一种复杂背景下的快速人脸检测算法

提出了一个由粗到细的多阶段人脸检测算法,介绍了检测工作的三个部分:肤色区域分割预处理、应用人脸基本特征检测和定位的人脸细检、平均脸模板匹配的人脸验证。实验证明该算法能有效检测出复杂环境中的人脸。该算法对于人脸的平移、缩放、适度旋转都能很好地适应。     

一种新型移动物体检测及背景建模系统

帧差法和背景减除法是目前应用较广的移动物体检测方法。针对背景建模中经常出现"拖尾"现象,结合帧差法提出了一种新的移动物体检测系统,并就该系统的可扩展性进行了深入分析,提出了一种实时帧保存算法。实验结果表明,该系统可以很好地抑制"拖尾"效应,并为其他算法在该系统上的应用提供了更好的基础条件。     

移动机器人无线实时反馈控制系统的设计

由于移动机器人左右两轮的非线性特征,其反馈调节无法克服这一特性,必须借助PC机来进行调节。为此提出了一种无线实时反馈控制方法,在PC机上加入PID控制算法,实现了对机器人的无线实时反馈控制。     

A bayesian approach to real-time obstacle avoidance for a mobile robot

Real-time obstacle avoidance is essential for the safe operation of mobile robots in a dynamically changing environment. This paper investigates how an industrial mobile robot can respond to unexpected static obstacles while following a path planned by a global path planner. The obstacle avoidance problem is formulated using decision theory to determine an optimal response based on inaccurate sensor data. The optimal decision rule minimises the Bayes risk by trading between a sidestep maneuver and backtracking to follow an alternative path. Real-time implementation is emphasised here as part of a framework for real world applications. It has been successfully implemented both in simulation and in reality using a mobile robot.     

Indoor scene recognition by a mobile robot through adaptive object detection

Mobile robotics has achieved notable progress, however, to increase the complexity of the tasks that mobile robots can perform in natural environments, we need to provide them with a greater semantic understanding of their surrounding. In particular, identifying indoor scenes, such as an Office or a Kitchen, is a highly valuable perceptual ability for an indoor mobile robot, and in this paper we propose a new technique to achieve this goal. As a distinguishing feature, we use common objects, such as Doors or furniture, as a key intermediate representation to recognize indoor scenes. We frame our method as a generative probabilistic hierarchical model, where we use object category classifiers to associate low-level visual features to objects, and contextual relations to associate objects to scenes. The inherent semantic interpretation of common objects allows us to use rich sources of online data to populate the probabilistic terms of our model. In contrast to alternative computer vision based methods, we boost performance by exploiting the embedded and dynamic nature of a mobile robot. In particular, we increase detection accuracy and efficiency by using a 3D range sensor that allows us to implement a focus of attention mechanism based on geometric and structural information. Furthermore, we use concepts from information theory to propose an adaptive scheme that limits computational load by selectively guiding the search for informative objects. The operation of this scheme is facilitated by the dynamic nature of a mobile robot that is constantly changing its field of view. We test our approach using real data captured by a mobile robot navigating in Office and home environments. Our results indicate that the proposed approach outperforms several state-of-the-art techniques for scene recognition.     

基于角点聚类的移动机器人自然路标检测与识别

针对未知环境中机器人视觉导航的自然路标检测,提出了一种基于角点聚类的自然路标局部特征提取、不变性表示及其匹配算法.用SUSAN算子提取左右视图中的角点,在极线约束下对左右视图的角点进行匹配,消除遮挡或噪声引起的角点;同时应用立体视觉计算角点视差,进一步筛选角点.根据角点聚类策略提取自然路标局部特征,并提出不随距离、角度变化的局部特征不变性表示及匹配方法.理论分析和实验结果表明,该算法具有较好的鲁棒性,在一定距离和角度变换下能够对路标进行正确识别.     

