Traffic sign detection algorithm based on improved YOLOv5

Traffic sign recognition is a important component of environmental perception technology, with significant potential in the field of autonomous vehicles. Traditional recognition methods are susceptible to factors such as lighting conditions, extreme weather, and distance, leading to mismatches. To tackle this problem, this study proposed an improved YOLOv7-based algorithm for traffic sign recognition, aimed at enhancing the accuracy of small traffic sign recognition. Firstly, an ACmix attention mechanism module is inserted after the SPPCSPC layer in the backbone of the YOLOv7 network to enhance feature extraction capability and adaptability to complex scenarios. Secondly, the SIoU loss function is employed to replace the original YOLOv7 bounding box loss function, thus improving the precision of bounding box regression and localization. Extensive experiments are conducted to validate the effectiveness of the proposed algorithm. The improved algorithm is tested and evaluated using the TT100K dataset, achieving a recognition accuracy of 94.23%, a recall rate of 78.1%, [email protected] of 86.5%, and [email protected]:0.95 of 65.6%, surpassing the original YOLOv7 network. Moreover, the frame rate remains stable at 82 frames per second. The evaluations on traffic sign datasets demonstrate the accuracy and effectiveness of the proposed method.

A multi-scale semantic feature fusion method for remote sensing crop classification

Object detection (OD) in unmanned aerial vehicle (UAV) images faces many challenges, with diverse-scale objects and small objects being particularly prominent issues. To alleviate these challenges, we propose a novel multiscale feature learning and feature fusion network under the guidance of deformable convolution. First, a deformable convolution-guided feature learning (DCGFL) block is designed in the backbone to extract more effective multiscale features. The DCGFL block leverages the adaptability of deformable convolution to the shapes and scales of objects, akin to spatial attention. Moreover, it also employs channel attention to identify important feature maps. Hence, the proposed backbone possesses the functionality of spatial attention and channel attention. Second, in the neck, we devise a simple generalized feature pyramid network (SimpleGFPN) with several deformable convolution-guided feature fusion (DCGFF) blocks to fuse multiscale features. The proposed neck has cross-layer and cross-scale pathways, facilitating effective information exchange and fusion between shallow spatial and deep semantic features. Third, the SIoU loss is used to better model the bounding box regression loss. Finally, experimental results on the VisDrone2021 and UAVDT datasets show that the proposed method outperforms the compared OD methods. In terms of mean average precision, we obtain 37.8% on VisDrone2021 and 18.5% on UAVDT.

The performance of underwater target detection algorithms is affected by poor imaging quality in underwater environments. Due to the arithmetic power limitation of underwater devices, existing deep learning networks are unable to provide efficient detection processes with high detection accuracy. Lightweight CNN models have been actively applied for underwater environment detection, yet their lite feature fusion networks cannot provide effective fusion effects and reduce the detection accuracy. In this paper, a lightweight algorithm based on multi-scale feature fusion was proposed, with the model parameters greatly reduced, improving the target detection accuracy. The forward propagation memory overhead is reduced by using multi-scale shared convolutional kernels and pooling operations to co-construct the query matrix in the Tansformer encoding stage. Then, the feature fusion path is optimized in order to enhance the connection of multi-scale features. A multiscale feature adaptive fusion strategy is used to enhance the detection performance and reduce the dependence on the complex feature extraction network. The feature extraction network is also reparameterized to simplify the operation. Using the UPRC offshore dataset for validation, the study results have demonstrated that the statistical mAP metrics validate the detection accuracy. Compared with SSD, RetinaNet and YOLOv5-s improved by 13%, 8.6%, and 0.8%, while the number of parameters decreased by 76.09%, 89.74%, and 87.67%. In addition, compared with the YOLOv5-lite model algorithm with the same parameter volume, the mAP is improved by 3.8%, which verifies the accuracy and efficiency of the algorithm in this paper.

