Recently, deep convolutional neural networks (CNNs) have been widely explored in single image super-resolution (SISR) and contribute remarkable progress. However, most of the existing CNNs-based SISR methods do not adequately explore contextual information in the feature extraction stage and pay little attention to the final high-resolution (HR) image reconstruction step, hence hindering the desired SR performance. To address the above two issues, in this paper, we propose a two-stage attentive network (TSAN) for accurate SISR in a coarse-to-fine manner. Specifically, we design a novel multi-context attentive block (MCAB) to make the network focus on more informative contextual features. Moreover, we present an essential refined attention block (RAB) which could explore useful cues in HR space for reconstructing fine-detailed HR image. Extensive evaluations on four benchmark datasets demonstrate the efficacy of our proposed TSAN in terms of quantitative metrics and visual effects. Code is available at https://github.com/Jee-King/TSAN .

The brain-inspired Spiking Neural Networks (SNNs) work in an event-driven manner and have an implicit recurrence in neuronal membrane potential to memorize information over time, which are inherently suitable to handle temporal event-based streams. Despite their temporal nature and recent approaches advancements, these methods have predominantly been assessed on event-based classification tasks. In this paper, we explore the utility of SNNs for event-based tracking tasks. Specifically, we propose a brain-inspired adaptive Leaky Integrate-and-Fire neuron (BA-LIF) that can adaptively adjust the membrane time constant according to the inputs, thereby accelerating the leakage of meaningless noise features and reducing the decay of valuable information. SNNs composed of our proposed BA-LIF neurons can achieve high performance without a careful and time-consuming trial-by-error initialization on the membrane time constant. The adaptive capability of our network is further improved by introducing an extra temporal feature aggregator (TFA) that assigns attention weights over the temporal dimension. Extensive experiments on various event-based tracking datasets validate the effectiveness of our proposed method. We further validate the generalization capability of our method by applying it to other event-classification tasks.

Polarization imaging is extensively employed in underwater image restoration due to its effectiveness in removing backscattered light. However, existing polarization imaging methods generally assume the degree of polarization (DoP) of the backscattering is spatially constant and estimate it from the background region, limiting their practical applications. To address these challenges, we propose an underwater image restoration method based on a polarization imaging optimization model (PIOM). First, we develop a novel polarization image formation model by fusing the DoP and angle of polarization (AoP) of backscattered light. Second, we introduce an adaptive particle swarm local optimization (APSLO) method based on the PIOM. This method decomposes the image into small blocks and employs an objective optimization function to estimate the local optimal fusion parameters. Additionally, we propose a robust polynomial spatial fitting method to reduce block artifacts and noise disturbances, achieving globally optimal fusion parameters. Finally, we fully consider the advantages of gamma correction, and propose an adaptive contrast enhancement method to balance brightness and contrast. Experimental results show that our PIOM effectively removes backscattering while preserving finer details, colors, and contours. The code and datasets will be available at https://github.com/liyafengLYF/UIRPIOM.

Existing underwater image enhancement (UIE) methods typically prioritize improving image quality at the expense of algorithmic efficiency. In this paper, we propose a fusion-based, channel-wise isotropic convergent UIE method designed for real-time performance. The proposed approach comprises three key modules: (i) a non-linear transformation module that corrects color casts and aligns the pixel distribution with the gray-world assumption (GWA); (ii) a channel-wise isotropic convergence scheme that reduces intensity distribution disparities across channels, promoting balanced convergence; and (iii) a patch-based enhancement strategy that divides the image into smaller patches to better capture local features and improve adaptability to non-uniform degradation. Moreover, certain critical steps in our method are optimized to achieve O(1) time complexity, allowing it to meet real-time requirements. Extensive experiments validate the effectiveness of each module in the proposed method, showcasing its superiority when compared to the existing state-of-the-art (SOTA) approaches. Code has been released at https://github.com/JohnChenS/FCICE_UnderwaterImageEnhancement.