Figure 3
From: Adaptive example-based super-resolution using kernel PCA with a novel classification approach
Overview of the algorithm for estimating missing high-frequency components. The direct estimation of HR patches from their LR patches is infeasible since the matrix Σ is singular and its inverse matrix cannot be obtained. Thus, the proposed method projects those two patches onto the low-dimensional subspaces and enables the derivation of the projection corresponding to the inverse matrix of Σ.