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This study evaluated the effects of reading text on an optical see-through head-mounted display during treadmill walking in a virtual environment. Thirty participants were recruited to perform Chinese reading tasks by reading six types of text layouts in two polarity settings. A virtual environment was displayed on a projection screen to simulate a walking situation in which obstacles were encountered. High- and low-density obstacles were applied. Objective measures included reading performance, gait variability, and the error count of obstacles. The subjective measures were the situational awareness rating technique (SART) and NASA-Task Load Index (NASA-TLX) scores. The results indicated that font size and polarity affected the gait variability, reading performance, situational awareness, and mental workload ratings. The obstacle density affects gait variability and situation awareness rating. The layout with 32-point text and positive polarity yielded faster reading speed, better subjective ratings, and less variability in minimum foot clearance. [ABSTRACT FROM AUTHOR]

In view of the matching problem between objects and mirrors in images, the RNFA(Relative Number of False Alarms)edge chain detection method is introduced to obtain richer line segments. An improved LBD(Line Band Descriptor) algorithm is proposed for constructing local invariant feature descriptors, and initial matching pairs are obtained by comparing local invariant feature descriptors. The screening of the global projection angle is adopted and the false matches in the initial matching pairs are eliminated fitting the projection center line. After the selection of the global projection angle and the fitting of the projection median are completed, the screening of the local invariant feature descriptor threshold is relaxed to obtain more matching pairs and improve the recall rate. The experimental results of image set simulation show that the designed algorithm can better identify line segments in the weaker texture regions and obtain more matching pairs on the basis of the guaranteed performance of the original algorithm, which can improve the correct matching rate by about 5% and achieve a recall rate of over 90%. [ABSTRACT FROM AUTHOR]

Background: Add-on devices with projections, e.g., Endocuff, Endocuff Vision, EndoRings, and Wingcap, placed on the distal tip of the colonoscope promise to improve the detection of precancerous lesions. We performed a meta-analysis to evaluate the performance of these devices exclusively among individuals undergoing colonoscopy for screening purpose. Methods: A computerized literature search was performed across MEDLINE and Cochrane Library databases for randomized controlled trials that compared standard colonoscopy (SC) to procedures using add-on devices. The primary outcome was adenoma detection rate (ADR), while secondary outcomes included polyp detection rate (PDR), advanced ADR (AADR), and sessile serrated lesion detection rate (SSLDR). The effect size on study outcomes was calculated using a random-effects model and presented as the risk ratio (RR) and 95% confidence interval (CI). Results: Seven studies enrolling a total of 5785 patients were included. The use of add-on-devices with projections was associated with a higher ADR compared to SC: 45.9% vs. 41.1%; RR 1.18, 95%CI 1.02-1.37; P=0.03; χ2=79%. Although PDR was higher in screening colonoscopies assisted by add-on devices as compared to SC, the difference failed to reach significance: 55.1% vs. 50.8%; RR 1.10, 95%CI 0.96-1.26; P=0.17; χ2=75%. No difference was found between procedures assisted by add-on devices with projections and SC colonoscopies in terms of AADR (18.5% vs. 17.6%; RR 1.00, 95%CI 0.79-1.27; P=0.98; χ2=56%) or SSLDR (6.8% vs. 5.8%; RR 1.17, 95%CI 0.95-1.44; P=0.15; I2=0%). Conclusion: Colonoscopy assisted by add-on devices with projections achieves a better ADR compared to SC among individuals undergoing screening for bowel cancer. [ABSTRACT FROM AUTHOR]

The fact that the Nazis looked to the United States for inspiration has led some to claim that the US served Nazi thinkers as a "model." This article argues instead that Nazis looked to America as a countermodel for how not to deal with the "Jewish question." Through an intertextual analysis of visual and textual primary sources, this article demonstrates how the Nazis used America as a projection screen for developing their vision of empire and "redemptive antisemitism." The Nazis admired the United States' racist laws and technological development but despised Americans for ignoring the "Jewish threat." By showing how the Nazis used the United States as a mirror for developing Nazi ideology, this article reintroduces the category of antisemitic ideology to the Historikerstreit 2.0 debate. [ABSTRACT FROM AUTHOR]

