“…In this paper, we provide theoretical insights on the pre-image problem and its resolution. This problem has been known for about 20 years [33], and is still of great interest nowadays, as shown recently in many frameworks: when dealing with nonlinear dictionary learning [40,31] and matrix completion [17]; when dealing with structured input spaces, such as in interpretable time series analytics [36], graph edit distances [23,24], representation learning on graphs [10] and structured prediction [15]; generative machines including generative kernel PCA [29] and multiview generation [30].…”