A real-time automatic pavement crack and pothole recognition system for mobile Android-based devices

Due to the rapid growth of vehicles and traffic accidents caused by road pavement defects, road safety has become a pressing concern worldwide. For this reason, Countries and Federal States have started focusing their resources on the analysis of civil infrastructures to assess their safety and serviceability. The analyses are performed by specialized teams of inspectors and structural engineers who manually inspect road infrastructures and provide detailed reports about the detected pavement distresses and their magnitudes. This work aims at providing a new system able to detect the framed distress using solely the computational resources provided by a mobile device To reach this goal, an automatic pavement distress recognition system based on the OpenCV library is developed and embedded in a mobile application, enabling the recognition of three common pavement distresses: Pothole, Longitudinal-Transversal Cracks, and Fatigue Cracks. Our method, tested on several Android mobile platforms, is able recognize the pavement distresses of interest reaching more than 0.7 of Precision, Recall, Accuracy, and F-Measure. This application promises to improve the on-site work of inspectors by decreasing the time required to perform inspections while ensuring, at the same time, a higher level of accuracy.     

A face detection and recognition system in color image series

A human face detection and recognition system for color image series is presented in this paper. The system is composed of two subsystems: human face detection subsystem and human face recognition subsystem. The face detection subsystem includes two modules: face finding and face verification. The human face finding module determines the face regions of a number of subjects from color image series using skin color analysis and motion analysis. The human face verification module is developed to verify the detected human faces by judging of eclipse and support vector machine (SVM), and precisely localize human faces by locating eyes and mouths based on Generalized Symmetry Transform. The features characterizing the relation between face patterns can be extracted and selected by Principal Component Analysis. Using these selected features to train multiple SVMs, we can finally classify human faces. Moreover, in these modules, several simple and complex methods are used to reduce the searching space. So the system can work at a high speed and high detection and recognition rate. Human face detection accuracy of the system is 97.2% under controllable lightning condition. Human face recognition accuracy of the system for 70 persons is 96.5% (with 20 eigenvectors) and 98.3% (with 30 eigenvectors).     

拟人机器人人脸识别系统研究

研究了人脸识别系统。基于拟人机器人人脸识别系统的工作流程,对人脸识别系统中人脸检测阶段所采用的Adaboost算法、人脸跟踪阶段采用的Camshift算法,以及人脸识别阶段所使用的PCA算法进行了探讨。采用了这些经典的算法后,该系统具有较高的识别率和系统性能。     

一种利用IMSI检测和人脸识别的手机防盗追踪系统研究

针对手机被盗带来的隐私数据泄露问题,提出了一种利用IMSI(international mobile subscriber identification number)检测和人脸识别的手机防盗追踪系统.针对IMSI检测,给出了一种分层—二分查找的查找方法,并在手机用户数据库上进行了多组对比实验,结果表明该方法具有较高的查找效率.针对人脸识别,提出了一种基于Gabor二值模式和分块加权的单样本人脸识别算法,该算法在FERET人脸数据库上表现出良好的识别性能.通过该系统可以确定被盗手机的位置和非法用户身份信息,提高了找回手机的可能性.     

Web-based mobile robot platform for real-time exercises

This paper introduces a new vision-based and web-based mobile robot platform. The platform consists of control and communication centers, a mobile robot and real-time support libraries. All activities in the platform are achieved by only computer vision techniques. The platform provides monitoring, tele-controlling and programming for real-time educational exercises and helps to the users to achieve these exercises through a standard web browser without any need for additional support software. The results have shown that the proposed, designed and implemented platform provide amazing new facilities and features to the users (students and researchers) in applying their real-time exercises on web.     

复杂背景下基于模糊集的快速人脸检测

针对如何在复杂背景下快速定位人脸并对其进行确认的问题,提出了一种基于模糊集的快速人脸检测方法.该方法利用肤色模型对图像进行肤色检测,获得肤色分割区域后,并利用数学形态学算子对分割区域进行处理并获得人脸候选区域,再结合模糊集理论,融合人脸的特征进行模糊事件的判断,确定人脸候选区域是否包含真正的人脸.实验结果表明,该算法具有较强的鲁棒性和高的正确检测率,并能满足实时应用的要求.     

复杂背景下基于肤色分割的人脸检测算法研究

针对复杂背景下的多姿态彩色人脸图像,提出了一种基于Adaboost级联分类器和模板匹配相结合的人脸检测算法.利用肤色信息对对图像中的皮肤区域和非皮肤区域进行分割,运用改进后的Adaboost方法定位可能的人脸区域.最后通过模板匹配的方法对检测到的人脸区域进行进一步验证,实现了彩色图像中更精确的人脸定位.在实验中从不同大小、背景、光照、表情和光源方向等方面对多姿态的人脸图像进行了检测,取得了很好的效果,表明了该算法的有效性和实用性.     

