Abstract
This work is concerned with linear inverse problems where a distributed parameter is known a priori to only take on values from a given discrete set. This property can be promoted in Tikhonov regularization with the aid of a suitable convex but nondifferentiable regularization term. This allows applying standard approaches to show well-posedness and convergence rates in Bregman distance. Using the specific properties of the regularization term, it can be shown that convergence (albeit without rates) actually holds pointwise. Furthermore, the resulting Tikhonov functional can be minimized efficiently using a semi-smooth Newton method. Numerical examples illustrate the properties of the regularization term and the numerical solution.
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E. Bae, X.C. Tai, Graph cut optimization for the piecewise constant level set method applied to multiphase image segmentation (Springer, Berlin/Heidelberg, 2009), pp. 1–13, http://doi.org/10.1007/978-3-642-02256-2_1
V. Barbu, T. Precupanu, Convexity and Optimization in Banach Spaces. Springer Monographs in Mathematics, 4th edn. (Springer, Dordrecht, 2012). http://doi.org/10.1007/978-94-007-2247-7
H.H. Bauschke, P.L. Combettes, Convex Analysis and Monotone Operator Theory in Hilbert Spaces. CMS Books in Mathematics/Ouvrages de Mathématiques de la SMC (Springer, New York, 2011). http://doi.org/10.1007/978-1-4419-9467-7
M. Bergounioux, F. Tröltzsch, Optimality conditions and generalized bang-bang principle for a state-constrained semilinear parabolic problem. Numer. Funct. Anal. Optim. 17(5–6), 517–536 (1996). htttp://doi.org/10.1080/01630569608816708
L.M. Bregman, The relaxation method of finding the common point of convex sets and its application to the solution of problems in convex programming. USSR Comput. Math. Math. Phys. 7(3), 200–217 (1967)
M. Burger, S. Osher, Convergence rates of convex variational regularization. Inverse Prob. 20(5), 1411 (2004). http://doi.org/10.1088/0266-5611/20/5/005
X. Cai, R. Chan, T. Zeng, A two-stage image segmentation method using a convex variant of the Mumford–Shah model and thresholding. SIAM J. Imag. Sci. 6(1), 368–390 (2013). http://doi.org/10.1137/120867068
C. Clason, K. Kunisch, Multi-bang control of elliptic systems. Ann. Inst. H. Poincaré Anal. Non Linéaire 31(6), 1109–1130 (2014). http://doi.org/10.1016/j.anihpc.2013.08.005
C. Clason, K. Kunisch, A convex analysis approach to multi-material topology optimization. ESAIM: Math. Model. Numer. Anal. 50(6), 1917–1936 (2016). http://doi.org/10.1051/m2an/2016012
C. Clason, C. Tameling, B. Wirth, Vector-valued multibang control of differential equations (2016). arXiv 1611(07853). http://www.arxiv.org/abs/1611.07853
C. Clason, K. Ito, K. Kunisch, A convex analysis approach to optimal controls with switching structure for partial differential equations. ESAIM Control, Optimisation and Calculus of Variations 22(2), 581–609 (2016). http://doi.org/10.1051/cocv/2015017
I. Ekeland, R. Témam, Convex Analysis and Variational Problems. Classics in Applied Mathematics, vol. 28 (SIAM, Philadelphia, 1999). http://doi.org/10.1137/1.9781611971088
J. Flemming, B. Hofmann, Convergence rates in constrained Tikhonov regularization: equivalence of projected source conditions and variational inequalities. Inverse Prob. 27(8), 085001 (2011). http://doi.org/10.1088/0266-5611/27/8/085001
B. Goldluecke, D. Cremers, Convex relaxation for multilabel problems with product label spaces (Springer, Berlin/Heidelberg, 2010), pp. 225–238. http://doi.org/10.1007/978-3-642-15555-0_17
