Real-time Semantic Segmentation Based on Multi-scale Feature Map Joint Pyramid Upsamping

Semantic segmentation of high-resolution optical remote sensing images is an important but challenging task. To solve the problem that many semantic segmentation networks fail to efficiently utilize global and local context information to improve the segmentation performance, this paper proposes a semantic segmentation network based on sparse self-attention (SDANet) to model the global context dependencies. Specifically, the feature maps are first divided into four regions in spatial and channel dimensions, respectively, and the divided feature maps are rearranged to form new regions. Second, the position and channel self-attention operations are performed on the rearranged regions. Third, the feature maps are restored to the original combination and the position together with channel self-attention operations are performed again to obtain the output feature maps. Finally, semantic segmentation is completed based on the output feature maps. Extensive experiments conducted on the ISPRS Vaihingen dataset demonstrate that the proposed method is superior to self-attention-based DANet, CCNet, and other general semantic segmentation networks, such as FCN, Deeplabv3+, HRNet, etc.

A Unified Architecture of Semantic Segmentation and Hierarchical Generative Adversarial Networks for Expression Manipulation

Abstract. Semantic instance segmentation from scenes, serving as a crucial role for 3D modelling and scene understanding. Conducting semantic segmentation before grouping instances is adopted by the existing state-of-the-art methods. However, without additional refinement, semantic errors will fully propagate into the grouping stage, resulting in low overlap with the ground truth instance. Furthermore, the proposed methods focused on indoor level scenes, which are limited when directly applied to large-scale outdoor Airborne Laser Scanning (ALS) point clouds. Numerous instances, significant object density and scale variations make ALS point clouds distinct from indoor data. In order to address the problems, we proposed a geometric characterization-aware semantic instance segmentation network, which utilized both semantic and objectness score to select potential points for grouping. And in point cloud feature learning stage, hand-craft geometry features are taken as input for geometric characterization awareness. Moreover, to address errors propagated from previous modules after grouping, we have additionally designed a per-instance refinement module. To assess semantic instance segmentation, we conducted experiments on an open-source dataset. Additionally, we performed semantic segmentation experiments to evaluate the performance of our proposed point cloud feature learning method.

Semantic segmentation has been proposed as a tool to accelerate the processing of natural history collection images. However, developing a flexible and resilient segmentation network requires an approach for adaptation which allows processing different datasets with minimal training and validation. This paper presents a cross-validation approach designed to determine whether a semantic segmentation network possesses the flexibility required for application across different collections and institutions. Consequently, the specific objectives of cross-validating the semantic segmentation network are to (a) evaluate the effectiveness of the network for segmenting image sets derived from collections different from the one in which the network was initially trained on; and (b) test the adaptability of the segmentation network for use in other types of collections. The resilience to data variations from different institutions and the portability of the network across different types of collections are required to confirm its general applicability. The proposed validation method is tested on the Natural History Museum semantic segmentation network, designed to process entomological microscope slides. The proposed semantic segmentation network is evaluated through a series of cross-validation experiments designed to test using data from two types of collections: microscope slides (from three institutions) and herbarium sheets (from seven institutions). The main contribution of this work is the method, software and ground truth sets created for this cross-validation as they can be reused in testing similar segmentation proposals in the context of digitization of natural history collections. The cross-validation of segmentation methods should be a required step in the integration of such methods into image processing workflows for natural history collections.

