Despite impressive advances in simultaneous localization and mapping, dense robotic mapping remains challenging due to its inherent nature of being a high-dimensional inference problem. In this paper, we propose a dense semantic robotic mapping technique that exploits sparse Bayesian models, in particular, the relevance vector machine, for high-dimensional sequential inference. The technique is based on the principle of automatic relevance determination and produces sparse models that use a small subset of the original dense training set as the dominant basis. The resulting map posterior is continuous, and queries can be made efficiently at any resolution. Moreover, the technique has probabilistic outputs per semantic class through Bayesian inference. We evaluate the proposed relevance vector semantic map using publicly available benchmark datasets, NYU Depth V2 and KITTI; and the results show promising improvements over the state-of-the-art techniques.
A common feature of the works mentioned earlier is the discretization of the space prior to map inference which means, once the map is inferred, the prediction cannot be computed at any arbitrary points. In this paper, we propose a novel and alternative solution for the problem of dense 3D map building that is continuous and at the same time sparse. RVSM incrementally learns relevance vectors which are dominant basis in the data, and builds a sparse Bayesian model of the 3D map. As a result, the prediction can be made efficiently at any desired location. The training process that is often more expensive is accelerated by utilizing a sequential sparse Bayesian learning algorithm in @cite_22 . We evaluate RVSM using NYU Depth V2 (NYUDv2) @cite_6 and KITTI datasets and compare the achieved results with the recent works mentioned here.
@cite_22 @cite_6
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We consider the problem of dense depth prediction from a sparse set of depth measurements and a single RGB image. Since depth estimation from monocular images alone is inherently ambiguous and unreliable, to attain a higher level of robustness and accuracy, we introduce additional sparse depth samples, which are either acquired with a low-resolution depth sensor or computed via visual Simultaneous Localization and Mapping (SLAM) algorithms. We propose the use of a single deep regression network to learn directly from the RGB-D raw data, and explore the impact of number of depth samples on prediction accuracy. Our experiments show that, compared to using only RGB images, the addition of 100 spatially random depth samples reduces the prediction root-mean-square error by 50 on the NYU-Depth-v2 indoor dataset. It also boosts the percentage of reliable prediction from 59 to 92 on the KITTI dataset. We demonstrate two applications of the proposed algorithm: a plug-in module in SLAM to convert sparse maps to dense maps, and super-resolution for LiDARs. Software and video demonstration are publicly available. We consider the problem of dense depth prediction from a sparse set of depth measurements and a single RGB image. Since depth estimation from monocular images alone is inherently ambiguous and unreliable, to attain a higher level of robustness and accuracy, we introduce additional sparse depth samples, which are either acquired with a low-resolution depth sensor or computed via visual Simultaneous Localization and Mapping (SLAM) algorithms. We propose the use of a single deep regression network to learn directly from the RGB-D raw data, and explore the impact of number of depth samples on prediction accuracy. Our experiments show that, compared to using only RGB images, the addition of 100 spatially random depth samples reduces the prediction root-mean-square error by 50 on the NYU-Depth-v2 indoor dataset. It also boosts the percentage of reliable prediction from 59 to 92 on the KITTI dataset. We demonstrate two applications of the proposed algorithm: a plug-in module in SLAM to convert sparse maps to dense maps, and super-resolution for LiDARs. Software22https: github.com fangchangma sparse-to-dense and video demonstration33https: www.youtube.com watch?v=vNIIT_M7×7Y are publicly available. This paper presents a novel probabilistic foundation for volumetric 3D reconstruction. We formulate the problem as inference in a Markov random field, which accurately captures the dependencies between the occupancy and appearance of each voxel, given all input images. Our main contribution is an approximate highly parallelized discrete-continuous inference algorithm to compute the marginal distributions of each voxel's occupancy and appearance. In contrast to the MAP solution, marginals encode the underlying uncertainty and ambiguity in the reconstruction. Moreover, the proposed algorithm allows for a Bayes optimal prediction with respect to a natural reconstruction loss. We compare our method to two state-of-the-art volumetric reconstruction algorithms on three challenging aerial datasets with LIDAR ground truth. Our experiments demonstrate that the proposed algorithm compares favorably in terms of reconstruction accuracy and the ability to expose reconstruction uncertainty. Inferring the underlying depth map from a single image is an ill-posed and inherently ambiguous problem. State-of-the-art deep learning methods can now estimate accurate depth maps, but when projected into 3D, still lack local detail and are often highly distorted. We propose a multi-scale convolution neural network to learn from single RGB images fine-scaled depth maps that result in realistic 3D reconstructions. To encourage spatial coherency, we introduce spatial coordinate feature maps and a local relative depth constraint. In our network, the three scales are closely integrated with skip fusion layers, making it highly efficient to train with large-scale data. Experiments on the NYU Depth v2 dataset shows that our depth predictions are not only competitive with state-of-the-art but also leading to 3D reconstructions that are accurate and rich with detail.