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Multi-human tracking in the crowded environment is a challenging problem due to occlusions, pose change, viewpoint variation and cluttered background. In this work, we propose a robust feature learning for tracking-by-detection methods based on second-order attention network that can capture higher-order relationships between salient features at the early stages of Convolutional Neural Network (CNN). Guided Second-Order Attention Network (GSAN) that, unlike the existing attention learning methods which are weakly-supervised, uses a supervisory signal based on the quality of the self-learned attention maps. More specifically, GSAN looks into the attended maps of a person having the highest confidence and supervise itself to look into the correct regions in the images of the person. Attention maps learned this way are spatially aligned and thus robust to camera-view changes and body pose variations. We verify the effectiveness of our approach by comparing with the state-of-the-art methods on challenging person re-identification and multi object tracking (MOT) datasets.

In recent years, an attempt is being made to control robots more intuitive and intelligible by exploiting and integrating anthropomorphic features to boost social human-robot interaction. The design and construction of anthropomorphic robots for this kind of interaction is not the only challenging issue -- smooth and expectation-matching motion control is still an unsolved topic. In this work we present a highly configurable, portable, and open control framework that facilitates anthropomorphic motion generation for humanoid robot heads by enhancing state-of-the-art neck-eye coordination with human-like eyelid saccades and animation. On top of that, the presented framework supports dynamic neck offset angles that allow animation overlays and changes in alignment to the robots communication partner whileretaining visual focus on a given target. In order to demonstrate the universal applicability of the proposed ideas we used this framework to control the Flobi and the iCub robot head, both in simulation and on the physical robot. In order to foster further comparative studies of different robot heads, we will release all software, based on this contribution, under an open-source license.

This paper presents an approach to guide a robot arm visually, by using an active stereo camera mounted on an active head platform. The camera and head system is capable of changing the look-direction and fixating on the target object. Unlike the traditional AI approach, the proposed approach does not require full perspective camera calibration or scene reconstruction. Visual parameters which contain relationships with the robot or world space are used instead of the reconstructed three-dimensional (3D) world information. The necessary visual cues required to control the robot are developed. These visual cues are computed solely from the image coordinates. The relationship between these visual cues and the robot space is then established via a mapping matrix. Using this relation together with visual feedback, the end-effector can be guided towards the target object. Even though the 3D world coordinates are not recovered, the positioning accuracy attainable is high. To allow for vergence movement of the stereo camera or pan–tilt movements of the head platform, methods to compensate the mapping matrix are proposed. This approach eliminates the need for re-calibration after any deliberate change in the configuration of the head platform. Therefore, building an autonomous robot with coordinated head, eye and hand becomes technically feasible. Simulation studies on the capability of the system to reach arbitrary target objects are presented. High flexibility and large accessible workspace are the main advantages of the proposed autonomous robot system.

Over the last decade, automated analysis of human affective behavior has become an active research area in computer science, psychology, neuroscience, and related fields. This study investigates the application of Gabor filter based features in combination of Genetic Algorithm (GA) and Support Vector Machine (SVM) for dynamic analysis of six basic facial expressions from video sequences. Traditionally, a set of Gabor filters is used for feature extraction from static images of face. However, we employed Sum of Difference (SOD) approach to analysis the dynamics of facial expression from a video sequence. We also used GA to overcome the problem of high dimensional feature vectors and computation cost. A local Gabor filter bank with selected frequencies and orientations is produced by GA. The experimental results show that the proposed method is effective for temporal analysis of affective states. The detection rate of six basic emotions has been reached to 92.97% for Cohn-Kanade (CK+) database. ASTAR (Agency for Sci., Tech. and Research, S’pore) Accepted version

In recent decades, automatic fingerprint identification system has attracted significant interest among the scientific research community. Though large amount of effort has been made in both the academic and industrial communities, there are still unsolved problems. Noisy image processing and large scale database processing are two typical problems. Fingerprint images consist of oriented texture. Therefore the orientation information plays a very important role in fingerprint processing. Moreover, the orientation of the fingerprint follows a certain structure that is not random. Such oriented structure provides a possibility to recover the orientation information in fingerprints corrupted by noise, even for a large noise patch which cannot be solved by the traditional gradient based methods. Accurate reconstruction of the orientations is useful for fingerprint filtering, segmentation, classification and recognition. Several methods have been proposed to reconstruct the fingerprint orientation. In this thesis, phase portrait model approach is used. The first order phase portrait is demonstrated to be robust for both occluded and noisy fingerprints. It also has the capability to describe the orientation patterns of the core point and delta point in a fingerprint image. Therefore a method based on the first order phase portrait is proposed to reconstruct the local orientation near the core and delta points. Furthermore, considering the regularity of the fingerprint orientation and linearity of the first order phase portrait, a model based on the piecewise phase portrait is used to predict the orientations far away from the singular point region. The advantage of this prediction model is that it provides a way to overcome the large patch of noise or missing orientation. To obtain the fingerprint orientation with higher precision, more complicated model based on the constrained nonlinear phase portrait approach is proposed. The model employs the advantages of both the first order and high order phase portrait model. Hence accurate reconstructed orientations at both the local and global area can be obtained simultaneously. This thesis also addresses fingerprint classification using the coefficients of the constrained nonlinear phase portrait model together with the singularities information. Since the coefficients of the constrained nonlinear phase portrait model play a key role in reconstructing the fingerprint orientation, it is also expected to be able to effectively classify fingerprints. A fingerprint classification algorithm using the orientation model and the singular points' information which complement the orientation information is developed and is shown to have good classification performance. DOCTOR OF PHILOSOPHY (EEE)