Are leaders made or born? Leader–follower roles have been well characterized in social science, but they remain somewhat obscure in sensory-motor coordination. Furthermore, it is unknown how and why leader–follower relationships are acquired, including innate versus acquired controversies. We developed a novel asymmetrical coordination task in which two participants (dyad) need to collaborate in transporting a simulated beam while maintaining its horizontal attitude. This experimental paradigm was implemented by twin robotic manipulanda, simulated beam dynamics, haptic interactions, and a projection screen. Clear leader–follower relationships were learned only when strong haptic feedback was introduced. This phenomenon occurred despite participants not being informed that they were interacting with each other and the large number of equally-valid alternative dyadic coordination strategies. We demonstrate the emergence of consistent leader–follower relationships in sensory-motor coordination, and further show that haptic interaction is essential for dyadic co-adaptation. These results provide insights into neural mechanisms responsible for the formation of leader–follower relationships in our society. [ABSTRACT FROM AUTHOR]

The videoscenic play is a hybrid product that presents a fictional world meaned through theatrical and audiovisual media from two different modes of representation, the narrative of enunciation audiovisual and the dramatic one. This research aims to discover how it works. To do this, it uses a methodology that relates the Internal Reference Field of the text and the External Reference Field. It is pointed to the projection screen, material support of audiovisual representation, as an interface between media and modes of representation, allowing the access of the theatrical character to the audiovisual universe and activating the viewer's participation in the construction of meaning, since it shares with the own text the levels of production and reception of the culture of the image in which it is immersed. [ABSTRACT FROM AUTHOR]

The article presents a history of literary discussion on vertical filmmaking and vertical projections. Topics discussed include the existence of vertical filmmaking in artistic contexts throughout the 20th century, the academic discussion on vertical framing in debates that began in the 21st century, factors that influenced vertical narrative themes in horizontally framed movies, and the suppression on vertical formats from commercial cinema.

A non-coaxial optical screen based projection 3D display with extended viewing distance range is proposed. The proposed 3D display is composed of a projector array and a non-coaxial optical screen constructed with a series of one-dimensional retro-reflective components (1DRRCs). The projector array projects parallax images onto the screen, then the non-coaxial optical screen converges light to linearly shaped region which pass through the position of the projector and forms a view area by one-dimensional retro-reflection. At each view area, different parallax images corresponding to the projectors can be observed respectively, therefore 3D display is formed. In the proposed 3D display, the optical axis of each 1DRRC shares a common direction and isn't parallel to the normal of the non-coaxial optical screen plane. Consequently, reflected light converges into a linearly shaped region. This linearly shaped region isn't parallel to the non-coaxial optical screen, so that it can cover a extended range from back to front and lead to larger viewing distance range. A prototype is developed to verify the principle. In the prototype, the viewing distance range covers a range of 959–2083 mm, then demonstrating the proposed 3D display agree well with the theory. • Non-coaxial optical screen based projection 3D display can extend viewing distance range. • The optical axis of non-coaxial optical screen isn't parallel to the screen plane. • Non-coaxial optical screens converges light to a linearly shaped region by one-dimensional retro-reflection. • Developed a prototype with a viewing distance range of 959–2083 mm. [ABSTRACT FROM AUTHOR]

