查看更多>>摘要：We propose a sampling set selection method for graph signals under arbitrary signal priors. Most approaches of graph signal sampling assume that signals are bandlimited. However, in practical situations, there exist many full-band graph signals like piecewise smooth/constant signals. Our sampling set selection method allows for arbitrary graph signal models as long as they are linear. This can be derived from a generalized sampling framework. In contrast to existing works, we focus on the direct sum condition between sampling and reconstruction subspaces where the direct sum condition plays a key role for the best possible recovery of sampled signals. We also design a fast sampling set selection algorithm based on the proposed method with the Neumann series approximation. In sampling and recovery experiments, we validate the effectiveness of the proposed method for several graph signal models.
查看更多>>摘要：This work proposes a novel image denoising technique inspired by the deep image prior (DIP) method. Our contribution is to increase the interpretability of the network by proposing to use the Stein's unbiased risk estimator (SURE) to realize self-supervised learning of image restoration. As a result, the number of parameters is decreased while keeping the performance. The conventional DIP accepts random input to generate restored image and has an advantage that no training data is requested. However, there is a problem that the interpretability is low. As a result, the network should prepare redundant design parameters. In this work, we replace the loss function from mean-squared error (MSE) to SURE. This replacement allows us to interpret the reason why a random input is needed. As well, we also introduce the interscale linear expansion of the thresholding (LET) in our network to exploit the extracted features. In order to avoid using group delay compensation, we construct a structured DIP by using hierarchical non-separable oversampled lapped transform (NSOLT) with the symmetric property. By showing some simulation results, the significance of the proposed method is verified.
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