SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Video

214

Ultrafast video recording of spatiotemporal light distribution in a scattering medium has a significant impact in biomedicine. Although many simulation tools have been implemented to model light propagation in scattering media, existing experimental instruments still lack sufficient imaging speed to record transient light-scattering events in real time. We report single-shot ultrafast video recording of a light-induced photonic Mach cone propagating in an engineered scattering plate assembly. This dynamic light-scattering event was captured in a single camera exposure by lossless-encoding compressed ultrafast photography at 100 billion frames per second. Our experimental results are in excellent agreement with theoretical predictions by time-resolved Monte Carlo simulation. This technology holds great promise for next-generation biomedical imaging instrumentation.

Concepts: Optics, Simulation, Monte Carlo, Monte Carlo method, Monte Carlo methods in finance, Camera, Video, NTSC

25

A feasibility study on a new technique capable of monitoring localised sweat rate is explored in this paper. Wearable devices commonly used in clinical practice for sweat sampling (i.e. Macroducts®) were positioned on the body of an athlete whose sweat rate was then monitored during cycling sessions. The position at which the sweat fills the Macroduct® was indicated by a contrasting marker and captured via a series of time-stamped photos or a video recording of the device during an exercise period. Given that the time of each captured image/frame is known (either through time stamp on photos or the constant frame rate of the video capture), it was therefore possible to estimate the sweat flow rate through a simple calibration model. The importance of gathering such valuable information is described, together with the results from a number of exercise trials to investigate the viability of this approach.

Concepts: Time, Rates, Device, Internet Explorer, Video, Frame rate, NTSC, Telecine

12

Running biomechanics play an important role in the development of injuries. Performing a running biomechanics analysis on injured runners can help to develop treatment strategies. This article provides a framework for a systematic video-based running biomechanics analysis plan based on the current evidence on running injuries, using 2-dimensional (2D) video and readily available tools. Fourteen measurements are proposed in this analysis plan from lateral and posterior video. Identifying simple 2D surrogates for 3D biomechanic variables of interest allows for widespread translation of best practices, and have the best opportunity to impact the highly prevalent problem of the injured runner.

Concepts: Injury, Thought, Biomechanics, Problem solving, The Current, Play, Video, Videocassette recorder

8

A large percentage (68%) of children under age 3 use screen media, such as television, DVDs and video games, on a daily basis. Research suggests that increased screen time in young children is linked to negative health outcomes, including increased BMI, decreased cognitive and language development and reduced academic success. Reviews on correlates of screen time for young children have included preschool age children and children up to age 7; however, none have focused specifically on correlates among infants and toddlers. As research suggests that screen media use increases with age, examining correlates of early media exposure is essential to reducing exposure later in life. Thus, this paper systemically reviews literature published between January 1999 and January 2013 on correlates of screen time among children between 0 and 36 months of age.

Concepts: Time, Photosynthesis, Infant, Redox, Childhood, Photography, Preschool education, Video

4

Participatory processes are effective for digital video production that promotes health and wellbeing with communities from diverse cultural and linguistic backgrounds, including migrants and refugees. Social media platforms YouTube, Vimeo, Flickr and others demonstrate potential for extending and enhancing this production approach. However, differences within and between communities in terms of their quality of participation online suggest that social media risk becoming exclusive online environments and a barrier to health and wellbeing promotion. This article examines the literature and recent research and practice in Australia to identify opportunities and challenges when using social media with communities from diverse cultural and linguistic backgrounds. It proposes a hybrid approach for digital video production that integrates ‘online’ and ‘offline’ participation and engages with the differences between migrants and refugees to support more inclusive health and wellbeing promotion using digital technology.

Concepts: Culture, Linguistics, Anthropology, Australia, Semiotics, Humanities, Video, Structuralism

3

High-efficiency video compression technology is of primary importance to the storage and transmission of digital medical video in modern medical communication systems. To further improve the compression performance of medical ultrasound video, two innovative technologies based on diagnostic region-of-interest (ROI) extraction using the high efficiency video coding (H.265/HEVC) standard are presented in this paper. First, an effective ROI extraction algorithm based on image textural features is proposed to strengthen the applicability of ROI detection results in the H.265/HEVC quad-tree coding structure. Second, a hierarchical coding method based on transform coefficient adjustment and a quantization parameter (QP) selection process is designed to implement the otherness encoding for ROIs and non-ROIs. Experimental results demonstrate that the proposed optimization strategy significantly improves the coding performance by achieving a BD-BR reduction of 13.52% and a BD-PSNR gain of 1.16 dB on average compared to H.265/HEVC (HM15.0). The proposed medical video coding algorithm is expected to satisfy low bit-rate compression requirements for modern medical communication systems.

