3D Video System Research Articles

An Analysis of the Kinetic Energy in the Basket to Handstand on Parallel Bars: A Case Study of an Elite Gymnast

(1) Background: This study aimed to examine the differences in the kinetic energy of the body’s center of mass between successful and unsuccessful attempts at transitioning from a basket to a handstand on the parallel bars. Special attention was given to the analysis of kinetic energy as a key factor in the efficient execution of this complex element. (2) Methods: The sample consisted of 10 successful and 10 unsuccessful attempts performed by an elite gymnast (a multiple-medalist in World and European Championships). All attempts and kinematic data were recorded and analyzed using high-frequency cameras (300 Hz) and the Ariel Performance 3D video system, respectively. Successful and unsuccessful performances were compared using a paired-sample t-test. (3) Results: Significant differences in kinetic energy were observed in the first part of the anti-gravitational phase of movement between successful and unsuccessful attempts. Successful attempts demonstrated a more favorable position at the beginning of this phase, allowing better utilization of accumulated kinetic energy—a higher position of the feet and hips, and a smaller shoulder joint angle at the moment the shoulder passed through the lower vertical. (4) Conclusions: Successful attempts in gymnastics are characterized by better biomechanical optimization and efficient kinetic energy use, achieved through an earlier entry into the second phase of movement with optimal body positioning, leading to greater peripheral and angular velocities crucial for performance.

OBJECTIVE QUANTIFICATION OF DEPTH-OF-FIELD ADVANTAGE IN 3D SURGICAL VIDEO SYSTEM FOR VITREORETINAL SURGERY: Safety and Efficacy in Macular Diseases.

The objective of this study was to demonstrate, based on objective clinical indicators, the advantages of depth of field provided by the 3D surgical video system compared with the traditional microscope during vitrectomy for treating epiretinal membranes or macular holes. A total of 38 patients were included in this study and randomly assigned to either the 3D surgical video group or the conventional microscope group. Surgical parameters, such as the focal plane adjustment frequency, membrane peeling time, and number of attempts to peel the membrane, were recorded for each patient. In addition, patients were followed up for 3 months postoperatively. No significant differences were observed in age, sex, operated eyes, or follow-up rates between the groups. The 3D group had significantly lower focal plane adjustment frequency in macular hole surgery and epiretinal membrane surgery. No significant differences were observed in peeling maneuvers, time, or total surgical time. Postoperative follow-up data showed no significant differences. In conclusion, the 3D surgical video system exhibits potential advantages in depth of field. The 3D surgical video system is a safe and effective technology in vitrectomy for macular diseases.

Enhancing surgical precision and efficiency: a study and comparison of a three-dimensional surgical video system in proliferative diabetic retinopathy surgery.

This study aimed to investigate the safety and efficacy of three-dimensional (3D) surgical video systems for proliferative diabetic retinopathy (PDR). This retrospective clinical case study included 30 patients (30 eyes) with PDR. Patients were divided into two groups: one underwent surgery using a 3D surgical video system (14 cases, 14 eyes), while the other underwent traditional microscope surgery (16 cases, 16 eyes). Safety and efficacy were assessed through predetermined surgical parameters, including surgical duration, intraoperative membrane removal rate, and occurrences during intraoperative and postoperative phases. Our study revealed noteworthy differences in various aspects between the 3D surgical video system group and the traditional microscope surgery group. Specifically, the mean surgical time was 30.25 ± 14.43 mins in the 3D surgical video system group, while it was 38.56 ± 18.71 mins in the traditional microscope surgery group (p = 0.051). Furthermore, the mean membrane removal time was significantly shorter in the 3D group at 2.53 ± 1.52 mins, as compared to 3.23 ± 1.76 mins in the traditional group (p = 0.042). Importantly, the membrane removal rate also displayed a significant difference, with the 3D group at 0.55 ± 0.07 and the traditional group at 0.41 ± 0.11 (p = 0.018). However, no notable differences were observed between the two groups in terms of intraoperative and postoperative incidences. The safety and efficacy obtained using the 3D surgical video system in PDR surgery were comparable to those obtained in traditional microscopic surgery.

