Visual rendering of shapes on 2D display devices guided by hand gestures

Designing of touchless user interface is gaining popularity in various contexts. Users can interact with electronic devices using such interfaces even when their hands are dirty or non-conductive. Also, users with partial physical disability can interact with electronic devices with the help of touchless interfaces. In this paper, we propose a Leap Motion controller-based methodology to facilitate rendering of 2D and 3D shapes on display devices. The proposed method tracks finger movements while users perform natural gestures within the field of view of the motion sensor. Then, trajectories are analyzed to extract extended Npen++ features in 3D. These features capture finger movements during the gestures and they are fed to unidirectional left-to-right Hidden Markov Model (HMM) for training. A one-to-one mapping between gestures and shapes, is proposed. Finally, the shapes corresponding to these gestures are rendered over the display using a typical MuPad supported interface. We have created a dataset of 5400 samples recorded by 10 volunteers. Our dataset contains 18 geometric and 18 non-geometric shapes such as “circle”, “rectangle”, “flower”, “cone”, “sphere”, etc. The proposed method has achieved 92.87% accuracy using a 5-fold cross validation scheme. Experiments reveal that the extended 3D features perform better than the existing 3D features when applied for shape representation and classification. The method can be used for developing diverse HCI applications suitable for smart display devices.     

Seed-based authentication for mobile clients across multiple devices

Authenticating users for mobile cloud apps has been a major security issue in recent years. Traditional passwords ensure the security of mobile applications, but it also requires extra effort from users to memorize complex passwords. Seed-based authentication can simplify the process of authentication for mobile users. In the seed-based authentication, images can be used as credentials for a mobile app. A seed is extracted from an image and used to generate one-time tokens for login. Compared to complex passwords, images are more friendly to mobile users. Previous work had been done in seed-based authentication which focused on providing authentication from a single device. It is common that a mobile user may have two or more mobile devices. Authenticating the same user on different devices is challenging due to several aspects, such as maintaining the same credential for multiple devices and distinguishing different users. In this article, we aimed at developing a solution to address these issues. We proposed multiple-device authentication algorithms to identify users. We adopted a one-time token paradigm to ensure the security of mobile applications. In addition, we tried to minimize the authentication latency for better performance. Our simulation showed that the proposed algorithms can improve the average latency of authentication for 40% at most, compared to single-device solutions.     

Bend Passwords: using gestures to authenticate on flexible devices

Upcoming mobile devices will have flexible displays, allowing us to explore alternate forms of user authentication. On flexible displays, users can interact with the device by deforming the surface of the display through bending. In this paper, we present Bend Passwords, a new type of user authentication that uses bend gestures as its input modality. We ran three user studies to evaluate the usability and security of Bend Passwords and compared it to PINs on a mobile phone. Our first two studies evaluated the creation and memorability of user-chosen and system-assigned passwords. The third study looked at the security problem of shoulder-surfing passwords on mobile devices. Our results show that bend passwords are a promising authentication mechanism for flexible display devices. We provide eight design recommendations for implementing Bend Passwords on flexible display devices.     

Tracking,recognition, and distance detection of hand gestures for a 3‐D interactive display

Abstract— This study proposes an interactive system for displays, the technologies of which consists of three main parts: hand‐gesture tracking, recognition, and depth measurement. The proposed interactive system can be applied to a general 3‐D display. In this interactive system, for hand‐gesture tracking, Haar‐like features are employed to detect a specific hand gesture to start tracking, while the mean‐shift algorithm and Kalman filter are adopted for fast tracking. First, for recognizing hand gestures, a principal component analysis (PCA) algorithm is used to localize colored areas of skin, and then hand gestures are identified by comparison with a prepared database. Second, a simple optical system is set up with an infrared laser source and a grid mask in order to project a proposed horizontal stripe pattern. Third, the projected patterns are deciphered to extract the depth information using the Hough‐transform algorithm. The system containing hand‐gesture localization, recognition, and associated depth detection (the distance between the display and the hand), was included in a prototype of an interactive display. Demonstration of rotation recognition of a finger‐pointing hand gesture was successful by using the algorithm of radar‐like scanning.     

