基于Kinect与Dobot机械臂的人机交互系统

文中系统主要为通过Kinect体感器捕获人体手的坐标移动以及手势变化,利用坐标转化等手段,将其转化为指令发送到Dobot机械臂,使其能够在非特定条件下,按照人体手的轨迹做特定运动,并进行抓取物体等功能。系统中的Kinect体感器获取坐标为三维空间中的人体手的移动轨迹,使得Dobot的机械臂运动更加贴近人体实际操作,大大加强了实用价值。另外Kinect还将获取人体手势,用于控制Dobot末端夹具的开合。     

基于Kinect骨架信息的人体动作识别

深度图像属计算机视觉研究范畴,数据表达方式有一定差异,其现有图像处理算法多可借鉴和扩展。本文在深度图像基础上,对人体运动特征模型和识别算法进行研究,为动作识别思路和方法提供参考,重点分析Kinect深度图像获取Kinect人体关节点识别。     

基于Kinect和金字塔特征的行为识别算法

提出了一种基于Kinect和金字塔特征的行为识别算法。在算法中,Kinect不仅能够获得RGB信息,还能获得与RGB信息对应的深度信息;而金字塔特征不仅描述了人体行为的全局形状和局部细节信息,而且还描述了人体行为的空间信息。通过不同核函数的支持向量机(SVM)分类器在具有挑战性的DHA数据集的试验结果表明,金字塔特征在RGB和深度图上都能获得令人满意的性能,且当深度特征和RGB特征融合时,其性能获得了进一步的提高,识别率达到96.2%,远高于一些具有代表性的行为描述子。     

基于Kinect深度技术的障碍物在线快速检测算法

针对在未知环境中移动机器人自主导航面临的障碍物实时检测问题,提出了一种基于Kinect深度技术的障碍物在线快速检测算法。在深度摄像机标定基础上,分析了摄像机运动造成视频流中的场景变化,重点研究了室内动态背景下的Kinect深度图像特征和障碍物在线快速检测。建立室内动态背景模型,采用背景减除法和连通体分析提取障碍物并归类,实现了对Kinect视频序列图像的在线快速检测。以轮式移动机器人为实验平台,验证了所提出算法的实时性、准确性和鲁棒性。     

手势识别技术在物联网课程教学中的应用

人体手势是一种自然并且直观的人际交流模式,最新的Kinect设备可提供一种新的人机交互的方式,能够捕捉、跟踪以及解密人体的动作、手势以及声音。文章利用Kinect进行人体手势识别,在物联网课程的日常教学上提供无接触式互动。     

基于Kinect的虚拟试衣系统设计与实现

本项目主要通过Kinect摄像头捕获人体数据,彩色数据和深度数据,对采集到的数据作处理,生成人体骨骼模型,方便对人体骨骼定位;进而设计算法使衣服图像适配人体,再根据识别人体手势,做逻辑处理之后,然后通过Kinect体感器将信息发送给PC,形成操作命令,最终使人体可以操控衣服。本项目的 Kinect虚拟试衣不仅可以让用户试看衣服的款式,还可以通过体感技术实时与外界进行交互,从而让试衣过程更加便捷和逼真。整个系统可广泛应用在家庭、商场及网络购物等场景中。     

基于Kinect的实时人体姿势识别

Kinect的实时骨骼跟踪技术获取身体关节点的三维位置信息,为进行人体姿势识别提供了丰富的信息,拟在三维关节点位置信息的基础上,建立一种实时的人体姿势识别系统。选择关节角度作为姿势特征,结合逻辑回归（logistic regression,LR）分类算法对54种姿势进行识别研究。实验结果表明,该姿势识别系统可以准确实时地识别人体姿势。     

基于Kinect的人体动作识别算法研究

针对现有的复杂背景下人体动作识别中存在识别准确率不高和实时性不强等问题,提出基于Kinect骨骼数据的改进动作识别算法。通过Kinect获取骨骼数据,提取出人体关节的特征向量,然后用模板匹配的方法对人体动作进行识别。通过搭建机器人体感控制系统验证了算法的可行性。在相同实验条件下测得算法的平均识别率为95.2%,平均识别时间为32.5ms。与其它动作识别算法比较,证明了算法的识别率较高、实时性较好。     

