Super-resolution reconstruction technology is a crucial approach to enhance the quality of remote sensing optical images. Currently, the mainstream reconstruction methods leverage Convolutional Neural Networks (CNN). However, they overlook the global information of the images, thereby impacting the reconstruction effectiveness. Methods based on Transformer networks have demonstrated the capability to improve reconstruction quality, but the high model complexity renders them unsuitable for remote sensing devices. To enhance reconstruction performance while maintaining the model lightweight, a distillation Transform-CNN Network (DTCNet) is proposed in this paper. The strategy employs the Transformer network as a teacher network, guiding its long-range features into a compact CNN, achieving distillation across networks. Simultaneously, to rectify misinformation in the teacher network, prior information is introduced to ensure accurate information transfer. Concerning the student network, a novel upsampling approach is devised, utilizing inherent information in downsampled feature maps for padding, thereby avoiding the introduction of zero-information feature points in the traditional deconvolution process. Experimental evaluations conducted on multiple publicly available remote sensing image datasets demonstrate that the proposed method, while maintaining a smaller parameter count, achieves outstanding reconstruction quality for remote sensing images, surpassing existing approaches.
Underwater object detection plays a significant role in fisheries resource assessment and ecological environment protection. However, traditional underwater object detection methods struggle to achieve accurate detection in complex underwater environments with limited computational resources. This paper proposes a lightweight underwater object detection network called LightFusionNet-YOLO (LFN-YOLO). First, we introduce the reparameterization technique RepGhost to reduce the number of parameters while enhancing training and inference efficiency. This approach effectively minimizes precision loss even with a lightweight backbone network. Then, we replaced the standard depthwise convolution in the feature extraction network with SPD-Conv, which includes an additional pooling layer to mitigate detail loss. This modification effectively enhances the detection performance for small objects. Furthermore, We employed the Generalized Feature Pyramid Network (GFPN) for feature fusion in the network's neck, enhancing the network's adaptability to features of varying scales. Finally, we design a new detection head, CLLAHead, which reduces computational costs and strengthens the robustness of the model through cross-layer local attention. At the same time, the DFL loss function is introduced to reduce regression and classification errors. Experiments conducted on public datasets, including URPC, Brackish, and TrashCan, showed that the mAP@0.5 reached 74.1%, 97.5%, and 66.2%, respectively, with parameter sizes and computational complexities of 2.7M and 7.2 GFLOPs, and the model size is only 5.9 Mb. Compared to mainstream vision models, our model demonstrates superior performance. Additionally, deployment on the NVIDIA Jetson AGX Orin edge computing device confirms its high real-time performance and suitability for underwater applications, further showcasing the exceptional capabilities of LFN-YOLO.
5 July 2023 in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Remarkable effectiveness has been demonstrated by deep neural networks in the despeckling task for Synthetic Aperture Radar (SAR) images. However, blurring and loss of fine details can result from many despeckling models due to up-sampling and mean square error (MSE) loss. Additionally, existing degradation models and prior information are ignored by existing despeckling models, which directly learn the mapping from degraded to clear images. To address these issues, an optimization algorithm for the SAR despeckling task based on the integral-Newton method is proposed in this article. Then, a prior-driven despeckling network is proposed, which can automatically capture the implicit priors in SAR images to replace traditional manually-made priors. Furthermore, to make the network focus more on learning the structural prior information of images, a structure-preserving loss function based on MSE and the Canny edge detection operator is designed, which improves the detail of the network retention ability and speeds up convergence. Outstanding results on both simulated datasets and real SAR images are achieved by the proposed method, as shown by a large number of experimental results. Moreover, significant advantages of the proposed method both visually and quantitatively are revealed by comparison with classical and state-of-the-art despeckling algorithms.
The aim of infrared (IR) and visible image fusion is to generate a more informative image for human observation or some other computer vision tasks. The activity-level measurement and weight assignment are two key parts in image fusion. In this paper, we propose a novel IR and visible fusion method based on the principal component analysis network (PCANet) and an image pyramid. Firstly, we use the lightweight deep learning network, a PCANet, to obtain the activity-level measurement and weight assignment of IR and visible images. The activity-level measurement obtained by the PCANet has a stronger representation ability for focusing on IR target perception and visible detail description. Secondly, the weights and the source images are decomposed into multiple scales by the image pyramid, and the weighted-average fusion rule is applied at each scale. Finally, the fused image is obtained by reconstruction. The effectiveness of the proposed algorithm was verified by two datasets with more than eighty pairs of test images in total. Compared with nineteen representative methods, the experimental results demonstrate that the proposed method can achieve the state-of-the-art results in both visual quality and objective evaluation metrics.