The High Performance Computing as a Service provides the computing power to client applications on a pay-per-use basis. Contemporary high-performance servers gain high computing power by applying multi-core processors, graphics processors and FPGA accelerators. But efficient utilization of computing resources requires adequate management methods. In this paper, we propose a new method of scheduling IoT distributed applications in the heterogeneous cloud environment. We assume that applications, which have been requested for execution, are specified as directed acyclic graphs. Our method dynamically schedules all tasks using resource sharing by the applications. The goal of scheduling is to minimize the cost of resource hiring and to minimize the latency of all activated applications. Experimental results showed that our method gives significantly better utilization of computational resources than existing management methods for clouds. Thus, the cost of using the cloud can be reduced.

We present Argoverse, a dataset designed to support autonomous vehicle perception tasks including 3D tracking and motion forecasting. Argoverse includes sensor data collected by a fleet of autonomous vehicles in Pittsburgh and Miami as well as 3D tracking annotations, 300k extracted interesting vehicle trajectories, and rich semantic maps. The sensor data consists of 360 degree images from 7 cameras with overlapping fields of view, forward-facing stereo imagery, 3D point clouds from long range LiDAR, and 6-DOF pose. Our 290km of mapped lanes contain rich geometric and semantic metadata which are not currently available in any public dataset. All data is released under a Creative Commons license at Argoverse.org. In baseline experiments, we use map information such as lane direction, driveable area, and ground height to improve the accuracy of 3D object tracking. We use 3D object tracking to mine for more than 300k interesting vehicle trajectories to create a trajectory forecasting benchmark. Motion forecasting experiments ranging in complexity from classical methods (k-NN) to LSTMs demonstrate that using detailed vector maps with lane-level information substantially reduces prediction error. Our tracking and forecasting experiments represent only a superficial exploration of the potential of rich maps in robotic perception. We hope that Argoverse will enable the research community to explore these problems in greater depth.

Video-based person re-identification matches video clips of people across non-overlapping cameras. Most existing methods tackle this problem by encoding each video frame in its entirety and computing an aggregate representation across all frames. In practice, people are often partially occluded, which can corrupt the extracted features. Instead, we propose a new spatiotemporal attention model that automatically discovers a diverse set of distinctive body parts. This allows useful information to be extracted from all frames without succumbing to occlusions and misalignments. The network learns multiple spatial attention models and employs a diversity regularization term to ensure multiple models do not discover the same body part. Features extracted from local image regions are organized by spatial attention model and are combined using temporal attention. As a result, the network learns latent representations of the face, torso and other body parts using the best available image patches from the entire video sequence. Extensive evaluations on three datasets show that our framework outperforms the state-of-the-art approaches by large margins on multiple metrics.

The methodology for finding the same individual in a network of cameras must deal with significant changes in appearance caused by variations in illumination, viewing angle, and a person's pose. Re-identification requires solving two fundamental problems: 1) determining a distance measure between features extracted from different cameras that cope with illumination changes (metric learning) and 2) ensuring that matched features refer to the same body part (correspondence). Most metric learning approaches focus on finding a robust distance measure between bounding box images, neglecting the alignment aspects. In this paper, we propose to learn appearance measures for patches that are combined using deformable models. Learning metrics for patches avoids strong dimensionality reduction, thus keeping more information. Additionally, we allow patches to change their locations, directly addressing the correspondence problem. As patches from different locations may share the same metric, our method effectively multiplies the amount of training data and allows patch metrics to be learned on the smaller amounts of labeled images. Different metric learning approaches (KISSME, XQDA, and LSSL) together with different deformable models (spring constraints and one-to-one matching constraints) are investigated and compared. For describing patches, we propose to learn a deep feature representation with convolutional neural networks, thus obtaining highly effective features for re-identification. We demonstrate that our approach significantly outperforms state-of-the-art methods on multiple data sets.

Re-identification of people in surveillance footage must cope with drastic variations in color, background, viewing angle and a persons pose. Supervised techniques are often the most effective, but require extensive annotation which is infeasible for large camera networks. Unlike previous supervised learning approaches that require hundreds of annotated subjects, we learn a metric using a novel one-shot learning approach. We first learn a deep texture representation from intensity images with Convolutional Neural Networks (CNNs). When training a CNN using only intensity images, the learned embedding is color-invariant and shows high performance even on unseen datasets without fine-tuning. To account for differences in camera color distributions, we learn a color metric using a single pair of ColorChecker images. The proposed one-shot learning achieves performance that is competitive with supervised methods, but uses only a single example rather than the hundreds required for the fully supervised case. Compared with semi-supervised and unsupervised state-of-the-art methods, our approach yields significantly higher accuracy.