基于DBSCAN与梯度划分的Kinect障碍物轮廓检测算法

针对移动机器人的环境检测和避障问题中传感器获取的信息不够全面及准确,无法准确提供周围环境信息等问题,文中提出了利用Kinect传感器来获取周围环境的色彩信息和深度数据,并且提出了一种利用梯度划分和DBSCAN聚类方法来处理Kinect传感器获得的深度数据图。该算法首先使用梯度障碍物边缘检测方法对Kinect获取得到的深度图进行快速高效的处理障碍物边缘轮廓,并对算法中的差分参数进行改进,使得计算得到的梯度结果更准确。然后对比不同的聚类方法,使用BDSCAN聚类方法来对检测划分完毕的障碍物进行聚类分析,最后通过安排具体实验对该算法进行验证。实验结果表明,该算法能够对周围环境障碍物进行准确划分,可行区域效果明显,对不同物体的成功检测率较高,验证了算法的有效性。     

基于深度学习的人体骨架动作识别

基于人体骨架的动作识别具有鲁棒性和视点不变性的优点,为进一步提高骨架动作识别的识别率,打破以往大部分基于深度学习的方法的输入内容为人体关节坐标的局限性,文中提出一种将几何特征与LSTM网络结合的人体骨架动作识别算法。该算法选择基于关节与选定直线之间距离的几何特征作为网络的输入,引入了一种时间选择LSTM网络进行训练。利用时间选择LSTM网络拥有选出最具识别性时间段特征的能力,在SBU Interaction数据集和UT Kinect数据集上分别取得了99.36%和99.20%的识别率。实验结果证明了该方法对人体骨架动作识别的有效性。     

A Novel Character Segmentation Method for Text Images Captured by Cameras

Due to the rapid development of mobile devices equipped with cameras, instant translation of any text seen in any context is possible. Mobile devices can serve as a translation tool by recognizing the texts presented in the captured scenes. Images captured by cameras will embed more external or unwanted effects which need not to be considered in traditional optical character recognition (OCR). In this paper, we segment a text image captured by mobile devices into individual single characters to facilitate OCR kernel processing. Before proceeding with character segmentation, text detection and text line construction need to be performed in advance. A novel character segmentation method which integrates touched character filters is employed on text images captured by cameras. In addition, periphery features are extracted from the segmented images of touched characters and fed as inputs to support vector machines to calculate the confident values. In our experiment, the accuracy rate of the proposed character segmentation system is 94.90%, which demonstrates the effectiveness of the proposed method.     

Learning skeleton information for human action analysis using Kinect

Human action recognition plays an important role in modern intelligent systems, such as human–computer interaction (HCI), sport analysis, and somatosensory game. Compared with conventional 2-D based human action analysis, using Kinect sensor can obtain depth information of human action, which is significant for human action recognition. In this paper, we propose a joint angle sequence model for recognizing human actions, where depth images are acquired by using Kinect sensor. We design an improved DTW method to improve the matching accuracy. Comprehensive experiments show the effectiveness and robustness of our proposed method.     

Depth image super-resolution algorithm based on structural features and non-local means

The resolution and quality of the depth map captured by depth cameras are limited due to sensor hardware limitations, which becomes a roadblock for further computer vision applications. In order to solve this problem, we propose a new method to enhance low-resolution depth maps using high-resolution color images. The structural-aware term is introduced because of the availability of structural information in color images and the assumption of identical structural features within local neighborhoods of color images and depth images captured from the same scene. We integrate the structural-aware term with color similarity and depth similarity within local neighborhoods to design a local weighting filter based on structural features. To use non-local self-similarity of images, the local weighting filter is combined with the concept of non-local means, and then a non-local weighting filter based on structural features is designed. Some experimental results show that super-resolution depth image can be reconstructed well by the process of the non-local filter and the local filter based on structural features. The proposed method can reconstruct much better high-resolution depth images compared with previously reported methods.     

