objectcategorization has been an important task of computer vision research in recent years. In this paper, we propose a new approach for representing and learning 3dobject categories. First, We extract the Viewpoin...
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ISBN:
(纸本)9789897582264
objectcategorization has been an important task of computer vision research in recent years. In this paper, we propose a new approach for representing and learning 3dobject categories. First, We extract the Viewpoint Feature Histogram (VFH) descriptor from point clouds and then we learn the resulting features using deep learning architectures. We evaluate the performance of both generative anddiscriminative deep belief network architectures (GdBN/ddBN) for objectcategorization task. GdBN trains a sequence of Restricted Boltzmann Machines (RBMs) while ddBN uses a new deep architecture based on RBMs and the joint density model. Our results show the power of discriminative model for objectcategorization and outperform state-of-the-art approaches when tested on the Washington RGBddataset.
Most object classes share a considerable amount of local appearance and often only a small number of features are discriminative. The traditional approach to represent an object is based on a summarization of the loca...
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ISBN:
(纸本)9781467363563
Most object classes share a considerable amount of local appearance and often only a small number of features are discriminative. The traditional approach to represent an object is based on a summarization of the local characteristics by counting the number of feature occurrences. In this paper we propose the use of a recently developed technique for summarizations that, rather than looking into the quantity of features, encodes their quality to learn a description of an object. Our approach is based on extracting and aggregating only the essential characteristics of an object class for a task. We show how the proposed method significantly improves on previous work in 3d object categorization. We discuss the benefits of the method in other scenarios such as robot grasping. We provide extensive quantitative and qualitative experiments comparing our approach to the state of the art to justify the described approach.
In this paper, we propose a novel framework for 3dobject retrieval andcategorization. The object is modeled in terms of its subparts as an histogram of 3d visual word occurrences. We introduce an effective method fo...
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In this paper, we propose a novel framework for 3dobject retrieval andcategorization. The object is modeled in terms of its subparts as an histogram of 3d visual word occurrences. We introduce an effective method for hierarchical 3dobject segmentation driven by the minima rule that combines spectral clustering-for the selection of seed-regions-with region growing based on fast marching. descriptors attached to the regions allow the definition of the visual words. After coding of each object according to the Bag-of-Words paradigm, retrieval can be performed by matching with a suitable kernel, or categorization by learning a Support Vector Machine. Several examples on the Aim@Shape watertight dataset and on the Tosca dataset demonstrate the versatility of the proposed method in working with either 3dobjects with articulated shape changes or partially occluded or compoundobjects. Results are encouraging as shown by the comparison with other methods for each of the analyzed scenarios.
In this paper, we address the problem of 3d object categorization for point clouddata. With the availability of inexpensive scanning devices and powerful computational resources, there is a rapid growth of point clou...
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ISBN:
(纸本)9781450366151
In this paper, we address the problem of 3d object categorization for point clouddata. With the availability of inexpensive scanning devices and powerful computational resources, there is a rapid growth of point clouddata. This necessitates efficient classification techniques which form the basis for analysis and processing of 3d point clouddata. In order to address the classification problem, we propose a 3d object categorization framework for both rigid and non-rigidobjects. Initially, the proposed approach extracts the feature descriptors using improved wave kernel signature by approximating Laplace-Beltrami operator on point clouddata for non-rigidobjects. For rigidobjects, our approach uses the geometric features, namely, metric tensor and Christoffel symbols by modifying the geodesic distance computation. These feature descriptors are then represented using bag-of-features and improved Fisher vector encoding techniques. Finally, the support vector machine classifies the 3dobjects into predefined set of classes. We also provide an exhaustive performance evaluation of the proposed3d object categorization framework on state-of-the-art datasets, namely, SHREC'10, SHREC'11, SHREC'12, SHREC'15 and Princeton Shape Benchmark. The evaluation results reveal that the proposed approach outperforms the existing objectcategorization methods for both rigid and non-rigid3dobjects.
Environment understanding in real-world scenarios has gained an increased interest in research and industry. The advances in data capture and processing allow a high-detailed reconstruction from a set of multi-view im...
