论文标题
学习非本地稀疏和低级模型以进行图像压缩感应
Learning Nonlocal Sparse and Low-Rank Models for Image Compressive Sensing
论文作者
论文摘要
与Nyquist-Shannon采样定理建议的精确重建图像相比,压缩感应(CS)方案的利用要少得多,这吸引了计算成像群落中的大量关注。尽管经典图像CS方案使用分析变换或基础采用了稀疏性,但近年来,基于学习的方法越来越流行。这样的方法可以通过优化其稀疏表示或学习深神经网络,同时保留已知或建模的感应过程,从而有效地对图像贴片的结构进行建模。除了利用局部图像属性外,高级CS方案还采用非局部图像建模,通过在图像的不同位置提取相似或高度相关的斑块以形成一个组以共同处理。最新的基于学习的CS方案采用了非本地结构稀疏性,使用组稀疏表示(GSR)和/或低级别(LR)建模,这些模型在各种计算成像和图像处理应用程序中都表现出了有希望的性能。本文回顾了图像CS任务中的一些最新作品,重点是基于高级GSR和LR的方法。此外,我们提出了一个统一的框架,用于结合各种GSR和LR模型,并讨论GSR和LR模型之间的关系。最后,我们讨论了该领域的开放问题和未来方向。
The compressive sensing (CS) scheme exploits much fewer measurements than suggested by the Nyquist-Shannon sampling theorem to accurately reconstruct images, which has attracted considerable attention in the computational imaging community. While classic image CS schemes employed sparsity using analytical transforms or bases, the learning-based approaches have become increasingly popular in recent years. Such methods can effectively model the structures of image patches by optimizing their sparse representations or learning deep neural networks, while preserving the known or modeled sensing process. Beyond exploiting local image properties, advanced CS schemes adopt nonlocal image modeling, by extracting similar or highly correlated patches at different locations of an image to form a group to process jointly. More recent learning-based CS schemes apply nonlocal structured sparsity prior using group sparse representation (GSR) and/or low-rank (LR) modeling, which have demonstrated promising performance in various computational imaging and image processing applications. This article reviews some recent works in image CS tasks with a focus on the advanced GSR and LR based methods. Furthermore, we present a unified framework for incorporating various GSR and LR models and discuss the relationship between GSR and LR models. Finally, we discuss the open problems and future directions in the field.