Image Processing", YEAR="2008", volume="17", number="4", pages="539--549", month="April", note="")