In view of the insufficient illumination of low-light images in semantic segmentation, there are phenomena such as low image brightness, contrast, and signal-to-noise ratio, which makes semantic segmentation of low-light images more difficult. A low-light image semantic segmentation method based on vector symbolic architectures domain adaptation network is proposed. The method first integrates the image translation network based on vector symbolic architectures and the domain adaptive semantic segmentation network. The image translation network translates normal illumination images into low-light images, reducing style differences between domains and improving the segmentation accuracy of low-light images. Then, a layered feature mapping (LFM) module is proposed in the image translation network. The LFM module can better map the multi-layer feature vectors of the semantic segmentation network encoder to the VSA space, making the translated image more similar to the low-light image, thereby improving the segmentation accuracy of the segmentation network. Finally, a cross domain rare class mixing (CDRCM) method is proposed in the domain adaptive semantic segmentation network. CDRCM obtains rare classes in the low-light domain based on the pseudo- label distribution of low-light images during domain adaptation, and biases towards these rare classes during cross-domain mixing, thereby improving the segmentation accuracy of rare classes in the low-light domain. The experimental results on Cityscapes→Dark Zurich and Cityscapes→ACDC-night indicated that the proposed method in the paper achieved improvements of 8.2 percentage points and 7.2 percentage points, respectively, in mean intersection-over-union compared to the baseline DAFormer, the experimental results show the effectiveness of the method.

Semantic segmentation plays an increasingly important role in the field of computer vision. The current semantic segmentation algorithms are mainly based on full convolutional network downsampling for feature extraction, however, the reduction of image resolution due to downsampling will inevitably lead to the loss of image information and the process is irreversible. Although features can be reused to compensate for the loss, the problem of lost pixel correlation and inaccurate segmentation results still occur. In order to solve these problems, the attention mechanism and the generative adversarial network are fused into the semantic segmentation network, and a semantic segmentation network is proposed. The attention mechanism is added to the generator and discriminator modules and trained successively, then the generator module with rich information and global information is extracted, and its output is fused with the feature graph sampled above, in order to reduce the loss of local information and complete the task of image segmentation, an interpolation method based on image edge is introduced to sample the image, which improves the bilinear interpolation edge blur. Experiments on Cityscapes dataset show that the proposed network model is effective and reliable.

In remote-sensing image (RSI) semantic segmentation, the dependence on large-scale and pixel-level annotated data has been a critical factor restricting its development. In this letter, we propose an unsupervised semantic segmentation network embedded with geometry consistency (UGCNet) for RSIs, which imports the adversarial-generative learning strategy into a semantic segmentation network. The proposed UGCNet can be trained on a source-domain dataset and achieve accurate segmentation results on a different target-domain dataset. Furthermore, for refining the remote-sensing target geometric representation such as densely distributed buildings, we propose a geometry-consistency (GC) constraint that can be embedded in both image-domain adaptation process and semantic segmentation network. Therefore, our model could achieve cross-domain semantic segmentation with target geometric property preservation. The experimental results on Massachusetts and Inria buildings datasets prove that the proposed unsupervised UGCNet could achieve a very comparable segmentation accuracy with the fully supervised model, which validates the effectiveness of the proposed method.

Linear feature extraction is crucial for special objects in semantic segmentation networks, such as slot marking and lanes. The objects with linear characteristics have global contextual information dependency. It is very difficult to capture the complete information of these objects in semantic segmentation tasks. To improve the linear feature extraction ability of the semantic segmentation network, we propose introducing the dilated convolution with vertical and horizontal kernels (DVH) into the task of feature extraction in semantic segmentation networks. Meanwhile, we figure out the outcome if we put the different vertical and horizontal kernels on different places in the semantic segmentation networks. Our networks are trained on the basis of the SS dataset, the TuSimple lane dataset and the Massachusetts Roads dataset. These datasets consist of slot marking, lanes, and road images. The research results show that our method improves the accuracy of the slot marking segmentation of the SS dataset by 2%. Compared with other state-of-the-art methods, our UnetDVH-Linear (v1) obtains better accuracy on the TuSimple Benchmark Lane Detection Challenge with a value of 97.53%. To prove the generalization of our models, road segmentation experiments were performed on aerial images. Without data argumentation, the segmentation accuracy of our model on the Massachusetts roads dataset is 95.3%. Moreover, our models perform better than other models when training with the same loss function and experimental settings. The experiment result shows that the dilated convolution with vertical and horizontal kernels will enhance the neural network on linear feature extraction.

