455 research outputs found

    High-Resolution Land Use And Land Cover Mapping: Boone, North Carolina

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    Traditional Land Use and Land Cover (LULC) datasets typically occur on a coarse spatial scale. With the accessibility of more sources of higher spatial resolution imagery, the overall accuracy of these datasets can be enhanced. The increase in spatial resolution often comes at a cost to the spectral information contained within imagery. A two-step object based image analysis (OBIA) technique along with thresholding of spectral bands and a Normalized Difference Vegetation Index (NDVI) were used to create a LULC map for the Boone area in North Carolina

    Procedural Modeling and Physically Based Rendering for Synthetic Data Generation in Automotive Applications

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    We present an overview and evaluation of a new, systematic approach for generation of highly realistic, annotated synthetic data for training of deep neural networks in computer vision tasks. The main contribution is a procedural world modeling approach enabling high variability coupled with physically accurate image synthesis, and is a departure from the hand-modeled virtual worlds and approximate image synthesis methods used in real-time applications. The benefits of our approach include flexible, physically accurate and scalable image synthesis, implicit wide coverage of classes and features, and complete data introspection for annotations, which all contribute to quality and cost efficiency. To evaluate our approach and the efficacy of the resulting data, we use semantic segmentation for autonomous vehicles and robotic navigation as the main application, and we train multiple deep learning architectures using synthetic data with and without fine tuning on organic (i.e. real-world) data. The evaluation shows that our approach improves the neural network's performance and that even modest implementation efforts produce state-of-the-art results.Comment: The project web page at http://vcl.itn.liu.se/publications/2017/TKWU17/ contains a version of the paper with high-resolution images as well as additional materia

    Rain Removal in Traffic Surveillance: Does it Matter?

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    Varying weather conditions, including rainfall and snowfall, are generally regarded as a challenge for computer vision algorithms. One proposed solution to the challenges induced by rain and snowfall is to artificially remove the rain from images or video using rain removal algorithms. It is the promise of these algorithms that the rain-removed image frames will improve the performance of subsequent segmentation and tracking algorithms. However, rain removal algorithms are typically evaluated on their ability to remove synthetic rain on a small subset of images. Currently, their behavior is unknown on real-world videos when integrated with a typical computer vision pipeline. In this paper, we review the existing rain removal algorithms and propose a new dataset that consists of 22 traffic surveillance sequences under a broad variety of weather conditions that all include either rain or snowfall. We propose a new evaluation protocol that evaluates the rain removal algorithms on their ability to improve the performance of subsequent segmentation, instance segmentation, and feature tracking algorithms under rain and snow. If successful, the de-rained frames of a rain removal algorithm should improve segmentation performance and increase the number of accurately tracked features. The results show that a recent single-frame-based rain removal algorithm increases the segmentation performance by 19.7% on our proposed dataset, but it eventually decreases the feature tracking performance and showed mixed results with recent instance segmentation methods. However, the best video-based rain removal algorithm improves the feature tracking accuracy by 7.72%.Comment: Published in IEEE Transactions on Intelligent Transportation System

    Road Detection and Recognition from Monocular Images Using Neural Networks

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    Teede eristamine on oluline osa iseseisvatest navigatsioonisüsteemidest, mis aitavad robotitel ja autonoomsetel sõidukitel maapinnal liikuda. See on kasutusel erinevates seotud alamülesannetes, näiteks võimalike valiidsete liikumisteede leidmisel, takistusega kokkupõrke vältimisel ja teel asuvate objektide avastamisel.Selle töö eesmärk on uurida eksisteerivaid teede tuvastamise ja eristamise võtteid ning pakkuda välja alternatiivne lahendus selle teostamiseks.Töö jaoks loodi 5300-pildine andmestik ilma lisainfota teepiltidest. Lisaks tehti kokkuvõte juba eksisteerivatest teepiltide andmestikest. Töös pakume erinevates keskkondades asuvate teede piltide klassifitseerimiseks välja LeNet-5’l põhineva tehisnärvivõrgu. Samuti esitleme FCN-8’l põhinevat mudelit pikslipõhiseks pildituvastuseks.Road recognition is one of the important aspects in Autonomous Navigation Systems. These systems help to navigate the autonomous vehicle and robot on the ground. Further, road detection is useful in related sub-tasks such as finding valid road path where the robot/vehicle can go, for supportive driverless vehicles, preventing the collision with the obstacle, object detection on the road, and others.The goal of this thesis is to examine existing road detection and recognition techniques and propose an alternative solution for road classification and detection task.Our contribution consists of several parts. Firstly, we released the road images dataset with approximately 5,300 unlabeled road images. Secondly, we summarized the information about the existing road images datasets. Thirdly, we proposed the convolutional LeNet-5-based neural network for the road image classification for various environments. Finally, our FCN-8-based model for pixel-wise image recognition has been presented
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