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Environment understanding in real-world scenarios has gained an increased interest in research and industry. The advances in data capture and processing allow a high-detailed reconstruction from a set of multi-view images by generating meshes and point clouds. Likewise, deep learning architectures along with the broad availability of image datasets bring new opportunities for the segmentation of 3d models into several classes. Among the areas that can benefit from 3d semantic segmentation is the automotive industry. However, there is a lack of labeled3d models that can be useful for training and use as ground truth in deep learning-based methods. In this work, we propose an automatic procedure for the generation and semantic segmentation of 3d cars that were obtained from the photogrammetric processing of UAV-based imagery. Therefore, sixteen car parts are identified in the point cloud. To this end, a convolutional neural network based on the U-Net architecture combined with an Inception V3 encoder was trained in a publicly available dataset of car parts. Then, the trained model is applied to the UAV-based images and these are mapped on the photogrammetric point clouds. According to the preliminary image-based segmentation, an optimization method is developed to get a full labeled point cloud, taking advantage of the geometric and spatial features of the 3d model. The results demonstrate the method's capabilities for the semantic segmentation of car models. Moreover, the proposed methodology has the potential to be extended or adapted to other applications that benefit from 3d segmented models.
In this paper, we address the problem of 3d object categorization for point clouddata. With the availability of inexpensive scanning devices and powerful computational resources, there is a rapid growth of point clou...
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ISBN:
(纸本)9781450366151
In this paper, we address the problem of 3d object categorization for point clouddata. With the availability of inexpensive scanning devices and powerful computational resources, there is a rapid growth of point clouddata. This necessitates efficient classification techniques which form the basis for analysis and processing of 3d point clouddata. In order to address the classification problem, we propose a 3d object categorization framework for both rigid and non-rigidobjects. Initially, the proposed approach extracts the feature descriptors using improved wave kernel signature by approximating Laplace-Beltrami operator on point clouddata for non-rigidobjects. For rigidobjects, our approach uses the geometric features, namely, metric tensor and Christoffel symbols by modifying the geodesic distance computation. These feature descriptors are then represented using bag-of-features and improved Fisher vector encoding techniques. Finally, the support vector machine classifies the 3dobjects into predefined set of classes. We also provide an exhaustive performance evaluation of the proposed3d object categorization framework on state-of-the-art datasets, namely, SHREC'10, SHREC'11, SHREC'12, SHREC'15 and Princeton Shape Benchmark. The evaluation results reveal that the proposed approach outperforms the existing objectcategorization methods for both rigid and non-rigid3dobjects.
This paper proposes a novel hierarchical compositional representation of 3d shape that can accommodate a large number of object categories and enables efficient learning and inference. The hierarchy starts with simple...
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ISBN:
(纸本)9781479952083
This paper proposes a novel hierarchical compositional representation of 3d shape that can accommodate a large number of object categories and enables efficient learning and inference. The hierarchy starts with simple pre-defined parts on the first layer, after which subsequent layers are learned recursively by taking the most statistically significant compositions of parts from the previous layer. Our representation is able to scale because of its very economical use of memory and because subparts of the representation are shared. We apply our representation to 3d multi-class objectcategorization. object categories are represented by histograms of compositional parts, which are then used as inputs to an SVM classifier. We present results for two datasets, Aim@Shape [1] and the Washington RGB-dobjectdataset [2], anddemonstrate the competitive performance of our method.
Unlike 2-dimensional (2d) images, direct 3-dimensional (3d) point cloud processing using deep neural network architectures is challenging, mainly due to the lack of explicit neighbor relationships. Many researchers at...
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Unlike 2-dimensional (2d) images, direct 3-dimensional (3d) point cloud processing using deep neural network architectures is challenging, mainly due to the lack of explicit neighbor relationships. Many researchers attempt to remedy this by performing an additional voxelization preprocessing step. However, this adds additional computational overhead and introduces quantization error issues, limiting an accurate estimate of the underlying structure of objects that appear in the scene. To this end, in this article, we propose a deep network that can directly consume raw unstructured point clouds to perform object classification and part segmentation. In particular, a deep Feature Transformation Network (dFT-Net) has been proposed, consisting of a cascading combination of edge convolutions and a feature transformation layer that captures the local geometric features by preserving neighborhood relationships among the points. The proposed network builds a graph in which the edges are dynamically and independently calculated on each layer. To achieve object classification and part segmentation, we ensure point order invariance while conducting network training simultaneously-the evaluation of the proposed network has been carried out on two standard benchmark datasets for object classification and part segmentation. The results were comparable to or better than existing state-of-the-art methodologies. The overall score obtained using the proposeddFT-Net is significantly improved compared to the state-of-the-art methods with the ModelNet40 dataset for objectcategorization.
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