Semantic segmentation is a fundamental task in remote sensing image processing. It provides pixel-level classification, which is important for many applications, such as building extraction and land use mapping. The development of convolutional neural network has considerably improved the performance of semantic segmentation. Most semantic segmentation networks are the encoder–decoder structure. Bilinear interpolation is an ordinary upsampling method in the decoder, but bilinear interpolation only considers its own features and inserts three times its own features. This over-simple and data-independent bilinear upsampling may lead to suboptimal results. In this work, we propose an upsampling method based on local relations to replace bilinear interpolation. Upsampling is performed by correlating the local relationship of feature maps of adjacent stages, which can better integrate local and global information. We also design a fusion module based on local similarity. Our proposed method with ResNet101 as the backbone of the segmentation network can improve the average <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$F_{1}$ </tex-math></inline-formula> score and overall accuracy of the Vaihingen data set by 2.69% and 1.31%, respectively. Our proposed method also has fewer parameters and less inference time.

As one of the most important components of urban space, an outdated inventory of road-side trees may misguide managers in the assessment and upgrade of urban environments, potentially affecting urban road quality. Therefore, automatic and accurate instance segmentation of road-side trees from urban point clouds is an important task in urban ecology research. However, previous works show under- or over-segmentation effects for road-side trees due to overlapping, irregular shapes and incompleteness. In this paper, a deep learning framework that combines semantic and instance segmentation is proposed to extract single road-side trees from vehicle-mounted mobile laser scanning (MLS) point clouds. In the semantic segmentation stage, the ground points are filtered to reduce the processing time. Subsequently, a graph-based semantic segmentation network is developed to segment road-side tree points from the raw MLS point clouds. For the individual tree segmentation stage, a novel joint instance and semantic segmentation network is adopted to detect instance-level roadside trees. Two complex Chinese urban point cloud scenes are used to evaluate the individual urban tree segmentation performance of the proposed method. The proposed method accurately extract approximately 90% of the road-side trees and achieve better segmentation results than existing published methods in both two urban MLS point clouds. Living Vegetation Volume (LVV) calculation can benefit from individual tree segmentation. The proposed method provides a promising solution for ecological construction based on the LVV calculation of urban roads.

The semantic segmentation of remote sensing images faces two major challenges: high inter-class similarity and interference from ubiquitous shadows. In order to address these issues, we develop a novel edge loss reinforced semantic segmentation network (ERN) that leverages the spatial boundary context to reduce the semantic ambiguity. The main contributions of this paper are as follows: (1) we propose a novel end-to-end semantic segmentation network for remote sensing, which involves multiple weighted edge supervisions to retain spatial boundary information; (2) the main representations of the network are shared between the edge loss reinforced structures and semantic segmentation, which means that the ERN simultaneously achieves semantic segmentation and edge detection without significantly increasing the model complexity; and (3) we explore and discuss different ERN schemes to guide the design of future networks. Extensive experimental results on two remote sensing datasets demonstrate the effectiveness of our approach both in quantitative and qualitative evaluation. Specifically, the semantic segmentation performance in shadow-affected regions is significantly improved.

&lt;span lang="EN-US"&gt;Intelligent transportation systems (ITS) are among the most focused research in this century. Actually, autonomous driving provides very advanced tasks in terms of road safety monitoring which include identifying dangers on the road and protecting pedestrians. In the last few years, deep learning (DL) approaches and especially convolutional neural networks (CNNs) have been extensively used to solve ITS problems such as traffic scene semantic segmentation and traffic signs classification. Semantic segmentation is an important task that has been addressed in computer vision (CV). Indeed, traffic scene semantic segmentation using CNNs requires high precision with few computational resources to perceive and segment the scene in real-time. However, we often find related work focusing only on one aspect, the precision, or the number of computational parameters. In this regard, we propose RBANet, a robust and lightweight CNN which uses a new proposed balanced attention module, and a new proposed residual module. Afterward, we have simulated our proposed RBANet using three loss functions to get the best combination using only 0.74M parameters. The RBANet has been evaluated on CamVid, the most used dataset in semantic segmentation, and it has performed well in terms of parameters’ requirements and precision compared to related work.&lt;/span&gt;

