Over the past years, progressive methods have demonstrated promising performance in single image de-raining task. Nonetheless, current methods still struggle to precisely remove rain and preserve more image details during the progressive de-raining process, resulting in undesirable local artifacts or image detail loss. To tackle these limitations, a novel progressive approach, called Uncertainty-driven Progressive Single Image De-raining (UPSID), is proposed. Firstly, a powerful internal-and-external dense sub-network is devised, which effectively integrates three proper and flexible components, including dense connection, long short-term memory, and channel attention. Subsequently, the sub-network is further unfolded into multiple recurrent stages to form a progressive de-raining network. Finally, the overall progressive de-raining network is trained with an adaptive weighted loss to focus more on challenging pixels that characterize rain or texture/edge regions. Extensive quantitative and qualitative experiments confirm that the proposed UPSID outperforms multiple state-of-the-art algorithms, including single-stage, progressive, and uncertainty-driven single image de-raining methods. Additionally, this article also demonstrates the superiority of UPSID for other similar image restoration tasks such as single image de-snowing. The code will be publicly available at https://github.com/Lcai-QZ/UPSID .

Multi-scale architectures and attention modules have shown effectiveness in many deep learning-based image de-raining methods. However, manually designing and integrating these two components into a neural network requires a bulk of labor and extensive expertise. In this article, a high-performance multi-scale attentive neural architecture search (MANAS) framework is technically developed for image de-raining. The proposed method formulates a new multi-scale attention search space with multiple flexible modules that are favorite to the image de-raining task. Under the search space, multi-scale attentive cells are built, which are further used to construct a powerful image de-raining network. The internal multi-scale attentive architecture of the de-raining network is searched automatically through a gradient-based search algorithm, which avoids the daunting procedure of the manual design to some extent. Moreover, in order to obtain a robust image de-raining model, a practical and effective multi-to- one training strategy is also presented to allow the de-raining network to get sufficient background information from multiple rainy images with the same background scene, and meanwhile, multiple loss functions including external loss, internal loss, architecture regularization loss, and model complexity loss are jointly optimized to achieve robust de-raining performance and controllable model complexity. Extensive experimental results on both synthetic and realistic rainy images, as well as the down-stream vision applications (i.e., objection detection and segmentation) consistently demonstrate the superiority of our proposed method. The code is publicly available athttps://github.com/lcai-gz/MANAS.

Single image de-raining is an important and highly challenging problem. To address this problem, some depth or density guided single-image de-raining methods have been developed with encouraging performance. However, these methods individually use the depth or the density to guide the network to conduct image de-raining. In this paper, a noveljoint depth and density guided de-raining(JDDGD) method is technically developed. The JDDGD starts with adepth-density inference network(DDINet) to extract the depth and density information from an input rainy image, followed by adepth-density-basedconditional generative adversarial network (DD-CGAN) to exploit the depth and density information provided by DDINet to achieve adaptive rain streak and fog removal. To prevent the spatially-varying local artifacts, an effectiveglobal-local discriminatorsstructure is introduced in the proposed DD-CGAN to globally and locally inspect the generated images. In addition, multiple loss functions includingmulti-scale pixel loss,multi-scale perceptual loss, andglobal-local generative adversarial lossare also jointly used to train our model to achieve the best performance. Both quantitative and qualitative results show that the proposed JDDGD method achieves superior performance than previousnon-guided,density-guided, anddepth-guided de-rainingmethods.

This paper develops an algorithm to effectively explore the advantages of both sparse vector recovery methods and generative model-based recovery methods for solving compressed sensing recovery problem. The proposed algorithm mainly consists of two steps. In the first step, a network-based projected gradient descent (NPGD) is introduced to solve a non-convex optimization problem, obtaining a preliminary recovery of the original signal. Then with the obtained preliminary recovery, a l1norm regularized optimization problem is solved by optimizing for sparse deviation vectors. Experimental results on two bench-mark datasets for image compressed sensing clearly demonstrate that the proposed recovery algorithm can bring about high computation speed, while decreasing the reconstruction error continuously with increasing the number of measurements.

As a prior knowledge, non‐local self‐similarity (NSS) has been widely utilised in ill‐posed problems. Actually, similar textures appear not only in a single scale, but also in different scales. Unlike most existing patch‐based methods that only explore NSS in the same scale, a multi‐scale patches based image denoising algorithm is proposed in this study. The authors have designed a multi‐scale strategy to expand the search space of block‐matching, which will increase the probability of finding more similar patches. After that, the weighted nuclear norm minimisation (WNNM) algorithm is employed to reveal latent clean patches. With the join of the multi‐scale framework, the performance of WNNM can be improved. The proposed algorithm can be used to solve NSS‐based image restoration tasks. In this study, mainly image denoising is studied, and its effectiveness is derived through experiments on widely used test images.

The over‐relaxed monotone fast iterative shrinkage‐thresholding algorithm (OMFISTA) needs to satisfy a complex convergence condition with respect to its additional parameters. To simplify the convergence condition, this study proposes a new OMFISTA, termed OMFISTAv2, using a parameter setting strategy which will derive a simple sufficient condition with respect to the additional parameters to guarantee the convergence of OMFISTAv2. Moreover, the authors find experimentally that OMFISTAv2 can accelerate MFISTA in some cases where the system matrix is ill‐conditioned or rank‐deficient, while OMFISTA cannot.