Geometric and hidden projection are two important properties to consider for three-level fractional factorials. The effective development of methods that can address tasks involving both these properties requires a unified design framework that integrates them. We highlight one integrative framework that is based on indicator functions for three-level designs under the linear-quadratic parameterization system. We demonstrate the broad scope and utility of this framework by using it to develop a new procedure for addressing a task comprised of three serial problems in geometric and hidden projection. The first in the series is to construct the sets of smallest follow-up runs to a projection of a three-level design that yield specified aliasing relations. Second is to immediately characterize the partial aliasing relations among factorial effects in the resulting augmented designs. The final problem is to identify the augmented designs that maximize popular optimality criteria with respect to the second-order model among all of the candidate augmentations. The application of our procedure is illustrated with sample projections of definitive screening designs onto four, five, and six factors. The integrative framework that we present can ultimately facilitate the systematic development of methods that advance comprehensive understanding of multiple properties for general three-level designs. • Based on indicator functions under the linear-quadratic parameterization system. • Identifies optimum minimum-run augmentations with no aliasing among select effects. • Characterizes partial aliasing relations among factorial effects in augmented designs. • Facilitates systematic development of new methods for general three-level designs. [ABSTRACT FROM AUTHOR]

In the initial stages of experimentation, many factors are examined for a possible significant influence on the response of interest. After such screening, the design used is projected into the significant factors and further evaluation of their effects is performed using the projection design. It is therefore interesting to evaluate the projection properties of screening designs since such an evaluation is extremely useful in selecting the best design for experimentation. In this paper, we examine two-level supersaturated screening designs that are constructed following Lin's method. Some theoretical results are given and a detailed evaluation of supersaturated designs with up to 12 runs is performed. [ABSTRACT FROM AUTHOR]

In this article the author explores the idea that, owing to their shared three-dimensional nature, holophons and virtual holograms are well suited as mediums for visual music composition. This union is ripe with creative opportunity and fraught with challenges in the areas of aesthetics and technical implementation. Squarely situated upon the bleeding edge of phenomenological research and creative practice, this novel medium is within reach. Here, one methodological pipeline is delineated that employs the convergence of holophony, virtual holography and supercomputing toward the creation of visual music compositions intended for head-mounted displays or large-scale 3D/360-degree projection screens and high-density loudspeaker arrays. [ABSTRACT FROM AUTHOR]

A new architecture for a thin (2‐cm depth) rear projection display is described. In order to achieve this small depth, a very high density of rear projectors is used. Three prototype displays using rear projectors on both 5‐ and 2‐cm pitch arrays are described. The displays can achieve an effective screen pixel pitch of as small as 0.5 mm, which makes this technology competitive in terms of resolution with fine pitch LED displays; however, orders of magnitude fewer LEDs are required: Each rear projector requires only one white LED and a color liquid crystal light modulator. In the three prototypes, the projector light modulators utilize 101‐cm (40 in.), 80‐cm (31.5 in.), and 60‐cm (24 in.) diagonal liquid crystal display glass. To minimize cost, no lenses are utilized for the rear projectors. An RGB LED array may augment the projector array, which provides a low resolution component of the image onto which the high resolution component is superimposed by the projector array. Edge gaps between active areas on adjacent LCD glass units are completely eliminated by the rear projection approach enabling low profile wall‐size seamless displays. Display contrast depends on rear projection screen design. [ABSTRACT FROM AUTHOR]

Electrohydrodynamic instability in liquid crystals is investigated for smart window applications. By comparing different species of ions doped in liquid crystals, the positive charge of the organic part of the salt is the origin of the generation of vortexes and leads to the activation of electrohydrodynamic instability. By replacing conventional electrolytes with zwitterions, compared to electrolyte-doped liquid crystals, zwitterion-doped liquid crystals have a broader range of optimal frequency from 10 Hz to 5 kHz. The devices can be switched between the transparent state and the light scattering state for thousands of times without showing any fatigue. A scattering colour is obtained by incorporating a dichroic dye in zwitterion-doped liquid crystal. A patterned device is designed and shows a localised light scattering and colour effect in the presence of an electric field. This strategy will make electrohydrodynamic instability possible to enrich the applications across smart windows, projection screens and information displays. [ABSTRACT FROM AUTHOR]

We consider feature screening for ultrahigh dimensional additive model with multivariate response in this paper. A new method named generalized correlation based projection screening is proposed by using generalized correlation between each predictor and multivariate response. The sure screening and ranking consistency properties are established under some regularized conditions for the proposed procedure. In addition, we construct an iterative version of the proposed screening procedure to enhance the finite sample screening performance. Both simulation studies and the real data analysis demonstrate that the proposed method works effectively. [ABSTRACT FROM AUTHOR]