Point cloud segmentation is essential for scene understanding, which provides advanced information for many applications, such as autonomous driving, robots, and virtual reality. To improve the accuracy and robustness of point cloud segmentation, many researchers have attempted to fuze camera images to complement the color and texture information. The common fusion strategy is the combination of convolutional operations with concatenation, element-wise addition or element-wise multiplication. However, conventional convolutional operators tend to confine the fusion of modal features within their receptive fields, which can be incomplete and limited. In addition, the inability of encoder–decoder segmentation networks to explicitly perceive segmentation boundary information results in semantic ambiguity and classification errors at object edges. These errors are further amplified in point cloud segmentation tasks, significantly affecting the accuracy of point cloud segmentation. To address the above issues, we propose a novel self-attention multi-modal fusion semantic segmentation network for point cloud semantic segmentation. Firstly, to effectively fuze different modal features, we propose a self-cross fusion module (SCF), which models long-range modality dependencies and transfers complementary image information to the point cloud to fully leverage the modality-specific advantages. Secondly, we design the salience refinement module (SR), which calculates the importance of channels in the feature maps and global descriptors to enhance the representation capability of salient modal features. Finally, we propose the local-aware anisotropy loss measure the element-level importance in the data and explicitly provide boundary information for the model, which alleviates the inherent semantic ambiguity problem in segmentation networks. Extensive experiments on two benchmark datasets demonstrate that our proposed method surpasses current state-of-the-art methods.

Road conditions in real-world driving are highly complex and subject to frequent changes. Traditional perception strategies often struggle to simultaneously achieve accurate road type classification and real-time estimation of roughness grade, especially under aging infrastructure, where two key challenges arise: the non-uniqueness of the ‘road types and roughness grades’ mapping, and the difficulty in accurately estimating impulsive feature parameters. To address these issues, this paper proposes a multimodal fusion road perception strategy for intelligent suspension systems, aiming to enhance perception accuracy and robustness by integrating visual imagery and dynamic response data. First, a data acquisition platform is developed to collect typical datasets covering both random and impulsive road surfaces. To resolve the non-uniqueness of the ‘road types and roughness grades’ mapping, a convolutional block attention module deeplabV3(CBAM-DeepLabV3) semantic segmentation network is used to extract visual road type features, and a random forest extreme gradient boosting (RF-XGBoost) model is employed to estimate road roughness grades. This fusion approach reveals the inherent ambiguity in the mapping between road types and roughness levels. A dynamic mapping inference mechanism is then constructed to enable adaptive updates of the mapping rules. To address the difficulty in estimating impulsive feature parameters, a novel method combining inverse perspective transformation with reinforcement learning is proposed. This approach enables multidimensional measurement of impulsive features, including longitudinal distance, width, and vertical height, significantly improving both parameter recognition accuracy and real-time performance. The proposed method is validated using a co-simulation platform based on Prescan, Carsim and Simulink. Test results show that the method achieves high recognition accuracy and strong generalization capability in road perception tasks, providing robust prior perception support for intelligent suspension control systems.

The lane line detection methods based on semantic segmentation networks have achieved remarkable results in recent years. However, the semantic segmentation networks are aimed at the pixel level. These methods have a large amount of computation, which can reduce the real-time performance. To reduce the calculation, we propose a Light-weight Lane line detection Network (LLNet). A new sub-layer is established. We also adopt a jumping structure between two sub-layers to enhance the supervisory role of ground truth. Furthermore, we adopt two branches, including instance segmentation and embeddable branch. The combination of two branches can filter out the wrongly detected pixels and further improve the accuracy of detection. Experimental results in the Tusimple dataset show that the detection accuracy of the proposed network is comparable with LaneNet. Meanwhile, it has good real-time performance, and the processing time of a single image is 10.285 ms, which is about one-half of LaneNet.