Human pose estimation and its application to action recognition: A survey

Human pose estimation aims at predicting the poses of human body parts in images or videos. Since pose motions are often driven by some specific human actions, knowing the body pose of a human is critical for action recognition. This survey focuses on recent progress of human pose estimation and its application to action recognition. We attempt to provide a comprehensive review of recent bottom-up and top-down deep human pose estimation models, as well as how pose estimation systems can be used for action recognition. Thanks to the availability of commodity depth sensors like Kinect and its capability for skeletal tracking, there has been a large body of literature on 3D skeleton-based action recognition, and there are already survey papers such as [1] about this topic. In this survey, we focus on 2D skeleton-based action recognition where the human poses are estimated from regular RGB images instead of depth images. We summarize the performance of recent action recognition methods that use pose estimated from color images as input, then show that there is much room for improvements in this direction.     

Computational cameras: convergence of optics and processing

A computational camera uses a combination of optics and processing to produce images that cannot be captured with traditional cameras. In the last decade, computational imaging has emerged as a vibrant field of research. A wide variety of computational cameras has been demonstrated to encode more useful visual information in the captured images, as compared with conventional cameras. In this paper, we survey computational cameras from two perspectives. First, we present a taxonomy of computational camera designs according to the coding approaches, including object side coding, pupil plane coding, sensor side coding, illumination coding, camera arrays and clusters, and unconventional imaging systems. Second, we use the abstract notion of light field representation as a general tool to describe computational camera designs, where each camera can be formulated as a projection of a high-dimensional light field to a 2-D image sensor. We show how individual optical devices transform light fields and use these transforms to illustrate how different computational camera designs (collections of optical devices) capture and encode useful visual information.     

Robust face anti-spoofing with depth information

With the prevalence of face authentication applications, the prevention of malicious attack from fake faces such as photos or videos, i.e., face anti-spoofing, has attracted much attention recently. However, while an increasing number of works on the face anti-spoofing have been reported based on 2D RGB cameras, most of them cannot handle various attacking methods. In this paper we propose a robust representation jointly modeling 2D textual information and depth information for face anti-spoofing. The textual feature is learned from 2D facial image regions using a convolutional neural network (CNN), and the depth representation is extracted from images captured by a Kinect. A face in front of the camera is classified as live if it is categorized as live using both cues. We collected a face anti-spoofing experimental dataset with depth information, and reported extensive experimental results to validate the robustness of the proposed method.     

3D depth image analysis for indoor fall detection of elderly people

This paper presents a new fall detection method of elderly people in a room environment based on shape analysis of 3D depth images captured by a Kinect sensor. Depth images are pre-processed by a median filter both for background and target. The silhouette of moving individual in depth images is achieved by a subtraction method for background frames. The depth images are converted to disparity map, which is obtained by the horizontal and vertical projection histogram statistics. The initial floor plane information is obtained by V disparity map, and the floor plane equation is estimated by the least square method. Shape information of human subject in depth images is analyzed by a set of moment functions. Coefficients of ellipses are calculated to determine the direction of individual. The centroids of the human body are calculated and the angle between the human body and the floor plane is calculated. When both the distance from the centroids of the human body to the floor plane and the angle between the human body and the floor plane are lower than some thresholds, fall incident will be detected. Experiments with different falling direction are performed. Experimental results show that the proposed method can detect fall incidents effectively.     

Human Activity Recognition Using Body Joint‐Angle Features and Hidden Markov Model

This paper presents a novel approach for human activity recognition (HAR) using the joint angles from a 3D model of a human body. Unlike conventional approaches in which the joint angles are computed from inverse kinematic analysis of the optical marker positions captured with multiple cameras, our approach utilizes the body joint angles estimated directly from time‐series activity images acquired with a single stereo camera by co‐registering a 3D body model to the stereo information. The estimated joint‐angle features are then mapped into codewords to generate discrete symbols for a hidden Markov model (HMM) of each activity. With these symbols, each activity is trained through the HMM, and later, all the trained HMMs are used for activity recognition. The performance of our joint‐angle–based HAR has been compared to that of a conventional binary and depth silhouette‐based HAR, producing significantly better results in the recognition rate, especially for the activities that are not discernible with the conventional approaches.