DESIGN OF SAMPLING MATRICES IN GRAPH FREQUENCY DOMAIN FOR GRAPH SIGNAL PROCESSING

We propose a novel sampling method of graph signals that simultaneously inherits the characteristics of the sampled signals in the vertex and graph frequency domains. In the conventional sampling of graph signals, the sampled signal can retain the characteristics only in one (vertex or graph frequency) domain, but it is not suitable for another domain. The proposed method forms an optimization problem to design appropriate sampling matrices in the graph frequency domain for inheriting the characteristics of the sampled signals in the vertex domain. We perform downsampling of graph signals based on the proposed approach and apply it to denoising with graph Laplacian pyramid along with the comparison to the existing methods.