Illustration Art Based on Visual Communication in Digital Context

With the rapid advancement of digital media technology in recent years, a digital context has emerged and developed under its influence. Visual communication relies heavily on illustration art. It is widely used in many fields of modern design because it is an important form of visual communication. We propose a visual communication design method for small and weak target images based on temporal and spatial filtering. We calculate the probability of gray pixels appearing using the histogram equalization method, assign thresholds to pixels, and enhance the gray value of images using the equalization process. We analyze the characteristics of each element of the 3D video system and the appropriate visual communication design form after performing calculations and combining them with the basic theory of visual communication design. Create system test links, test indicators, and test results. It has been demonstrated that the restored image integrity of the system is higher than that of the existing system, and that its performance is better.

Gist of the 4th Portion of the Duodenum: Laparoscopic Resection with Pancreas Preservation

In this video, we present the laparoscopic technique of pancreas-preserving segmental resection for GISTs of the 4th portion of the duodenum. A 54-year-old male presented with a polypoid mass of about 3 cm in diameter with a large base, in the 4th portion of the duodenum, about 4 cm from the ampulla. Multiple endoscopic biopsies were taken, and all were negative for adenocarcinoma. CT scan of the abdomen confirmed that the mass, suggestive of GIST, was limited to the duodenum, a limited part intraluminal and the vast majority in the duodenal wall. A laparoscopic segmental resection with a 3D video system was accomplished. The operation lasted 160 min. Recovery was uneventful.

Micro- and macro-borderless surgery using a newly developed high-resolution (4K) three-dimensional video system.

ObjectiveMicrosurgery using conventional optical microscopes or surgical loupes features a limited field of view and imposes a serious strain on surgeons especially during long surgeries. Here we advocate the micro- and macro-borderless surgery (MMBS) using a novel high-resolution (4K) three-dimensional (3D) video system. This study aimed to confirm the applicability of this concept in several surgical procedures.MethodsWe evaluated the possible use and efficacy of MMBS in the following experiments in porcine subjects. Experiment 1 (non-inferiority test) consisted of dissection and anastomosis of carotid artery, portal vein, proper hepatic artery, and pancreatoduodenectomy with surgical loupe versus MMBS. Experiment 2 (feasibility test) consisted of intra-abdominal and intra-thoracic smaller arteries anastomosed by MMBS as a pre-clinical setting. Experiment 3 (challenge on new surgery) consisted of orthotopic liver transplantation of the graft from a donor after circulatory death maintained by machine perfusion. Circulation of the cardiac sheet with a vascular bed in experiment 2 and liver graft during preservation in experiment 3 was evaluated with indocyanine green fluorescence imaging equipped with this system.ResultsEvery procedure was completed by MMBS. The operator and assistants could share the same field of view in heads-up status. The focal depth was deep enough not to be disturbed by pulsing blood vessels or respiratory movement. The tissue circulation could be evaluated using fluorescence imaging of this system.ConclusionsMMBS using the novel system is applicable to various surgeries and valuable for both fine surgical procedures and high-level surgical education.

Quality Assessment for DIBR-Synthesized Images With Local and Global Distortions

Depth-Image-Based-Rendering (DIBR), as one important technique in 3D video system, can be used to generate virtual views. Unfortunately, the DIBR algorithms will introduce various distortions and induce an annoying viewing experience. And it has been proved that traditional 2D assessment quality metrics are not suitable for the DIBR-synthesized views. In this paper, we propose a novel approach to assess the quality of DIBR-synthesized images. The proposed method mainly considers three kinds of DIBR-related distortions: holes distortion, strip-sharped distortion and global sharpness. Holes and strip distortions as two local features are used to characterize the local quality of DIBR-synthesized image, respectively. For the global sharpness we consider the Just Notice Difference (JND) model of human eyes and use it to extract the JND-based global difference for analyzing the global quality. Finally, we combine the holes distortion evaluation, strip distortion evaluation and global quality to infer the overall perceptual quality. Extensive experiments indicate that our method achieves higher accuracy of quality prediction than most competing metrics.

