Describing the solutions of inverse problems arising in signal or image processing is an important issue both for theoretical and numerical purposes. We propose a principle which describes the solutions to convex variational problems involving a finite number of measurements. We discuss its optimality on various problems concerning the recovery of Radon measures.

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V. Duval. “An Epigraphical Approach to the Representer Theorem.” Journal of Convex Analysis 28 (2021), No. 3, 819–836. https://doi.org/10.68381/jca28047