Three‐dimensional interaction and autostereoscopic display system using gesture recognition

We propose a 3D interaction and autostereoscopic display system that use gesture recognition, which can manipulate virtual objects in the scene directly by hand gestures and can display objects in 3D stereoscopy. The system consists of a gesture recognition and manipulation part as well as an autostereoscopic display as an interactive display part. To manipulate the 3D virtual scene, a gesture recognition algorithm is proposed, which use spatial‐temporal sequences of feature vectors to match predefined gestures. To get smooth 3D visualization, we utilize the programmable graphics pipeline in graphic processing unit to accelerate data processing. We develop a prototype system for 3D virtual exhibition. The prototype system reaches frame rates of 60 fps and operates efficiently with a mean recognition accuracy of 90%.     

Using gestures to convey internal mental models and index multimedia content

Gestures can serve as external representations of abstract concepts which may be otherwise difficult to illustrate. Gestures often accompany verbal statement as an embodiment of mental models that augment the communication of ideas, concepts or envisioned shapes of products. A gesture is also an indicator of the subject and context of the issue under discussion. We argue that if gestures can be identified and formalized they can be used as a knowledge indexing and retrieval tool and can prove to be useful access point into unstructured digital video data. We present a methodology and a prototype, called I-Gesture that allows users to (1) define a vocabulary of gestures for a specific domain, (2) build a digital library of the gesture vocabulary, and (3) mark up entire video streams based on the predefined vocabulary for future search and retrieval of digital content from the archive. I-Gesture methodology and prototype are illustrated through scenarios where it can be utilized. The paper concludes with results of evaluation experiments with I-Gesture using a test bed of design-construction projects.

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Current transport and aging in direct-current powder electroluminescent display devices

Abstract— Direct-current powder electroluminescent (DCPEL) display devices were excited by unipolar voltage pulses, and current flow through the phosphor was recorded. Devices with different formed layer thicknesses were obtained by varying the forming voltage. For a fixed electric field in the formed layer, the phosphor current did not show a substantial increase as the thickness of the formed layer increased. A model is proposed in which tunnel injection from the p-Cu₂S/i-ZnS:Mn interface of a reverse-biased p-Cu₂S/i-ZnS:Mn/n-SnO₂ structure is thought to be the controlling current mechanism. Aging studies revealed that further forming is the dominant degradation mechanism in the early stages, while load-line degradation and softening become the dominant degradation modes as the aging process is continued. The conventional DCPEL device structure was modified by introducing a thin chromium layer just prior to the deposition of the aluminum back electrode. Incorporating chromium reduced the initial series resistance of the device. A hybrid device employing a thin film (1 μm) of ZnS:Mn, sandwiched between two thin dielectric layers (5 nm), was fabricated; ZnS:Mn,Cu powder was sprayed onto the thin-film sandwich. The hybrid structure showed good luminance without forming; however, device degradation with time was still present.     

Development and characterization of micromachined hollow cathode plasma display devices

In this paper, we report the development of hollow cathode micro plasma devices made using micromachining techniques. Compared with larger discharge devices, micromachined discharge devices operate at much higher pressures, up to 1 atm. Linear current-voltage relationships are obtained, potentially simplifying the control electronics for such devices. The size of micromachined discharge units is reduced and the distribution of sizes and light intensity in an array is more uniform relative to previous devices.     

CloudLines: compact display of event episodes in multiple time-series

We propose incremental logarithmic time-series technique as a way to deal with time-based representations of large and dynamic event data sets in limited space. Modern data visualization problems in the domains of news analysis, network security and financial applications, require visual analysis of incremental data, which poses specific challenges that are normally not solved by static visualizations. The incremental nature of the data implies that visualizations have to necessarily change their content and still provide comprehensible representations. In particular, in this paper we deal with the need to keep an eye on recent events together with providing a context on the past and to make relevant patterns accessible at any scale. Our technique adapts to the incoming data by taking care of the rate at which data items occur and by using a decay function to let the items fade away according to their relevance. Since access to details is also important, we also provide a novel distortion magnifying lens technique which takes into account the distortions introduced by the logarithmic time scale to augment readability in selected areas of interest. We demonstrate the validity of our techniques by applying them on incremental data coming from online news streams in different time frames.     

Piles across space: Breaking the real-estate barrier on small-display devices

We describe an implementation that has users ‘flick’ notes, images, audio, and video files onto virtual, imaginary piles beyond the display of small-screen devices. Multiple sets of piles can be maintained in persistent workspaces. Two user studies yielded the following: Participants developed mental schemes to remember virtual pile locations, and they successfully reinstated pile locations after several days, while situated in varying environments. Alignment of visual cues on screen with surrounding physical cues in situ accelerated a sorting task when compared to other, non-aligned visual cues. The latter, however, yielded better long-term retention.     