With the continuous development of driving assistance system and automatic driving technology in recent years, the requirements for traffic sign recognition technology are becoming higher and higher. Although the current mainstream target detection technology has been guaranteed in real-time and accuracy, due to the complexity of traffic signs and the fact that most traffic signs in the actual scene are small and dense, the identification accuracy of small target traffic signs is low. Based on the above situation, an improved YOLOv5 traffic sign recognition algorithm is proposed. We add CBAM attention mechanism to the model to improve the feature extraction ability of the target object. The structure based on the feature pyramid is improved to strengthen the features of small targets. The upsampling algorithm is replaced to save computing power. The overall detection and recognition ability of the model is improved. The loss function is improved to DIoU loss function, which enhances the robustness of the model.

IntroductionThe cigar leaves moisture content (CLMC) is a critical parameter for controlling curing barn conditions. Along with the continuous advancement of deep learning (DL) technologies, convolutional neural networks (CNN) have provided a way of thinking for the non-destructive estimation of CLMC during the air-curing process. Nevertheless, relying merely on single-perspective imaging makes it difficult to comprehensively capture the complementary morphological features of the front and back sides of cigar leaves during the air-curing process.MethodsThis study constructed a dual-view image dataset covering the air-curing process, and proposes a regression framework named CADFFNet (channel attention weight-based dual-branch feature fusion network) for the non-destructive estimation of CLMC during the curing process based on dual-view RGB images. Firstly, the model utilizes two independent and parallel ResNet as its backbone structure to capture the heterogeneous features of dual-view images. Secondly, the Dual Efficient Channel Attention (DECA) module is introduced to dynamically adjust the channel attention weights of the features, thereby facilitating interaction between the two branches. Lastly, a Multi-scale convolutional feature fusion (MSCFF) module is designed for the deep fusion of features from the front and back images to aggregate multi-scale features for robust regression.ResultsOn five-fold cross-validation, CADFFNet attains R2 of 0.974±0.007 and mean absolute error (MAE) of 3.80±0.37%. On an independent cross-region, cross-variety testing set, it maintains strong generalization (R2=0.899, MAE=5.82%), compared with the classic CNN models ResNet18, GoogLeNet, VGG19Net, DenseNet121, and MobileNetV2, its R2 value has increased by 0.047, 0.041, 0.055, 0.098, and 0.090 respectively.DiscussionGenerally, the proposed CADFFNet offers an efficient and convenient method for non-destructive detection of CLMC, providing a theoretical basis for automating the air-curing process. It also provides a new perspective for moisture content prediction during the drying process of other crops, such as tea, asparagus, and mushrooms.

The fully convolutional networks (FCNs) have been widely applied in numerous medical image segmentation tasks. However, tissue regions usually have large variations of shape and scale, so the ability of neural networks to learn multi-scale features is important to the segmentation performance. In this paper, we improve the network for multi-scale feature fusion, in the medical image segmentation by introducing two feature fusion modules: i) global attention multi-scale feature fusion module (GMF); ii) local dense multi-scale feature fusion module (LMF). GMF aims to use global context information to guide the recalibration of low-level features from both spatial and channel aspects, so as to enhance the utilization of effective multi-scale features and suppress the noise of low-level features. LMF adopts bottom-up top-down structure to capture context information, to generate semantic features, and to fuse feature information at different scales. LMF can integrate local dense multi-scale context features layer by layer in the network, thus improving the ability of network to encode interdependent relationships among boundary pixels. Based on the above two modules, we propose a novel medical image segmentation framework (GLF-Net). We evaluated the proposed network and modules on challenging brain tumor segmentation and pancreas segmentation datasets, and very competitive performance has been achieved.

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To address the frequent missed detections and suboptimal accuracy in electronic component circuit board inspection, a target detection algorithm for electronic components, EM-YOLO, is designed with YOLOv11 as the core framework. The overall design employs a three-level optimization strategy: First, in the backbone network part, an efficient feature extraction module C3k2_EMA is designed. By incorporating the Efficient Multi-scale Attention (EMA) mechanism, it enhances the network’s feature representation capability for tiny components. Second, in the neck network part, the BiSPD-FPN structure is proposed, which adds a high-resolution feature map at the P2 level. By combining the Bidirectional Feature Pyramid Network (BiFPN) with Spatial Pyramid Depthwise Convolution (SPDConv), it optimizes the multi-scale feature fusion capability and reduces detail loss during the downsampling process. Finally, in the detection head part, the Focal-DIoU loss function is introduced to optimize the bounding box regression process and improve the localization accuracy of densely arranged components. Experimental results show that, on the self-made dataset and the public dataset PCB Electronic Components Dataset, the detection accuracy (mAP@0.5) of the improved algorithm has increased by 0.5% and 3.9% respectively compared with the benchmark algorithm, while the false negative rate (FNR) has decreased by 1.3% and 4% respectively, both outperforming mainstream algorithms. Therefore, the algorithm in this paper exhibits good detection accuracy, and the problem of missed detections occurring in the detection process has also been effectively alleviated. It possesses good generalization ability and provides an effective detection scheme for component detection.