Abstract–Definitive screening designs permit the study of many quantitative factors in a few runs more than twice the number of factors. In practical applications, researchers often require a design for m quantitative factors, construct a definitive screening design for more than m factors and drop the superfluous columns. This is done when the number of runs in the standard m-factor definitive screening design is considered too limited or when no standard definitive screening design (sDSD) exists for m factors. In these cases, it is common practice to arbitrarily drop the last columns of the larger design. In this article, we show that certain statistical properties of the resulting experimental design depend on the exact columns dropped and that other properties are insensitive to these columns. We perform a complete search for the best sets of 1–8 columns to drop from sDSDs with up to 24 factors. We observed the largest differences in statistical properties when dropping four columns from 8- and 10-factor definitive screening designs. In other cases, the differences are small, or even nonexistent. [ABSTRACT FROM AUTHOR]

Ordinary projection screen is not sensitive to interaction, it cannot meet the demands of teaching, virtual reality, and other applications. Due to the fact that people always use hands to complete a variety of human–computer interaction, the finger-based interactive projection technology is worth being researched. In this paper, an ordinary monocular camera is used to acquire video frame on projection screen, and the touch signal of finger in frame is used as the input of interactive projection system. Because the differences between spatial frequency of common digital camera and the projection screen is small, the frame obtained from camera will contain moire fringe, which needs to be filtered in image frequency domain. Then the difference between current frame edge and previous frame edge is calculated to obtain moving object edge clues. According to these clues, the most possible contour curve is searched in current frame edge, and the curve is fitted by polynomial approximation method. Its curvature integration is used to match with the curvature integration of finger template curve. After that the fingers in the curve are recognized. Because color information is not needed, this method can be used to recognize gloved fingers. Finally, finger shadow is used to judge whether the finger touches projection screen to complete interactive process. The experiments of writing and collaboratively rotating picture on projector screen show that this method can effectively complete interactive operation with the projection screen and can realize the multi-user operation. [ABSTRACT FROM AUTHOR]

A planetarium is an invaluable tool for teaching introductory astronomy, but one that few astronomy educators have ready access to. Here we describe a do-it-yourself planetarium that can be built with modest funding. There have been other planetarium construction projects described in the literature and online, most of which use cardboard to make multiple faces, which are then fastened together to form a dome that serves as the planetarium projection surface. Our design uses a skeletal dome that supports a hemispherical cloth projection screen. A computer LCD projector, reflecting off a diverging half-dome security mirror on the interior edge of the dome base, serves as the starfield projector. The open-source sky simulation software Stellarium has the necessary features to pre-distort the sky image appropriately so that, after reflection from the diverging mirror, the dome is properly filled. [ABSTRACT FROM AUTHOR]

The early stages of many real-life experiments involve a large number of factors among which only a few factors are active. Unfortunately, the optimal full-dimensional designs of those early stages may have bad low-dimensional projections and the experimenters do not know which factors turn out to be important before conducting the experiment. Therefore, designs with good projections are desirable for factor screening. In this regard, significant questions are arising such as whether the optimal full-dimensional designs have good projections onto low dimensions? How experimenters can measure the goodness of a full-dimensional design by focusing on all of its projections?, and are there linkages between the optimality of a full-dimensional design and the optimality of its projections? Through theoretical justifications, this paper tries to provide answers to these interesting questions by investigating the construction of optimal (average) projection designs for screening either nominal or quantitative factors. The main results show that: based on the aberration and orthogonality criteria the full-dimensional design is optimal if and only if it is optimal projection design; the full-dimensional design is optimal via the aberration and orthogonality if and only if it is uniform projection design; there is no guarantee that a uniform full-dimensional design is optimal projection design via any criterion; the projection design is optimal via the aberration, orthogonality and uniformity criteria if it is optimal via any criterion of them; and the saturated orthogonal designs have the same average projection performance. [ABSTRACT FROM AUTHOR]

