A Two-Step Inertial Picard–CR Framework for Fixed Point Problems with Applications to Optimization and Image Recovery
Main Article Content
Abstract
This paper proposes a two-step inertial Picard–CR iterative framework for approximating common fixed points of a countable family of nonexpansive mappings in real Hilbert spaces. The method combines a viscosity approximation with two inertial corrections and a Picard–CR-type fixed-point update. Under suitable control conditions and an asymptotic compatibility requirement on the intermediate iterates, strong convergence to the viscosity-selected common fixed point is established. The abstract fixed-point result is then specialized to a convex bilevel optimization problem through a family of forward–backward operators. An image-restoration experiment based on a regularized inverse problem is also presented. Numerical comparisons with several forward–backward and accelerated schemes illustrate the computational behavior of the proposed approach.
Article Details
References
- J.A. Abuchu, A.E. Ofem, G.C. Ugwunnadi, O.K. Narain, A. Hussain, Hybrid Alternated Inertial Projection and Contraction Algorithm for Solving Bilevel Variational Inequality Problems, J. Math. 2023 (2023), 1–23. https://doi.org/10.1155/2023/3185746.
- H. Attouch, J. Peypouquet, The Rate of Convergence of Nesterov's Accelerated Forward-Backward Method is Actually Faster Than 1/k^2, SIAM J. Optim. 26 (2016), 1824–1834. https://doi.org/10.1137/15M1046095.
- H.H. Bauschke, P.L. Combettes, Convex Analysis and Monotone Operator Theory in Hilbert Spaces, 2nd ed., Springer International Publishing, 2017. https://doi.org/10.1007/978-3-319-48311-5.
- A. Beck, M. Teboulle, A Fast Iterative Shrinkage-Thresholding Algorithm for Linear Inverse Problems, SIAM J. Imaging Sci. 2 (2009), 183–202. https://doi.org/10.1137/080716542.
- Y. Bengio, Gradient-Based Optimization of Hyperparameters, Neural Comput. 12 (2000), 1889–1900. https://doi.org/10.1162/089976600300015187.
- Y. Censor, S.A. Zenios, Parallel Optimization: Theory, Algorithms, and Applications, Oxford University Press, 1997. https://doi.org/10.1093/oso/9780195100624.001.0001.
- A. Chambolle, T. Pock, A First-Order Primal-Dual Algorithm for Convex Problems with Applications to Imaging, J. Math. Imaging Vis. 40 (2011), 120–145. https://doi.org/10.1007/s10851-010-0251-1.
- P.L. Combettes, J.-C. Pesquet, Proximal Splitting Methods in Signal Processing, in: H.H. Bauschke, R.S. Burachik, P.L. Combettes, V. Elser, D.R. Luke, H. Wolkowicz (eds), Fixed-Point Algorithms for Inverse Problems in Science and Engineering, Springer Optimization and Its Applications, Springer, New York, pp. 185–212, (2011). https://doi.org/10.1007/978-1-4419-9569-8_10.
- P. Duan, Y. Zhang, Alternated and Multi-Step Inertial Approximation Methods for Solving Convex Bilevel Optimization Problems, Optimization 72 (2023), 2517–2545. https://doi.org/10.1080/02331934.2022.2069022.
- F. Facchinei, J.-S. Pang, Finite-Dimensional Variational Inequalities and Complementarity Problems, Volume I, Springer New York, 2003. https://doi.org/10.1007/b97543.
- F. Facchinei, J.-S. Pang, Finite-Dimensional Variational Inequalities and Complementarity Problems, Volume II, Springer New York, 2003. https://doi.org/10.1007/b97544.
- L. Franceschi, P. Frasconi, S. Salzo, R. Grazzi, M. Pontil, Bilevel Programming for Hyperparameter Optimization and Meta-Learning, Proc. Mach. Learn. Res. 80 (2018), 1568–1577. https://proceedings.mlr.press/v80/franceschi18a.html.
- K. Goebel, W.A. Kirk, Topics in Metric Fixed Point Theory, Cambridge University Press, 1990. https://doi.org/10.1017/CBO9780511526152.
- P.C. Hansen, Rank-Deficient and Discrete Ill-Posed Problems: Numerical Aspects of Linear Inversion, Society for Industrial and Applied Mathematics, 1998. https://doi.org/10.1137/1.9780898719697.
- D. Kinderlehrer, G. Stampacchia, An Introduction to Variational Inequalities and Their Applications, Society for Industrial and Applied Mathematics, 2000. https://doi.org/10.1137/1.9780898719451.
- M.A. Krasnosel'skii, Two Remarks on the Method of Successive Approximations, Usp. Mat. Nauk 10 (1955), 123–127. https://www.mathnet.ru/eng/rm7954.
- P.-L. Lions, B. Mercier, Splitting Algorithms for the Sum of Two Nonlinear Operators, SIAM J. Numer. Anal. 16 (1979), 964–979. https://doi.org/10.1137/0716071.
