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arXiv 2201.04928math.OCcs.NAmath.NA
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带非匹配伴随的Chambolle-Pock原对偶方法

Chambolle-Pock's Primal-Dual Method with Mismatched Adjoint

Dirk A. Lorenz, Felix Schneppe

摘要:

Chambolle和Pock的原始-对偶方法是一种广泛使用的求解各种最优化问题的算法,这些问题被写成凸-凹鞍点问题。每个更新步骤涉及前向线性算子及其伴随算子的应用。然而,在实际应用中,如计算机断层扫描,它往往是计算上有利的,以取代伴随算子的计算更有效的近似。这导致算法中的伴随失配。在强凸情形下,本文分析了Chambolle-Pock原对偶方法在非匹配伴随存在下的收敛性。我们提出了一个上界的原始解的错误,并推导出步长和温和的条件下,收敛到一个不动点仍然是有保证的。此外,我们显示线性收敛类似的Chambolle-Pock的原始-对偶方法的结果没有伴随失配。此外,我们说明了我们的研究结果的学术和现实世界的启发应用。

英文摘要:

The primal-dual method of Chambolle and Pock is a widely used algorithm to solve various optimization problems written as convex-concave saddle point problems. Each update step involves the application of both the forward linear operator and its adjoint. However, in practical applications like computerized tomography, it is often computationally favourable to replace the adjoint operator by a computationally more efficient approximation. This leads to an adjoint mismatch in the algorithm. In this paper, we analyze the convergence of Chambolle-Pock's primal-dual method under the presence of a mismatched adjoint in the strongly convex setting. We present an upper bound on the error of the primal solution and derive stepsizes and mild conditions under which convergence to a fixed point is still guaranteed. Furthermore we show linear convergence similar to the result of Chambolle-Pock's primal-dual method without the adjoint mismatch. Moreover, we illustrate our results both for an academic and a real-world inspired application.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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