We devised and developed functional projection screen for personal use, small meetings, car pillars, and near‐eye projection. The screen deflects incident light from a projector by a fixed angle θview and diffuses in a certain angular range Δθview. We have realized the screen by modifying the fine structures based on the corner cube reflector (CCR) and reported basic concept and optical characteristics at IDW2017 and SID2018. However, there remained issues of light in unnecessary direction and insufficient uniformity of the diffused light. In this paper, we report on further modification of the fine structures by optimizing the inclination angles of three curved surfaces of the CCR that result in change of the diffused light pattern. Consequently, the modifications of the deflection angle θview and the diffusion angle Δθview resulted in significant improvement in the screen characteristics. These new results were applied to the screen for personal use and car pillar applications. [ABSTRACT FROM AUTHOR]

This essay examines the bedsheet as a historic screen technology while tracing the cultural discourses that emerge from and around the bedsheet as both a cinematic and cultural object. The history of the bedsheet screen reveals origin stories of moving-image exhibition and illuminates the entwined histories of US cinema and race. In its examination of the sheet-screen across a range of moving-image practices and representations in popular and industry discourse, this essay foregrounds the materiality of the screen and its relationship to nontheatrical exhibition sites, segregationist practices, and the social significance of the screen. [ABSTRACT FROM AUTHOR]

The production of curved displays has substantially increased in the past years. This new type of displays can enhance the feeling of immersion by surrounding the viewers with content. In this paper, we propose a content-aware and depth-aware video deformation method for projection of rectangular content on curved displays. Novel deformation and grid-based mapping methods are proposed to prevent over-preservation of foreground content for static and dynamic content and to enforce temporal coherence. The objective evaluation of the results shows that our approach efficiently and consistently preserves both static and dynamic content. A thorough subjective evaluation is also performed using a real-world curved screen as well as a virtual reality setup, showcasing our method against existing methods. Experimental results indicate that our method systematically outperforms the existing state-of-the-art, providing minimal content distortion and high temporal coherence between consecutive frames. • We introduce a content-aware and depth-aware video deformation method for projection of rectangular content on curved displays. • Both subjective and objective evaluation validates our method over state of the art algorithms, especially for Consistent Video Projection on the Curved Displays. [ABSTRACT FROM AUTHOR]

This paper analyzes how the rock band U2 uses screens as central components of the experiences of their concerts. Examining moments from throughout their career, and emphasizing their recent 'Innocence and Experience' and 'Experience and Innocence' tours, this article argues that U2's constant employment of technology is less about spectacle, and more about the constitution of 'mediated environments' that reflect and embody how people live in and through all manner of media, including screens. Drawing on conceptions of U2 as a band interested in problem-solving and innovation, I position their on-going engagements with technology as a processual search for ways to live productively alongside technology. I use media studies frameworks to argue U2 expresses a politics of ambivalence through their use of screens, one that cannot resolve the tensions between the communicative power of technology and its potential to erode social relationships. However, this politics of ambivalence - as expressed through their tours - is productive, in that it produces for attendees ways of thinking and interacting with screen technologies.Keywords: screens, mediation, technology, ambivalence, U2 [ABSTRACT FROM AUTHOR]

In recent years, many scientific and industrial centres in the world developed virtual reality systems or laboratories. At present, among the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems usually consist of four, five, or six projection screens arranged in the form of a closed or hemi-closed space. The basic task of such systems is to ensure the effect of user "immersion" in the surrounding environment. The effect of user "immersion" into virtual reality in such systems is largely dependent on optical properties of the system, especially on quality of projection of three-dimensional images. In this paper, techniques of projection of three-dimensional (3D) images in CAVE-type virtual reality systems are analysed. The requirements of these techniques for such virtual reality systems are outlined. Based on the results of measurements performed in a unique CAVE-type virtual reality laboratory equipped with two different 3D projection techniques, named Immersive 3D Visualization Lab (I3DVL), that was recently opened at the Gdańsk University of Technology, the stereoscopic parameters and colour gamut of Infitec and Active Stereo stereoscopic projection techniques are examined and discussed. The obtained results enable to estimate the projection system quality for application in CAVE-type virtual reality installations. [ABSTRACT FROM AUTHOR]