A relative localisation system of a mobile robot

This paper describes a localisation system applied to vehicle displacements on irregular grounds and at moderate speed (about 1 m/s). It is composed of a gyrometer and a Doppler sensor, which give, by integration, the attitude and position of the vehicle supporting them, without contact with the ground. The precision of the obtained localisation is about 2% for ranges of about a hundred meters.     

An integrated automatic face detection and recognition system

This paper proposes an integrated system for unconstrained face recognition in complex scenes. The scale and orientation tolerant system comprises a face detector followed by a recognizer. Given a color input image of a person, the face detector encloses the face from the complex scene within a circular boundary, and locates the position of the nose. A radial grid mapping centered on the nose is then performed to extract a feature vector within the boundary. The feature vector is input to a radial basis function neural network classifier for face identification. The proposed face detector achieved an average detection rate of 95.8% while the face recognizer achieved an average recognition rate of 97.5% on a database of 21 persons with variations in scale, orientation, natural illumination and background. The two modules were combined to form an automatic face recognition system that was evaluated in the context of a security system using a video database of 21 users and 10 intruders, acquired in an unconstrained environment. A recognition rate of 93.5% with 0% false acceptance rate was achieved.     

CFSM: a novel frame analyzing mechanism for real-time face recognition system on the embedded system

The development of web cameras and smart phones is mature, and more and more facial recognition-related applications are implemented on embedded systems. The demand for real-time face recognition on embedded systems is also increasing. In order to improve the accuracy of face recognition, most of the modern face recognition systems consist of multiple deep neural network models for recognition. However, in an embedded system, integrating these complex neural network models and execute simultaneously is not easy to achieve the goal of real-time recognition of human faces and their identities. In view of this, this study proposes a new frame analysis mechanism, continuous frames skipping mechanism (CFSM), which can analyze the frame in real time to determine whether it is necessary to perform face recognition on the current frame. Through the analysis of CFSM, the frames that do not need to be re-recognized for face are omitted. In this way, the workload of the face recognition system will be greatly reduced to achieve the goal of real-time face recognition in the embedded system. The experimental results show that the proposed CFSM mechanism can greatly increase the speed of face recognition in the video on the embedded system, achieving the goal of real-time face recognition.

     

Target recognition by components for mobile robot navigation

This paper presents a vision-based technique for detecting targets of the environment which have to be reached by an autonomous mobile robot during its navigational tasks. The targets the robot has to reach are the doors of the authors' office building. The detection of the door has been performed by detecting its most significant components in the image and it is based on data classification. Two neural classifiers have been trained for recognizing single components of the door. Then a combining algorithm, based on heuristic considerations, checks that they are in the proper geometric configuration of the structure of the door. The novelty of this work is to use together colour and shape information for identifying features and for detecting the components of the target. The approach, based on learning by components, is able to cleverly solve the problems of scale changes, perspective variations and partial occlusions. The obtained detecting system has been tested on a large test set of real images showing a high reliability and robustness: doors of different rooms, under different illumination conditions and by different viewpoints have been successfully recognized. Results in terms of door detection rate and false positive rate are presented throughout the paper.     

Hyperspectral-cube-based mobile face recognition: A comprehensive review

With the hyperspectral sensor technology evolving and becoming more cost-effective, hyperspectral imaging offers new opportunities for robust face recognition. Hyperspectral face cubes contain much more spectral information than face images from common RGB color cameras. Hyperspectral face recognition is robust to the impacts, such as illumination, pose, occlusion, and spoofing, which can heavily avoid the limitations of the visible-image-based face recognition.In this paper, we summarize the spectrum properties of hyperspectral face cubes and survey the hyperspectral face recognition methods in the literature. We categorize them into major groups for better understanding. We overview the existing hyperspectral face datasets, and establish our own dataset. We also discuss efficient neural networks used for mobile face recognition and conduct experiments on mobile hyperspectral face recognition. Results show that under harsh conditions like large illumination changing and pose variation, hyperspectral-cube-based methods have higher recognition accuracy than visible-image-based methods. Finally, we deliver insightful discussions and prospects for future works on mobile hyperspectral face recognition.