Re-identification methods often require well aligned, unoccluded detections of an entire subject. Such assumptions are impractical in real world scenarios, where people tend to form groups. To circumvent poor detection performance caused by occlusions, we use fixed regions of interest and employ codebook-based visual representations. We account for illumination variations between cameras using a coupled clustering method that learns per-camera codebooks with entries that correspond across cameras. Because predictable movement patterns exist in many scenarios, we also incorporate temporal context to improve re-identification performance. This includes learning expected travel times directly from data and using mutual exclusion constraints to encourage solutions that maintain temporal ordering. Our experiments illustrate the merits of the proposed approach in challenging re-identification scenarios including crowded public spaces.

Characterizing an image region by its feature intercorrelations is a modern trend in computer vision. In this paper, we introduce a new image descriptor that can be seen as a natural extension of a standard covariance descriptor with the advantage of capturing nonlinear and nonmonotone dependencies. Inspired from the recent advances in mathematical statistics of Brownian motion, we can express highly complex structural information in a compact and computationally efficient manner. We show that our Brownian covariance descriptor can capture richer image characteristics than the covariance descriptor. Additionally, a detailed analysis of the Brownian manifold reveals that opposite to the classical covariance descriptor, the proposed descriptor lies in a relatively flat manifold, which can be treated as a Euclidean. This brings significant boost in the efficiency of the descriptor. The effectiveness and the generality of our approach is validated on two challenging vision tasks, pedestrian classification, and person reidentification. The experiments are carried out on multiple datasets achieving promising results.

The methodology for finding the same individual in a network of cameras must deal with significant changes in appearance caused by variations in illumination, viewing angle and a person's pose. Re-identification requires solving two fundamental problems: (1) determining a distance measure between features extracted from different cameras that copes with illumination changes (metric learning); and (2) ensuring that matched features refer to the same body part (correspondence). Most metric learning approaches focus on finding a robust distance measure between bounding box images, neglecting the alignment aspects. In this paper, we propose to learn appearance measures for patches that are combined using a spring model for addressing the correspondence problem. We validated our approach on the VIPeR, i-LIDS and CUHK01 datasets achieving new state of the art performance.

Histogram of Oriented Gradients is one of the most extensively used image descriptors in computer vision. It has successfully been applied to various vision tasks such as localization, classification and recognition. As it mainly captures gradient strengths in an image, it is sensitive to local variations in illumination and contrast. In the result, a normalization of this descriptor turns out to be essential for good performance [3, 4]. Although different normalization schemes have been investigated, all of them usually employ L1 or L2-norm. In this paper we show that an incautious application of L-like norms to the HOG descriptor might produce a hallucination effect. To overcome this issue, we propose a new normalization scheme that effectively minimizes hallucinations. This scheme is built upon a detailed analysis of the gradient distribution resulting in adding an extra bin with a specific value that increases HOG distinctiveness. We validated our approach on person re-identification and action recognition, demonstrating significant boost in the performance.

Re-identifying people in a network of cameras requires an invariant human representation. State of the art algorithms are likely to fail in real-world scenarios due to serious perspective changes. Most of existing approaches focus on invariant and discriminative features, while ignoring the body alignment issue. In this paper we propose 3 methods for improving the performance of person re-identification. We focus on eliminating perspective distortions by using 3D scene information. Perspective changes are minimized by affine transformations of cropped images containing the target (1). Further we estimate the human pose for (2) clustering data from a video stream and (3) weighting image features. The pose is estimated using 3D scene information and motion of the target. We validated our approach on a publicly available dataset with a network of 8 cameras. The results demonstrated significant increase in the re-identification performance over the state of the art.

This paper addresses a problem of recognizing human actions in video sequences. Recent studies have shown that methods which use bag-of-features and space-time features achieve high recognition accuracy. Such methods extract both appearance-based and motion-based features. This paper focuses only on appearance features. We propose to model relationships between different pixel-level appearance features such as intensity and gradient using Brownian covariance, which is a natural extension of classical covariance measure. While classical covariance can model only linear relationships, Brownian covariance models all kinds of possible relationships. We propose a method to compute Brownian covariance on space-time volume of a video sequence. We show that proposed Video Brownian Covariance (VBC) descriptor carries complementary information to the Histogram of Oriented Gradients (HOG) descriptor. The fusion of these two descriptors gives a significant improvement in performance on three challenging action recognition datasets.