The aim of this paper is to elucidate how occupants perceive their lit environments in a university setting and how they interact with lighting controls using qualitative methods. Semi-structured interviews were carried out with academic teaching and research staff. Thematic analysis identified four main themes: control and choice, connection with the outdoors, concentration and comfort. Participants were largely able to control and adapt their lighting using small power lighting in office spaces and they perceived this as beneficial to comfort and concentration. Participants expressed frustration with the light switches in classrooms, and a lack of consistency in lighting controls across the university buildings was particularly notable. Installers should consider how piecemeal upgrades on large estates affect the perception of buildings where occupiers face multiple control systems. The management of the lighting in classroom spaces including the type and location of blinds, lack of regular window cleaning in some buildings and difficulty in minimising light on projection screens in upgraded classrooms were cited as areas for improvement. Wider implications for lighting control and management highlighted by this study include most notably that a lack of end users consultation has serious consequences on their perception of lighting upgrades and their willingness to employ ‘workarounds.’ [ABSTRACT FROM AUTHOR]

Abstract: We devised and developed a novel directive projection screen for applications such as personal use, small group meeting, automotive pillar, and near‐eye. This screen reflects diffused light at an angle Δθview around a direction deviated by θview from the direction of the projector. By applying this screen to automobiles, for example, by installing a projector at a position slightly shifted from the driver, it is possible to reflect the projected light with high efficiency to a certain range around the face of driver. To realize such a characteristic, a hollow corner cube retroreflector (CCR) was modified as follows. The bottom surface of the CCR was tilted by θview/2 to change the direction of the reflected light by θview from the retroreflection direction. In addition, three sides' surfaces of the CCR were curved, so that the light to be diffused within a designed angle (θview ± Δθview/2). The novel retroreflector CCR (D‐CCR) has a single divergent surface with a three‐sided curved surface. We fabricated a prototype with θview = 10° and Δθview = 16° (i.e., the viewing angle for a single D‐CCR, 10° ± 8°), simulated, and measured its optical properties. We closely confirmed the desired characteristics in which an optical gain of 16 was obtained. [ABSTRACT FROM AUTHOR]

A free-form projection screen is designed for an off-axis visual display, which shows great potential in applications such as flight training for providing both accommodation and convergence cues for pilots. The method based on point cloud is proposed for the design of the free-form surface, and the design of the point cloud is controlled by a program written in the macro-language. In the visual display based on the free-form projection screen, when the error of the screen alongZ-axis is 1 mm, the error of visual distance at each filed is less than 1%. And the resolution of the design for full field is better than 1′, which meet the requirement of resolution for human eyes. [ABSTRACT FROM AUTHOR]

This paper proposes an accurate glasses detection algorithm for in-plane rotated faces. Firstly, to normalize the face with in-plane rotation to be an upright one, this paper proposes a new set of ±26.565° haar-like features which can be calculated quickly to represent the features of rotated faces. With these new features, we address to build different rotated detectors by rotating upright face detector directly so as to achieve in-plane rotated face detection. Secondly, according to the rule that the objects with fixed and complex structure in a simple background are much easily to be detected, as the eyes have much complex structure in the face, we propose to detect the eyes for minimizing the glasses searching region. Because the nosepiece region of the glasses has much fixed structure and simple background, we use this part to train a new detector with the haar-like features and AdaBoost algorithm for precise glasses detection. This approach accomplishes glasses detection for in-plane rotated face with high speed and precision. The experimental results on the CMU-MIT, BioID, and CAS-PEAL-R1 face databases demonstrate that the algorithms for face, eye and glasses detection yield accurate results and maintain the speed advantage. [ABSTRACT FROM AUTHOR]