Face and gesture recognition: overview

Computerised recognition of faces and facial expressions would be useful for human-computer interface, and provision for facial animation is to be included in the ISO standard MPEG-4 by 1999. This could also be used for face image compression. The technology could be used for personal identification, and would be proof against fraud. Degrees of difference between people are discussed, with particular regard to identical twins. A particularly good feature for personal identification is the texture of the iris. A problem is that there is more difference between images of the same face with, e.g., different expression or illumination, than there sometimes is between images of different faces. Face recognition by the brain is discussed     

SSIP: Split a SIP session over multiple devices

Recently, most of Voice over Internet applications are based on the Session Initiation Protocol (SIP). This paper addresses issues of allowing a user to continue to communicate with a remote party while changing terminals over multiple devices. Specifically, we propose an SIP extension header to improve the Call Transfer mechanism and hide the changing of the terminal from the remote party. We also propose a mechanism to solve the problem of the user needing to terminate all devices separately when a session is split over multiple devices. Finally, the proposed mechanisms are implemented using Sip-Communicator, an open source of SIP.     

Image display algorithms for high‐ and low‐dynamic‐range display devices

Abstract— With interest in high‐dynamic‐range imaging mounting, techniques for displaying such images on conventional display devices are gaining in importance. Conversely, high‐dynamic‐range display hardware is creating the need for display algorithms that prepare images for such displays. In this paper, the current state of the art in dynamic‐range reduction and expansion is reviewed, and in particular the theoretical and practical need to structure tone reproduction as a combination of a forward and a reverse pass is passed.     

Swiping paper: the second hand, mundane artifacts, gesture and collaboration

It is widely recognised that paper remains a pervasive resource for collaboration and yet there has been uncertain progress in developing technologies that aim to enhance paper documents with computational capabilities. In this article, we discuss the design of a technology that interweaves developments in hardware and materials, electronics and software, and seeks to create new affinities between digital content and paper. The design of the technology drew from findings from naturalistic studies of the uses of paper, particularly when considering how ‘users’ might ‘interact’ with the augmented technology. We briefly review these studies and discuss the results of an evaluation of the emerging technology. Analysis of the fine details of the conduct of participants in these assessments suggest how, even when we design simple forms of interaction with a device, these can be shaped and transformed by the participation and collaboration of others.     

Users joining multiple sites: Friendship and popularity variations across sites

Our social media experience is no longer limited to a single site. We use different social media sites for different purposes and our information on each site is often partial. By collecting complementary information for the same individual across sites, one can better profile users. These profiles can help improve online services such as advertising or recommendation across sites. To combine complementary information across sites, it is critical to understand how information for the same individual varies across sites. In this study, we aim to understand how two fundamental properties of users vary across social media sites. First, we study how user friendship behavior varies across sites. Our findings show how friend distributions for individuals change as they join new sites. Next, we analyze how user popularity changes across sites as individuals join different sites. We evaluate our findings and demonstrate how our findings can be employed to predict how popular users are likely to be on new sites they join.     

Motivation,engagement, and performance across multiple virtual reality sessions and levels of immersion

This study investigated changes in learners' motivation, engagement, performance, and spatial reasoning over time and across different levels of virtual reality (VR) immersion. Undergraduate participants explored a virtual solar system via a moderately immersive or highly immersive VR platform over three sessions. In a third condition, participants initially learned with moderate immersion and transitioned to higher immersion after the second session. Following research on novelty effects, we explored whether subjective experiences and performance would decline over time (e.g., decreasing motivation or performance) as participants became familiar with the virtual environment and tools. However, we hypothesized that transitional immersion (i.e., switching from moderate to higher immersion) might lead to a renewed sense of novelty. Results suggested that both moderate and higher levels of immersion were motivating, engaging, and supportive of learning. In contrast to predictions based on novelty effects, these outcomes did not decline overall as learners gained familiarity with the systems. However, transitional immersion emerged as a promising and testable pedagogical approach for future VR education. All participants also showed gains in spatial reasoning.     

Studies in automated hand gesture analysis: an overview of functional types and gesture phases

This paper presents an overview of studies on automated hand gesture analysis, which is mainly concerned with recognition and segmentation issues related to functional types and gesture phases. The issues selected for discussion have been arranged in a way that takes account of problems within the Theory of Gestures that each study seeks to address. Their principal computational factors that were involved in conducting the analysis of automated hand gesture have been examined, and an analysis of open research issues has been carried out for each application dealt with in the studies.