ObjectiveIn computer-aided medical diagnosis, precise skin lesion segmentation is crucial for the early detection and treatment of skin cancer. However, challenges such as unclear lesion boundaries, low contrast, and varying lesion shapes make accurate segmentation a difficult task. To address these challenges, we propose DMFF-Net, a multi-scale, multi-attention feature fusion network based on DeepLabV3, designed to improve the accuracy of skin lesion segmentation.MethodsDMFF-Net integrates several advanced modules to enhance segmentation performance. The network incorporates a Global Grid Coordinate Attention Module (GGCAM), which effectively fuses spatial and channel features to capture the complex relationships between local and global information. Additionally, a Multi-Scale Depthwise Separable Dilated Convolution (MDSDC) module is employed to strengthen multi-scale feature extraction, thereby preventing resolution degradation during convolution. A Mid-High Level Feature Fusion (MHLFF) module is also introduced to refine critical feature representations and suppress irrelevant information, thereby improving segmentation accuracy.ResultsThe proposed network was evaluated on four publicly available datasets: ISIC 2016, ISIC 2017, ISIC 2018, and PH2. The results show that DMFF-Net significantly outperforms existing advanced methods. Specifically, it achieves MIoU values of 89.31%, 91.47%, and 86.93% on the ISIC 2016, ISIC 2017, and ISIC 2018 datasets, respectively. Furthermore, the network achieves accuracy values of 95.62%, 97.33%, and 94.78%, and F1 scores of 96.93%, 94.91%, and 93.61%, respectively, demonstrating its robustness and effectiveness in skin lesion segmentation.ConclusionThe DMFF-Net model, with its multi-scale feature fusion and attention mechanisms, substantially improves skin lesion segmentation by preserving crucial spatial details and improving feature representation. Its superior performance on multiple datasets highlights its potential as a powerful tool for skin lesion diagnosis and provides an important reference for future advancements in medical image segmentation.

Image dehazing is critical for visual enhancement and a wide range of computer vision applications. Despite significant advancements, challenges remain in preserving fine details and adapting to diverse, non-uniformly degraded scenes. To address these issues, we propose a novel image dehazing method that introduces a contrastive learning framework, enhanced by the InfoNCE loss, to improve model robustness. In this framework, hazy images are treated as negative samples and their clear counterparts as positive samples. By optimizing the InfoNCE loss, the model is trained to maximize the similarity between positive pairs and minimize that between negative pairs, thereby improving its ability to distinguish haze artifacts from intrinsic scene features and better preserving the structural integrity of images. In addition to contrastive learning, our method integrates a multi-scale dynamic feature fusion with a hybrid attention mechanism. Specifically, we introduce dynamically adjustable frequency band filters and refine the hybrid attention module to more effectively capture fine-grained, cross-scale image details. Extensive experiments on the RESIDE-6K and RS-Haze datasets demonstrate that our approach outperforms most existing methods, offering a promising solution for practical image dehazing applications.

To address the problem of inaccurate representation, inadequate fusion and unsmooth results in video-based single person three-dimensional human pose estimation, a multi-scale spatial-temporal feature fusion method is proposed. Firstly, the joint, limb and upper/lower body tokens were defined in spatial domain to represent the spatial multi-scale features of human body using positional embeddings. Secondly, the spatial multi-scale feature fusion module was constructed based on self-attention mechanism and multilayer perceptron to fuse joint, limb and upper/lower body features, obtaining initial pose feature sequence. Lastly, the temporal multi-scale encoding was established for temporal feature fusion to acquire final pose feature sequence, and optimize the generation of refined three-dimensional human pose through temporal decoding. Experimental results on Human3.6M dataset show that the mean per joint position error and joint velocity errors are 33.6 and 2.4 respectively, which reduce by 2.3% and 4.0%. The proposed method can improve three-dimensional human pose estimation accuracy and generate precise and smooth results while reducing computational cost. Furthermore, experimental results on HumanEva-I dataset show that the proposed method also has a certain degree of generalization ability.