This paper presents the methodology for the synthesis of real-time applications for the Infrastructure as a Service (IaaS) model of cloud computing.We assume that the function of the application is specified as a set of distributed echo algorithms with real-time constraints.Then our methodology schedules all tasks on available cloud infrastructure minimizing the total costs of the IaaS services, while satisfying all real-time requirements.It takes into account limited bandwidth of communication channels as well as the limited computation power of server nodes.The optimization is based on the iterative improvement algorithm, which has the capability of escaping from the local extrema, giving better results than greedy algorithms.The method starts from the fastest solution and in the next steps modifies the solution to reduce the cost of hiring the cloud infrastructure.We also present a sample application, that shows the benefits of using our methodology.

This paper introduces an image region descriptor and applies it to the problem of appearance matching. The proposed descriptor can be seen as a natural extension of covariance. Driven by recent studies in mathematical statistics related to Brownian motion, we design the Brownian descriptor. In contrast to the classical covariance descriptor, which measures the degree of linear relationship between features, our novel descriptor measures the degree of all kinds of possible relationships between features. We argue that the proposed covariance is a richer descriptor than the classical covariance, especially when fusing non-linearly dependent features. We evaluate our approach on tracking related applications, demonstrating that the Brownian descriptor outperforms the classical covariance in terms of matching accuracy and efficiency.

This paper presents a new approach for tracking multiple persons in a single camera. This approach focuses on recovering tracked individuals that have been lost and are detected again, after being miss-detected (e.g. occluded) or after leaving the scene and coming back. In order to correct tracking errors, a multi-cameras re-identification method is adapted, with a real-time constraint. The proposed approach uses a highly discriminative human signature based on covariance matrix, improved using background subtraction, and a people detection confidence. The problem of linking several tracklets belonging to the same individual is also handled as a ranking problem using a learned parameter. The objective is to create clusters of tracklets describing the same individual. The evaluation is performed on PETS2009 dataset showing promising results.

This paper addresses the problem of multi-target tracking in crowded scenes from a single camera. We propose an algorithm for learning discriminative appearance models for different targets. These appearance models are based on covariance descriptor extracted from tracklets given by a short-term tracking algorithm. Short-term tracking relies on object descriptors tuned by a controller which copes with context variation over time. We link tracklets by using discriminative analysis on a Riemannian manifold. Our evaluation shows that by applying this discriminative analysis, we can reduce false alarms and identity switches, not only for tracking in a single camera but also for matching object appearances between non-overlapping cameras.

Human re-identification is defined as a requirement to determine whether a given individual has already appeared over a network of cameras. This problem is particularly hard by significant appearance changes across different camera views. In order to re-identify people a human signature should handle difference in illumination, pose and camera parameters. We propose a new appearance model combining information from multiple images to obtain highly discriminative human signature, called Mean Riemannian Covariance Grid (MRCG). The method is evaluated and compared with the state of the art using benchmark video sequences from the ETHZ and the i-LIDS datasets. We demonstrate that the proposed approach outperforms state of the art methods. Finally, the results of our approach are shown on two other more pertinent datasets.

This paper presents a parallel branch-and-bound method to address the two-dimensional rectangular guillotine strip cutting problem. Our paper focuses on a parallel branching schema. We present a series of computational experiments to evaluate the strength of the approach. Optimal solutions have been found for some benchmark instances that had unknown solutions until now. For many other instances, we demonstrate that the proposed approach is time effective. The efficiency of the parallel version of the algorithm is compared and the speedup, when increasing the number of processors, is clearly demonstrated with an upper bound calculated by a specialised heuristic procedure.

In many surveillance systems there is a requirement to determine whether a given person of interest has already been observed over a network of cameras. This paper presents two approaches for this person re-identification problem. In general the human appearance obtained in one camera is usually different from the ones obtained in another camera. In order to re-identify people the human signature should handle difference in illumination, pose and camera parameters. Our appearance models are based on hoar-like features and dominant color descriptors. The AdaBoost scheme is applied to both descriptors to achieve the most invariant and discriminative signature. The methods are evaluated using benchmark video sequences with different camera views where people are automatically detected using Histograms of Oriented Gradients (HOG). The reidentification performance is presented using the cumulative matching characteristic (CMC) curve.

In many surveillance systems there is a requirement to determine whether a given person of interest has already been observed over a network of cameras. This is the person re-identification problem. The human appearance obtained in one camera is usually different from the ones obtained in another camera. In order to re-identify people the human signature should handle difference in illumination, pose and camera parameters. We propose a new appearance model based on spatial covariance regions extracted from human body parts. The new spatial pyramid scheme is applied to capture the correlation between human body parts in order to obtain a discriminative human signature. The human body parts are automatically detected using Histograms of Oriented Gradients (HOG). The method is evaluated using benchmark video sequences from i-LIDS Multiple-Camera Tracking Scenario data set. The re-identification performance is presented using the cumulative matching characteristic (CMC) curve. Finally, we show that the proposed approach outperforms state of the art methods.