B. Hofmann, B. Kaltenbacher, C. Pöschl, O. Scherzer, A convergence rates result for Tikhonov regularization in Banach spaces with non-smooth operators. Inverse Prob. 23(3), 987–1010 (2007). http://doi.org/10.1088/0266-5611/23/3/009
H. Ishikawa, Exact optimization for Markov random fields with convex priors. IEEE Trans. Pattern Anal. Mach. Intell. 25(10), 1333–1336 (2003). http://doi.org/10.1109/TPAMI.2003.1233908
K. Ito, B. Jin, Inverse Problems: Tikhonov Theory and Algorithms. Series on Applied Mathematics, vol. 22 (World Scientific, Singapore, 2014). http://doi.org/10.1142/9789814596206_0001
K. Ito, K. Kunisch, Lagrange Multiplier Approach to Variational Problems and Applications, Advances in Design and Control, vol. 15 (SIAM, Philadelphia, PA, 2008). http://doi.org/10.1137/1.9780898718614
J. Lellmann, C. Schnörr, Continuous multiclass labeling approaches and algorithms. SIAM J. Imag. Sci. 4(4), 1049–1096 (2011). http://doi.org/10.1137/100805844
E. Resmerita, Regularization of ill-posed problems in Banach spaces: convergence rates. Inverse Prob. 21(4), 1303 (2005). http://doi.org/10.1088/0266-5611/21/4/007
O. Scherzer, M. Grasmair, H. Grossauer, M. Haltmeier, F. Lenzen, Variational Methods in Imaging. Applied Mathematical Sciences, vol. 167 (Springer, Cham, 2009). http://doi.org/10.1007/978-0-387-69277-7
W. Schirotzek, Nonsmooth Analysis. Universitext (Springer, Berlin, 2007). http://doi.org/10.1007/978-3-540-71333-3
T. Schuster, B. Kaltenbacher, B. Hofmann, K.S. Kazimierski, Regularization Methods in Banach Spaces. Radon Series on Computational and Applied Mathematics, vol. 10 (De Gruyter, Berlin, 2012). http://doi.org/10.1515/9783110255720
F. Tröltzsch, A minimum principle and a generalized bang-bang principle for a distributed optimal control problem with constraints on control and state. Z. Angew. Math. Mech. 59(12), 737–739 (1979). http://doi.org/10.1002/zamm.19790591208
F. Tröltzsch, Optimal Control of Partial Differential Equations: Theory, Methods and Applications, Translated from the German by Jürgen Sprekels (American Mathematical Society, Providence, 2010). http://doi.org/10.1090/gsm/112
M. Ulbrich, Semismooth Newton Methods for Variational Inequalities and Constrained Optimization Problems in Function Spaces. MOS-SIAM Series on Optimization, vol. 11 (SIAM, Philadelphia, PA, 2011). http://doi.org/10.1137/1.9781611970692
L.A. Vese, T.F. Chan, A multiphase level set framework for image segmentation using the Mumford and Shah model. Int. J. Comput. Vis. 50(3), 271–293 (2002). http://doi.org/10.1023/A:1020874308076
D. Wachsmuth, G. Wachsmuth, Regularization error estimates and discrepancy principle for optimal control problems with inequality constraints. Control. Cybern. 40(4), 1125–1158 (2011)
G. Wachsmuth, D. Wachsmuth, Convergence and regularization results for optimal control problems with sparsity functional. ESAIM Control Optim. Calc. Var. 17(3), 858–886 (2011). http://doi.org/10.1051/cocv/2010027
Acknowledgements
This work was supported by the German Science Fund (DFG) under grant CL 487/1-1. The authors also wish to thank Daniel Wachsmuth for several helpful remarks.
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Clason, C., Do, T.B.T. (2018). Convex Regularization of Discrete-Valued Inverse Problems. In: Hofmann, B., Leitão, A., Zubelli, J. (eds) New Trends in Parameter Identification for Mathematical Models. Trends in Mathematics. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-70824-9_2
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