Illusory self-motion (vection) can be generated by visual stimulation. The purpose of the present study was to compare behavioral vection measures including intensity ratings, duration, and onset time across different visual display types. Participants were exposed to a pattern of alternating black-and-white horizontal or vertical bars that moved either in vertical or horizontal direction, respectively. Stimuli were presented on four types of displays in randomized order: (a) large field of view dome projection, (b) combination of three computer screens, (c) single computer screen, (d) large field of view flat projection screen. A Computer Rod and Frame Test was used to measure field dependence, a cognitive style indicating the person's tendency to rely on external cues (i.e., field dependent) or internal cues (i.e., field independent) with respect to the perception of one's body position in space. Results revealed that all four displays successfully generated at least moderately strong vection. However, shortest vection onset, longest vection duration, and strongest vection intensity showed for the dome projection and the combination of three screens. This effect was further pronounced in field independent participants, indicating that field dependence can alter vection. [ABSTRACT FROM AUTHOR]

When a digital projector is applied in high precision applications, the intrinsic parameters and distortion characteristics should be calibrated precisely. In this paper, a flexible full-field projector calibration method is proposed without any approximate distortion model. With planar homography theory and fringe projection technique, the projector distortion characteristic on each pixel can be measured independently and an initial distortion map is generated. The intrinsic parameters are calibrated afterwards. Then, the initial distortion map can be refined by correcting the non-perpendicularity between the optical axis and image plane. The original pattern to be projected is corrected with the refined distortion map. Thus, the calibrated projector can be regarded as an ideal projector conforming to the pinhole model. Experimental results show a nearly ideal residual map for the corrected projection pattern. In addition, the proposed calibration method is flexible without any sophisticated ancillary equipment or complicated procedure. [ABSTRACT FROM AUTHOR]

The modern viewer is familiar with the cinematic paradigm, in which he or she is fixed in a darkened auditorium. However, current audio-visual technologies introduce new viewing modes. This article explores the spatial properties of the projection system (projector, screen surface, projection beam and the viewer), during the transition from analogue to digital technology, with paradigms from the 1960s’ expanded cinema to current multimedia installations, in particular works defined as digitally expanded cinema. Our aim is to explore how the projection space can be combined with architectural space, using expanded cinema design principles. [ABSTRACT FROM PUBLISHER]

In video surveillance application, in order to deploy the cameras effectively, we need to know the information of the monitored scene, including the position, shape and location of the obstacle in the scene. Also, the area where the target appears frequently. Aiming at the complex structure and difficult modeling of the scene, a scene obstacle model construction method based on moving target tracking is proposed. The scene observation model can be obtained by using the spatial projection relationship to determine the position of the obstacle and interesting area. This method only needs to track the target motion, and does not need to reconstruct the 3D structure and image mosaic, which can effectively solve the online adaptive modeling of the scene. [ABSTRACT FROM AUTHOR]

Flat surfaces in our living environment to be used as replacements of a projection screen are not necessarily white. We propose a perceptual radiometric compensation method to counteract the effect of color projection surfaces on image appearance. It reduces color clipping while preserving the hue and brightness of images based on the anchoring property of human visual system. In addition, it considers the effect of chromatic adaptation on perceptual image quality and fixes the color distortion caused by non-white projection surfaces by properly shifting the color of the image pixels toward the complementary color of the projection surface. User ratings show that our method outperforms the existing methods in 974 out of 1020 subjective tests. [ABSTRACT FROM PUBLISHER]

A novel adaptive filter combining the affine projection algorithm (APA) and the affine projection sign algorithm (APSA) is proposed using an impulsive noise indicator. This indicator is proposed to use the APA as the component filter in impulsive noise environments, and it is easily obtained with convex combination schemes. From this, the proposed algorithm achieves robustness against impulsive noise regardless of the convergence state. In addition, the proposed algorithm exhibits a fast convergence rate of the APA for various noise environments. Simulation results verify that the proposed algorithm adequately combines the advantages of the two component filters for system identification scenarios. [ABSTRACT FROM AUTHOR]