The classification of high-resolution (HR) synthetic aperture radar (SAR) images is of great importance for SAR scene interpretation and application. However, the presence of intricate spatial structural patterns and complex statistical nature makes SAR image classification a challenging task, especially in the case of limited labeled SAR data. This paper proposes a novel HR SAR image classification method, using a multi-scale deep feature fusion network and covariance pooling manifold network (MFFN-CPMN). MFFN-CPMN combines the advantages of local spatial features and global statistical properties and considers the multi-feature information fusion of SAR images in representation learning. First, we propose a Gabor-filtering-based multi-scale feature fusion network (MFFN) to capture the spatial pattern and get the discriminative features of SAR images. The MFFN belongs to a deep convolutional neural network (CNN). To make full use of a large amount of unlabeled data, the weights of each layer of MFFN are optimized by unsupervised denoising dual-sparse encoder. Moreover, the feature fusion strategy in MFFN can effectively exploit the complementary information between different levels and different scales. Second, we utilize a covariance pooling manifold network to extract further the global second-order statistics of SAR images over the fusional feature maps. Finally, the obtained covariance descriptor is more distinct for various land covers. Experimental results on four HR SAR images demonstrate the effectiveness of the proposed method and achieve promising results over other related algorithms.

Unmanned aerial vehicles (UAVs) have been widely used in post-disaster search and rescue operations, object tracking, and other tasks. Therefore, the autonomous perception of UAVs based on computer vision has become a research hotspot in recent years. However, UAV images include dense objects, small objects, and arbitrary object directions, which bring about significant challenges to existing object detection methods. To alleviate these issues, we propose a global-local feature enhanced network (GLF-Net). Considering the difficulty of processing UAV images with complex scenes and dense objects, we designed a backbone based on an involution and self-attention that can extract effective features from complex objects. A multiscale feature fusion module is also proposed to address the presence of numerous small objects in UAV images through multiscale object detection and feature fusion. To accurately detect rotated objects, a rotated regional proposal network was designed based on the midpoint offset representation, which can apply a rotated box to determine the real direction and contour of an object. GLF-Net achieves a state-of-the-art detection accuracy (86.52% mAP) on our created RO-UAV dataset, while achieving 96.95% and 97% mAP on the public datasets HRSC2016 and UCAS-AOU, respectively. The experimental results demonstrate that our method achieves a high detection accuracy and generalization, which can meet the practical requirements of UAVs under various complex scenarios.

Aiming at the problems of leakage, misdetection and low detection efficiency of transmission line foreign object detection in railroad environment, we propose an improved railroad transmission line foreign object detection algorithm MRS-YOLO based on YOLOv11n. Firstly, a multi-scale Adaptive Kernel Depth Feature Fusion (MAKDF) module is proposed and fused with the C3k2 module to form C3k2_MAKDF, which enhances the model's feature extraction capability for foreign objects of different sizes and shapes. Secondly, a novel Re-calibration Feature Fusion Pyramid Network(RCFPN) is designed as a Neck structure to improve the feature fusion capability of the model. Then, Spatial and Channel Reconstruction Detect Head (SC_Detect) based on spatial and channel preprocessing is designed to improve the overall detection accuracy of the model. Finally, the channel pruning technique is used to reduce the redundancy of the improved model, drastically reduce Parameters and GFLOPs, and improve the detection efficiency. The experimental results show that the mAP50 and mAP50:95 of the MRS-YOLO algorithm proposed in this paper are improved to 94.8% and 86.4%, respectively, which are 0.7 and 2.3 percentage points higher compared to the baseline, while Parameters and GFLOPs are reduced by 44.2% and 17.5%, respectively. It is demonstrated that the improved algorithm can be better applied to the task of foreign object detection in railroad transmission lines.