94,589 research outputs found

    Digital Integral Cloaking

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    Toward the goal of achieving broadband and omnidirectional invisibility, we propose a method for practical invisibility cloaking. We call this “digital cloaking,” where space, angle, spectrum, and phase are discretized. Experimentally, we demonstrate a two-dimensional (2D) planar, ray optics, digital cloak by using lenticular lenses, similar to “integral imaging” for three-dimensional (3D) displays. Theoretically, this can be extended to a good approximation of an “ideal” 3D cloak. With continuing improvements in commercial digital technology, the resolution limitations of a digital cloak can be minimized

    Fast 2D to 3D conversion using a clustering-based hierarchical search in a machine learning framework

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    Automatic 2D-to-3D conversion is an important application for filling the gap between the increasing number of 3D displays and the still scant 3D content. However, existing approaches have an excessive computational cost that complicates its practical application. In this paper, a fast automatic 2D-to-3D conversion technique is proposed, which uses a machine learning framework to infer the 3D structure of a query color image from a training database with color and depth images. Assuming that photometrically similar images have analogous 3D structures, a depth map is estimated by searching the most similar color images in the database, and fusing the corresponding depth maps. Large databases are desirable to achieve better results, but the computational cost also increases. A clustering-based hierarchical search using compact SURF descriptors to characterize images is proposed to drastically reduce search times. A significant computational time improvement has been obtained regarding other state-of-the-art approaches, maintaining the quality results

    An Introduction to 3D User Interface Design

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    3D user interface design is a critical component of any virtual environment (VE) application. In this paper, we present a broad overview of three-dimensional (3D) interaction and user interfaces. We discuss the effect of common VE hardware devices on user interaction, as well as interaction techniques for generic 3D tasks and the use of traditional two-dimensional interaction styles in 3D environments. We divide most user interaction tasks into three categories: navigation, selection/manipulation, and system control. Throughout the paper, our focus is on presenting not only the available techniques, but also practical guidelines for 3D interaction design and widely held myths. Finally, we briefly discuss two approaches to 3D interaction design, and some example applications with complex 3D interaction requirements. We also present an annotated online bibliography as a reference companion to this article

    Evaluating methods for controlling depth perception in stereoscopic cinematography.

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    Existing stereoscopic imaging algorithms can create static stereoscopic images with perceived depth control function to ensure a compelling 3D viewing experience without visual discomfort. However, current algorithms do not normally support standard Cinematic Storytelling techniques. These techniques, such as object movement, camera motion, and zooming, can result in dynamic scene depth change within and between a series of frames (shots) in stereoscopic cinematography. In this study, we empirically evaluate the following three types of stereoscopic imaging approaches that aim to address this problem. (1) Real-Eye Configuration: set camera separation equal to the nominal human eye interpupillary distance. The perceived depth on the display is identical to the scene depth without any distortion. (2) Mapping Algorithm: map the scene depth to a predefined range on the display to avoid excessive perceived depth. A new method that dynamically adjusts the depth mapping from scene space to display space is presented in addition to an existing fixed depth mapping method. (3) Depth of Field Simulation: apply Depth of Field (DOF) blur effect to stereoscopic images. Only objects that are inside the DOF are viewed in full sharpness. Objects that are far away from the focus plane are blurred. We performed a human-based trial using the ITU-R BT.500-11 Recommendation to compare the depth quality of stereoscopic video sequences generated by the above-mentioned imaging methods. Our results indicate that viewers' practical 3D viewing volumes are different for individual stereoscopic displays and viewers can cope with much larger perceived depth range in viewing stereoscopic cinematography in comparison to static stereoscopic images. Our new dynamic depth mapping method does have an advantage over the fixed depth mapping method in controlling stereo depth perception. The DOF blur effect does not provide the expected improvement for perceived depth quality control in 3D cinematography. We anticipate the results will be of particular interest to 3D filmmaking and real time computer games

    Closing the chasm between virtual and physical delivery for innovative learning spaces using learning analytics

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    Purpose – One of the misconceptions of teaching and learning for practical-based programmes, such as engineering, sciences, architecture, design and arts, is the necessity to deliver via face-to-face physical modality. This paper refutes this claim by providing case studies of best practices in delivering such courses and their hands-on skillsets using completely online virtual delivery that utilises different formats of 2D and 3D media and tools, supported by evidence of efficiency using learning analytics. Design/methodology/approach – The case studies were designed using pedagogical principles of constructivism and deep learning, conducted within a mixture of 2D and 3D virtual learning environments with flexible interface and tools capabilities. State-of-the-art coding and scripting techniques were also used to automate different student tasks and increase engagement. Regression and descriptive analysis methods were used for Learning Analytics. Findings – Learning analytics of all case studies demonstrated the capability to achieve course/project learning outcomes, with high engagement from students amongst peers and with tutors. Furthermore, the diverse virtual learning tools used, allowed students to display creativity and innovation efficiently analogous to physical learning. Originality/value – The synthesis of utilised media and tools within this study displays innovation and originality in combining different technology techniques to achieve an effectual learning experience. That would usually necessitate face-to-face, hands-on physical contact to perform practical tasks and receive feedback on them. Furthermore, this paper provides suggestions for future research using more advanced technologies
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