- D.A. Lorenz, T. Pock, An Inertial Forward-Backward Algorithm for Monotone Inclusions, J. Math. Imaging Vis. 51 (2015), 311–325. https://doi.org/10.1007/s10851-014-0523-2.
- W.R. Mann, Mean Value Methods in Iteration, Proc. Amer. Math. Soc. 4 (1953), 506–510. https://doi.org/10.1090/S0002-9939-1953-0054846-3.
- G. Marino, H.-K. Xu, A General Iterative Method for Nonexpansive Mappings in Hilbert Spaces, J. Math. Anal. Appl. 318 (2006), 43–52. https://doi.org/10.1016/j.jmaa.2005.05.028.
- A. Moudafi, Viscosity Approximation Methods for Fixed-Points Problems, J. Math. Anal. Appl. 241 (2000), 46–55. https://doi.org/10.1006/jmaa.1999.6615.
- Y.E. Nesterov, A Method for Solving the Convex Programming Problem with Convergence Rate O(1/k^2), Dokl. Akad. Nauk SSSR, 269 (1983), 543–547. https://www.mathnet.ru/eng/dan46009.
- A.E. Ofem, J.A. Abuchu, G.C. Ugwunnadi, H.A. Nabwey, A. Adamu, O.K. Narain, Double Inertial Steps Extragadient-Type Methods for Solving Optimal Control and Image Restoration Problems, AIMS Math. 9 (2024), 12870–12905. https://doi.org/10.3934/math.2024629.
- A.E. Ofem, J.A. Abuchu, G.C. Ugwunnadi, O.K. Narain, H. Aydi, C. Park, A Mixed-Type Picard-S Iterative Method for Estimating Common Fixed Points in Hyperbolic Spaces, J. Appl. Anal. Comput. 14 (2024), 1302–1329. https://doi.org/10.11948/20230125.
- A.E. Ofem, A.A. Mebawondu, G.C. Ugwunnadi, P. Cholamjiak, O.K. Narain, A Novel Method for Solving Split Variational Inequality and Fixed Point Problems, Appl. Anal. 104 (2025), 3717–3747. https://doi.org/10.1080/00036811.2025.2505615.
- A.E. Ofem, Z. Ali, R. George, J. George, A Relaxed Two-Inertial Subgradient Extragradient Method for Solving Equilibrium and Fixed Point Problems with Applications, Eur. J. Pure Appl. Math. 19 (2026), 7277. https://doi.org/10.29020/nybg.ejpam.v19i1.7277.
- N. Parikh, S. Boyd, Proximal Algorithms, Found. Trends Optim. 1 (2014), 127–239. https://doi.org/10.1561/2400000003.
- F. Pedregosa, Hyperparameter Optimization with Approximate Gradient, Proc. Mach. Learn. Res. 48 (2016), 737–746. https://proceedings.mlr.press/v48/pedregosa16.html.
- B.T. Polyak, Some Methods of Speeding up the Convergence of Iteration Methods, USSR Comput. Math. Math. Phys. 4 (1964), 1–17. https://doi.org/10.1016/0041-5553(64)90137-5.
- P. Lamba, A. Panwar, A Picard S* Iterative Algorithm for Approximating Fixed Points of Generalized α-Nonexpansive Mappings, J. Math. Comput. Sci. 11 (2021), 2874–2892. https://doi.org/10.28919/jmcs/5624.
- R.T. Rockafellar, Convex Analysis, Princeton University Press, 1970. https://doi.org/10.1515/9781400873173.
- S. Sabach, S. Shtern, A First Order Method for Solving Convex Bilevel Optimization Problems, SIAM J. Optim. 27 (2017), 640–660. https://doi.org/10.1137/16M105592X.
- Y. Shehu, P.T. Vuong, A. Zemkoho, An Inertial Extrapolation Method for Convex Simple Bilevel Optimization, Optim. Methods Softw. 36 (2021), 1–19. https://doi.org/10.1080/10556788.2019.1619729.
- P. Thongpaen, W. Inthakon, A. Kaewkhao, S. Suantai, Convex Minimization Problems Based on an Accelerated Fixed Point Algorithm with Applications to Image Restoration Problems, J. Nonlinear Var. Anal. 7 (2023), 87–101. https://doi.org/10.23952/jnva.7.2023.1.06.
- R. Tibshirani, Regression Shrinkage and Selection via the Lasso, J. R. Stat. Soc. Ser. B Stat. Methodol. 58 (1996), 267–288. https://doi.org/10.1111/j.2517-6161.1996.tb02080.x.
- A.N. Tikhonov, V.Y. Arsenin, Solutions of Ill-Posed Problems, V. H. Winston & Sons, 1977.
- H.K. Xu, Viscosity Approximation Methods for Nonexpansive Mappings, J. Math. Anal. Appl. 298 (2004), 279–291. https://doi.org/10.1016/j.jmaa.2004.04.059.