Freehand 3D Scanning in a Mobile Environment using Video

This work is motivated by two important trends in consumer computing: (i) the growing pervasiveness of mobile computing devices, and (ii) the users’ desire for increasingly complex but readily acquired and manipulated information content. Specifically, we develop and describe a system for 3D model creation of an object, using only a standard mobile device such as a smart phone. Our approach applies the structured light projection methodology and exploits multiple image input such as frames from a video sequence. In comparison with previous work, a significant further challenge addressed here is that of lower quality input data and limited hardware (processing power and memory, camera and projector quality). Novelties include: (i) a comparison of projection pattern detection approaches in the context of a mobile environment – a robust method combining colour detection and a phase congruency descriptor is evaluated, (ii) a model for single view reconstruction which exploits epipolar, coplanarity and topological constraints, (iii) the use of mobile device sensor data in the iterative closest point algorithm used to register multiple partial 3D reconstructions, and (iv) two heuristics for determining the order in which buffered single view based reconstructions are merged. Our experiments demonstrate that visually appealing results are obtained in a speedy manner which does not require specialist knowledge or expertise from the user.

A pose-wise linear illumination manifold model for face recognition using video

The objective of this work is to recognize faces using video sequences both for training and novel input, in a realistic, unconstrained setup in which lighting, pose and user motion pattern have a wide variability and face images are of low resolution. There are three major areas of novelty: (i) illumination generalization is achieved by combining coarse histogram correction with fine illumination manifold-based normalization; (ii) pose robustness is achieved by decomposing each appearance manifold into semantic Gaussian pose clusters, comparing the corresponding clusters and fusing the results using an RBF network; (iii) a fully automatic recognition system based on the proposed method is described and extensively evaluated on 600 head motion video sequences with extreme illumination, pose and motion pattern variation. On this challenging data set our system consistently demonstrated a very high recognition rate (95% on average), significantly outperforming state-of-the-art methods from the literature.

An illumination invariant face recognition system for access control using video

Illumination and pose invariance are the most challenging aspects of face recognition. In this paper we describe a fully automatic face recognition system that uses video information to achieve illumination and pose robustness. In the proposed method, highly nonlinear manifolds of face motion are approximated using three Gaussian pose clusters. Pose robustness is achieved by comparing the corresponding pose clusters and probabilistically combining the results to derive a measure of similarity between two manifolds. Illumination is normalized on a per-pose basis. Region-based gamma intensity correction is used to correct for coarse illumination changes, while further refinement is achieved by combining a learnt linear manifold of illumination variation with constraints on face pattern distribution, derived from video. Comparative experimental evaluation is presented and the proposed method is shown to greatly outperform state-of-the-art algorithms. Consistent recognition rates of 94-100% are achieved across dramatic changes in illumination.

Structural understanding from note-taking within video lectures

 Note-taking during all kinds of lectures is a standard and easy technique for learners of all ages to self-document their thought during learning. Based on a metacognitive rationale, this study investigates the effect of note-taking within different kinds of video-lectures – text-driven presentations versus graphical presentations. The availability of note-taking is experimentally controlled for 54 undergraduate students, and the quality of the nodes is then projected to the learning outcome as compared to the content of the lectures. Our results indicate little direct impact of the note quality, and contra-intuitively, not taking notes helped learners with their knowledge structure. Our study helps to understand the limits of note-taking during learning and with a broader theoretical understanding of idiosyncratic externalization.

Using online video-recorded interviews to connect the theory and practice of inclusive education in a course for student teachers

This article reports on a study into university preservice teachers’ perceptions of online video-recorded interviews as an alternative to the traditional lecture format in a course on inclusive education. With the aim of assisting preservice teachers to link theory and practice, the series of video-recorded interviews focused on key concepts around educating students with diverse needs and abilities. The interviews were conducted between the course coordinator and a number of professionals with relevant field experience in special education and inclusion, and were then made available to preservice teachers online. Survey data indicated that this type of delivery model was perceived as effective in promoting engagement and learning, and in facilitating an understanding of the connection between theory and practice. Implications for teacher education are discussed.

The man who mistook Marat for Sade: 'living' memory and the video archive

Digital video archives, which are growing at an exponential rate, will become increasingly important to Theatre History and Performance Studies, and questions of how scholars negotiate the relationships between memory, technology and performance events in theoretical and practical terms will become crucial. Indeed, there is already a considerable body of scholarly material on this topic. This article considers these questions with specific reference to the relationship between video records deposited in digital archives and human memory. First and foremost, this article raises questions about the authority of the archive and the ways in which archival technologies, in the words of Maaike Bleeker, 'transform how we remember, how our and others' memories are entangled in the here-and-now, and, in the end, even how we think and imagine'.