Data Mining Practical Machine Learning Tools and Techniques

Point clouds provide a flexible geometric representation suitable for countless applications in computer graphics; they also comprise the raw output of most 3D data acquisition devices. While hand-designed features on point clouds have long been proposed in graphics and vision, however, the recent overwhelming success of convolutional neural networks (CNNs) for image analysis suggests the value of adapting insight from CNN to the point cloud world. Point clouds inherently lack topological information, so designing a model to recover topology can enrich the representation power of point clouds. To this end, we propose a new neural network module dubbed EdgeConv suitable for CNN-based high-level tasks on point clouds, including classification and segmentation. EdgeConv acts on graphs dynamically computed in each layer of the network. It is differentiable and can be plugged into existing architectures. Compared to existing modules operating in extrinsic space or treating each point independently, EdgeConv has several appealing properties: It incorporates local neighborhood information; it can be stacked applied to learn global shape properties; and in multi-layer systems affinity in feature space captures semantic characteristics over potentially long distances in the original embedding. We show the performance of our model on standard benchmarks, including ModelNet40, ShapeNetPart, and S3DIS.

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Dynamic Graph CNN for Learning on Point Clouds

On robust estimation of the location parameter

From the Publisher: 
The accessible presentation of this book gives both a general view of the entire computer vision enterprise and also offers sufficient detail to be able to build useful applications. Users learn techniques that have proven to be useful by first-hand experience and a wide range of mathematical methods. A CD-ROM with every copy of the text contains source code for programming practice, color images, and illustrative movies. Comprehensive and up-to-date, this book includes essential topics that either reflect practical significance or are of theoretical importance. Topics are discussed in substantial and increasing depth. Application surveys describe numerous important application areas such as image based rendering and digital libraries. Many important algorithms broken down and illustrated in pseudo code. Appropriate for use by engineers as a comprehensive reference to the computer vision enterprise.

Computer vision : a modern approach = 计算机视觉 : 一种现代的方法

Object detection, one of the most fundamental and challenging problems in computer vision, seeks to locate object instances from a large number of predefined categories in natural images. Deep learning techniques have emerged as a powerful strategy for learning feature representations directly from data and have led to remarkable breakthroughs in the field of generic object detection. Given this period of rapid evolution, the goal of this paper is to provide a comprehensive survey of the recent achievements in this field brought about by deep learning techniques. More than 300 research contributions are included in this survey, covering many aspects of generic object detection: detection frameworks, object feature representation, object proposal generation, context modeling, training strategies, and evaluation metrics. We finish the survey by identifying promising directions for future research.

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Deep Learning for Generic Object Detection: A Survey

As a long-standing problem, infrared small target detection is challenging due to the dimness of targets and the complexity of background. Considering the limitation of traditional approaches, we propose an accurate and robust method for infrared small target detection using multiscale gray and variance difference measures. A multiscale adaptive gray difference measure is first used to enhance small targets and improve detection accuracy. Then, a multiscale variance difference measure is proposed to alleviate the impact of background fluctuation and improve the robustness of our method. By integrating these two approaches, targets can be extracted accurately using a threshold-adaptive segmentation. Extensive experiments have been conducted on datasets with various scenes. Results have demonstrated the effectiveness and outperformance of our method as compared to the state-of-the-art methods.

Robust Infrared Small Target Detection Using Multiscale Gray and Variance Difference Measures

EI3D: Expression-invariant 3D face recognition based on feature and shape matching

Recently, the performance of single image super-resolution (SR) has been significantly improved with powerful networks. However, these networks are developed for image SR with a single specific integer scale (e.g., x2;x3,x4), and cannot be used for non-integer and asymmetric SR. In this paper, we propose to learn a scale-arbitrary image SR network from scale-specific networks. Specifically, we propose a plug-in module for existing SR networks to perform scale-arbitrary SR, which consists of multiple scale-aware feature adaption blocks and a scale-aware upsampling layer. Moreover, we introduce a scale-aware knowledge transfer paradigm to transfer knowledge from scale-specific networks to the scale-arbitrary network. Our plug-in module can be easily adapted to existing networks to achieve scale-arbitrary SR. These networks plugged with our module can achieve promising results for non-integer and asymmetric SR while maintaining state-of-the-art performance for SR with integer scale factors. Besides, the additional computational and memory cost of our module is very small.

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Learning a Single Network for Scale-Arbitrary Super-Resolution

Recognizing 3D objects from point clouds in the presence of significant clutter and occlusion is a highly challenging task. In this paper, we present a coarse-to-fine 3D object recognition algorithm. During the phase of offline training, each model is represented with a set of multi-scale local surface features. During the phase of online recognition, a set of keypoints are first detected from each scene. The local surfaces around these keypoints are further encoded with multi-scale feature descriptors. These scene features are then matched against all model features to generate recognition hypotheses, which include model hypotheses and pose hypotheses. Finally, these hypotheses are verified to produce recognition results. The proposed algorithm was tested on two standard datasets, with rigorous comparisons to the state-of-the-art algorithms. Experimental results show that our algorithm was fully automatic and highly effective. It was also very robust to occlusion and clutter. It achieved the best recognition performance on all of these datasets, showing its superiority compared to existing algorithms.

https://www.mdpi.com/1424-8220/14/12/24156/pdf

Recognizing Objects in 3D Point Clouds with Multi-Scale Local Features

To perform registration of structured point clouds with large rotation and small overlaps, this paper presents an algorithm based on the direction angles and the projection information of dense points. This algorithm fully employs the geometric information of structured environment. It consists of two parts: rotation estimation and translation estimation. For rotation estimation, a direction angle is defined for a point cloud and then the rotation matrix is obtained by comparing the difference between the distributions of angles. For translation estimation, the point clouds are projected onto three orthogonal planes and then a correlation operation is performed on the projection images to calculate the translation vector. Experiments have been conducted on several datasets. Experimental results demonstrate that the proposed algorithm outperforms the state-of-the-art approaches in terms of both accuracy and efficiency.

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Yulan Guo

Papers

Robust Infrared Small Target Detection Using Multiscale Gray and Variance Difference Measures

EI3D: Expression-invariant 3D face recognition based on feature and shape matching

Learning a Single Network for Scale-Arbitrary Super-Resolution

Recognizing Objects in 3D Point Clouds with Multi-Scale Local Features

Fast and Accurate Registration of Structured Point Clouds with Small Overlaps