Concepts: Improve, Medical imaging, Medical physics, Data compression, Video compression, Video, Digital video, Video coding

1

Surgeons are under enormous pressure to continually improve and learn new surgical skills. Novel uses of surgical video in the preoperative, intraoperative, and postoperative setting are emerging to accelerate the learning curve of surgical skill and minimize harm to patients. In the preoperative setting, social media outlets provide a valuable platform for surgeons to collaborate and plan for difficult operative cases. Live streaming of video has allowed for intraoperative telementoring. Finally, postoperative use of video has provided structure for peer coaching to evaluate and improve surgical skill. Applying these approaches into practice is becoming easier as most of our surgical platforms (e.g., laparoscopic, and endoscopy) now have video recording technology built in and video editing software has become more user friendly. Future applications of video technology are being developed, including possible integration into accreditation and board certification.

Concepts: Surgery, Skill, Learning, Learning curve, Video, Film and video technology, Streaming media

1

While exercise digital video disc (DVD) sales have substantially increased over the past decade, little is known on the effectiveness of personal training versus DVD exercises. The purpose of this study was to compare energy expenditures and heart rates of live and DVD vigorously intense exercise sessions. Twenty active and low-to-moderate fit, college-age females completed two identical exercise sessions. Each exercise session consisted of six exercises one session was completed with a personal trainer and the other with a DVD. A portable metabolic analyzer was used to measure oxygen consumption and record heart rate. Both energy expenditure (P < .001) and heart rate (P = .001) were significantly higher during the live exercise session as compared to the DVD exercise session. Rate of perceived exertion (RPE) was significantly higher for the live exercise session compared to the DVD exercise session (P = .045). Lastly, the majority (89%) of the participants reported that they preferred the live exercise session over the DVD exercise session. The results suggest that low-to-moderately fit college aged females not only prefer exercise sessions with a personal trainer but will also demonstrate higher energy expenditures and heart rates.

Concepts: Muscle, Compact Disc, Video, Digital video recorder, Optical disc, Blu-ray Disc, Holographic Versatile Disc, DVD

0

This paper presents a novel approach to content delivery for video streaming services. It exploits information from connected eye-trackers embedded in the next generation of VR Head Mounted Displays (HMDs). The proposed solution aims to deliver high visual quality, in real time, around the users' fixations points while lowering the quality everywhere else. The goal of the proposed approach is to substantially reduce the overall bandwidth requirements for supporting VR video experiences while delivering high levels of user perceived quality. The prerequisites to achieve these results are: (1) mechanisms that can cope with different degrees of latency in the system and (2) solutions that support fast adaptation of video quality in different parts of a frame, without requiring a large increase in bitrate. A novel codec configuration, capable of supporting near-instantaneous video quality adaptation in specific portions of a video frame, is presented. The proposed method exploits in-built properties of HEVC encoders and while it introduces a moderate amount of error, these errors are indetectable by users. Fast adaptation is the key to enable gaze-aware streaming and its reduction in bandwidth. A testbed implementing gaze-aware streaming, together with a prototype HMD with in-built eye tracker, is presented and was used for testing with real users. The studies quantified the bandwidth savings achievable by the proposed approach and characterize the relationships between Quality of Experience (QoE) and network latency. The results showed that up to 83% less bandwidth is required to deliver high QoE levels to the users, as compared to conventional solutions.

Concepts: Marketing, Star Trek: The Next Generation, Virtual reality, Video, Film and video technology, Head-mounted display, Bit rate, Latency

0

This article introduces an analysis-aware microscopy video compression method designed for microscopy videos that are consumed by analysis algorithms rather than by the human visual system. We define the quality of a microscopy video based on the level of preservation of analysis results. We evaluated our method with a bead tracking analysis program. For the same error level in the analysis result, our method can achieve 1,000× compression on certain test microscopy videos. Compared with a previous technique that yields exactly the exact same results by analysis algorithms, our method gives more flexibility for a user to control the quality. A modification to the new method also provides faster compression speed.

Concepts: Visual perception, Visual system, Data compression, Video, Digital video