Correlation Preserving Sparse Coding Over Multi-level Dictionaries for Image Denoising
This is an incremental improvement for image denoising, addressing a specific bottleneck in dictionary-driven methods.
The paper tackles image denoising by proposing a correlation preserving sparse coding method with graph-based and locality-constrained regularizers to address unstable correlations in dictionaries, achieving state-of-the-art performance in PSNR and visual quality.
In this letter, we propose a novel image denoising method based on correlation preserving sparse coding. Because the instable and unreliable correlations among basis set can limit the performance of the dictionary-driven denoising methods, two effective regularized strategies are employed in the coding process. Specifically, a graph-based regularizer is built for preserving the global similarity correlations, which can adaptively capture both the geometrical structures and discriminative features of textured patches. In particular, edge weights in the graph are obtained by seeking a nonnegative low-rank construction. Besides, a robust locality-constrained coding can automatically preserve not only spatial neighborhood information but also internal consistency present in noisy patches while learning overcomplete dictionary. Experimental results demonstrate that our proposed method achieves state-of-the-art denoising performance in terms of both PSNR and subjective visual quality.