Massive visual traffic data have become available recently. Though it opens the realm of intelligent traffic analysis, processing the data in a timely manner is difficult yet critical to time sensitive decisions, which are typical to traffic related management. In this paper, we study time-bounded aggregation analytics on large visual traffic data including traffic images and videos. We first find that current MapReduce framework can not work well due to two challenges: first, significant dual diversities exist on data distributions and processing time; second, apriori knowledge on these distributions and time costs are not always available. However, we also observe spatial and temporal locality on data values and processing time. Based on the examination, we design Traffic At-a-Glance (TaG), an augmented MapReduce framework for time-bounded traffic analytics jobs. Particularly, we propose a novel sampling algorithm that exploits traffic data localities and stratifies samples based on data distributions and processing time. It runs in an iterative, adaptive manner without apriori knowledge. Moreover, we propose a heuristic scheduling algorithm with considerations of batch processing overhead. Further, we refine the load balancing mechanism based on data processing time locality to respect job time bounds. In addition, we extend TaG to well handle traffic videos by sampling video data based on motion information encoded in the videos. We implement TaG on Hadoop and conduct extensive experiments on a large visual traffic dataset. The evaluations on different data sizes show TaG is able to achieve high accuracy within time bounds.

Following a person is a fundamental requirement for human-robot interaction. In this paper we propose a novel tracking approach for robust human feet tracking which integrates human locomotion into tracking algorithms. The vertical displacement between the two feet is analyzed and we observe that this displacement during the walking cycle is close to a modulated cosine waveform. Based on this, we propose an adaptive model for the human walking pattern. We divide the motion of the human feet into local motion and global motion. The local motion is modeled by a modified cosine wave that updates along time. Global motion is estimated by the continuity between successive frames. This model is combined with particle filtering to guide the searching of the feet. A 2D Gaussian mask is generated according to the predicted position estimated by the motion model and used to modify the weight of the particles. Experiments are implemented in several human walking videos and the algorithm is evaluated against the generic particle filtering method. Results show that the feet can be tracked successfully with significant improvements compared to the generic particle filtering method.

Human tracking in video has many practical applications such as visual guided navigation, assisted living, etc. In such applications, it is necessary to accurately track multiple humans across multiple cameras, subject to real-time constraints. Despite recent advances in visual tracking research, the tracking systems purely relying on visual information fail to meet the accuracy and real-time requirements at the same time. In this paper, we present a novel accurate and real-time human tracking system called VM-Tracking. The system aggregates the information of motion (M) sensor on human, and integrates it with visual (V) data based on physical locations. The system has two key features, i.e. location-based VM fusion and appearance-free tracking, which significantly distinguish itself from other existing human tracking systems. We have implemented the VM-Tracking system and conducted comprehensive experiments on challenging scenarios.

This paper presents a novel video-based face recognition algorithm by using a sequential sampling and updating scheme, named sequential sample consensus. The proposed algorithm aims at providing a sequential scheme that can be applied to streaming video data. Different from existing approaches, the training video sequences serve as the sample space, and the person's identity in the testing sequence is characterized using an identity probability mass function (PMF) that is sequentially updated. For each testing frame, samples are randomly drawn from the sample space, and the numbers of samples for each identity are determined by the identity PMF. The testing frame is evaluated against the drawn samples to calculate the weights, and the sample weights are used for updating the identity PMF. Benefiting from the sampling procedure, the change in both the numbers and the weights of the samples for each individual leads to quick reaction of the algorithm. The proposed algorithm is robust against misclassification caused by pose variations, and sensitive to identity switching during recognition. The algorithm is evaluated using both public and self-made datasets, and shows better performance than other video-based face recognition approaches.

This paper presents a novel video-based face recognition algorithm using a sequential sampling and updating scheme, named sequential sample consensus (SSC). Different from the existing approaches, the training video sequences serve as the sample space, and the person's identity in the testing sequence is characterized by an identity probability mass function (PMF) that is sequentially updated. For each testing frame, samples are randomly drawn from the sample space with the numbers of samples for each identity determined by the identity PMF. The testing frame is evaluated against the drawn samples to calculate the weights, and the sample weights are utilized for updating the identity PMF. The proposed algorithm is robust against misclassification caused by pose variations, and sensitive to identity switching during recognition. The algorithm is evaluated using both public and self-made databases, and shows better performance than other video-based face recognition approaches.

This paper provides a novel side-view face authentication method based on discrete wavelet transform and random forest. A subset selection method that increases the number of training samples and allows subsets to preserve the global information is presented. The authentication method can be summarized to have the following steps: profile extraction, wavelet decomposition, subset splitting and random forest verification. The new method takes the advantage of wavelet's localization property in both frequency and spatial domains, while maintaining the generalized properties of random forest. The implementation of the proposed method is computationally feasible and the experimental results show that the performance is satisfactory. Future improvements are discussed in the paper.