The development of a national audiovisual industry into a domestic and Ibero-American market scope in diverse exhibit screens, for the main ten countries of Unasur, faces new limitations and possibilities in a digitized and global environment. This is an analysis on the results of the five-year period 2010-2014, in terms of film premieres, public assistance, and the relationship among exhibited films by country of origin. The availability of various formats is addressed, and also the policies about Virtual Print Fee and screen quotas, in an unresolved integration of mechanisms for cooperation and joint regulation that effectively impact on the diversity offered and the consumption habits. [ABSTRACT FROM AUTHOR]

Ultrashort-throw projectors allow large screens in very limited space and without concerns about shadows that obstruct the image, which is the development trend of the projector industry. However, the technical problems of image distortion and uneven illumination restrict its industrialization development. The freeform mirror is the core component of the ultrashort-throw projection system, and the high-performance design method and corresponding manufacturing technology are the key factors of ultrashort-throw projectors to achieve rapid development. In this paper, the initial shape of the freeform mirror is designed by geometric construction with energy mapping. The ultrashort-throw projection imaging system model is established. After optimization, the throw ratio is 0.2, the projection screen is 80 inches, the total length of the projection lens is 155 mm, the field of view is 152 deg, and the edge illumination of the system is 97% of the center illumination. The assembly and adjustment method of the lens and the processing and coating method of the mirror are studied, and the experimental prototype is assembled and tested. This paper aims to establish the theory of freeform surface design and provide theoretical and technical support for the construction and system design of off-axis complex freeform surface. [ABSTRACT FROM AUTHOR]

Introduction: This paper attempts to verify the anatomical veracity of the belief that in order to enter into a posterior calyx one must aim for the medial calyx during a percutaneous nephrolithotomy (PCNL). Methods: Volume rendered and maximum intensity projection reconstructions of normal pelvicalyceal systems were assessed in various rotational planes. An experienced urologist decided the appropriate access for PCNL in the upper, interpole and lower calyx on each side. The selected calyx was then viewed on anteroposterior sections to decide whether they were projecting laterally or medially. Results: Of the 508 calyces studied, the posterior calyx was projecting laterally in 72% and medially in 28%. In the upper calyx, the posterior calyx was projecting laterally in a majority of cases, 94% on the right and 89% on the left. In the right lower calyx, the posterior calyx was pointing laterally in 86%, whereas the distribution on the left was 64%. Conclusion: Our results refute the belief that the medial calyx is always synonymous with the lateral calyx. [ABSTRACT FROM AUTHOR]

We report a new LC with low viscosity and high clearing point ( Tc ~102 °C) for color-sequential projection displays. Using a 1.95-µm mixed-mode twisted nematic cell, the averaged gray-to-gray response time is less than 1 ms, which is ~3.6× faster than the current state of the art. Such a mixed-mode twisted nematic liquid-crystal-on-silicon can be used for near-to-eye wearable projection displays and head-up displays in vehicles. [ABSTRACT FROM AUTHOR]

When walking within a CAVE-like system, accommodation distance, parallax, and angular resolution vary according to the distance between the user and the projection walls, which can alter spatial perception. As these systems get bigger, there is a need to assess the main factors influencing spatial perception in order to better design immersive projection systems and virtual reality applications. In this paper, we present two experiments that analyze distance perception when considering the distance toward the projection screens and parallax as main factors. Both experiments were conducted in a large immersive projection system with up to 10-meter interaction space. The first experiment showed that both the screen distance and parallax have a strong asymmetric effect on distance judgments. We observed increased underestimation for positive parallax conditions and slight distance overestimation for negative and zero parallax conditions. The second experiment further analyzed the factors contributing to these effects and confirmed the observed effects of the first experiment with a high-resolution projection setup providing twice the angular resolution and improved accommodative stimuli. In conclusion, our results suggest that space is the most important characteristic for distance perception, optimally requiring about 6- to 7-meter distance around the user, and virtual objects with high demands on accurate spatial perception should be displayed at zero or negative parallax. [ABSTRACT FROM AUTHOR]