PERCEPTUAL ANSWERS PRESENTED BY SOCCER ATHLETES DURING PRE AND POST­TRAINING PERIODS: A SYSTEMATIC REVIEW WITH METANALYSIS

Perceptual training plays an important role during the teaching and learning process of athletes. This process should be aimed at the development of perceptions, thus improving motor skills and physical abilities of athletes, seeking new methodologies and techniques to make this process easier. Visual perception has a very important cognitive function during the training periods, because when new technologies are introduced for the development of visual perception, they can provide an interesting learning, as well as contribute to the reduction of reaction time, accuracy of athletes. The objective of the present study was to analyze the perceptual responses in athletes during the pre- and post-training periods. This is a systematic review with meta-analysis of randomized clinical studies that analyze the perceptual trainings in athletes, without language restrictions and with dates of studies with at least 20 years, in the following databases: Pubmed, ScienceDirect, ClinicalTrials, VHL (LILACS and MEDLINE), SCOPUS, EBSCO, SciELO, as well as the gray literature base: OpenGrey.eu, DissOnline, and the Reasearch Gate. Three articles were analyzed and comparisons were established between the pre- and post-training periods. After all triage, three articles were analyzed in full and established comparisons between pre-workout, post-workout and control groups. The main results were: Comparison between the training of the post-experimental and post-control groups, with 95% CI between 0.51 and 2.32%. The overall effect test yielded p = 0.02, revealing that such difference was significant. However, the heterogeneity, I² = 62% p value = 0.07, was high. Comparison between pre-experimental and post-experimental training, with 95% CI between -1.60 and 19.40%. The test for the general effect obtained p <0.01, revealing that this difference was significant. However, the heterogeneity, I² = 93% p value <0.01, was also high. From the results found, it is concluded that the percentage of success in the passes of soccer players was maoir after training with 3D video system.

Sparse Representation based Video Quality Assessment for Synthesized 3D Videos.

The temporal flicker distortion is one of the most annoying noises in synthesized virtual view videos when they are rendered by compressed multi-view video plus depth in Three Dimensional (3D) video system. To assess the synthesized view video quality and further optimize the compression techniques in 3D video system, objective video quality assessment which can accurately measure the flicker distortion is highly needed. In this paper, we propose a full reference sparse representation based video quality assessment method towards synthesized 3D videos. Firstly, a synthesized video, treated as a 3D volume data with spatial (X-Y) and temporal (T) domains, is reformed and decomposed as a number of spatially neighboring temporal layers, i.e., X-T or Y-T planes. Gradient features in temporal layers of the synthesized video and strong edges of depth maps are used as key features in detecting the location of flicker distortions. Secondly, dictionary learning and sparse representation for the temporal layers are then derived and applied to effectively represent the temporal flicker distortion. Thirdly, a rank pooling method is used to pool all the temporal layer scores and obtain the score for the flicker distortion. Finally, the temporal flicker distortion measurement is combined with the conventional spatial distortion measurement to assess the quality of synthesized 3D videos. Experimental results on synthesized video quality database demonstrate our proposed method is significantly superior to other state-of-the-art methods, especially on the view synthesis distortions induced from depth videos.

Depth perceptual quality assessment for symmetrically and asymmetrically distorted stereoscopic 3D videos

Depth perception is one of the most important features provided by stereoscopic 3D videos, which is also the major difference to 2D videos. Its quality, called depth perceptual quality or depth quality, is one of the key factors that directly affects the quality of experience of 3D videos. Since 3D video shall be compressed, transmitted and reconstructed in 3D video system, distortion introduced from compression and processing affects the video quality as well as the depth perceptual quality. However, understandings of how the distortions affect the depth perception and how to evaluate the depth perceptual quality of 3D video remain limited. In this paper, subjective experiments are firstly conducted for investigating the compression and processing distortions’ impacts on the perceived depth quality of 3D videos. The subjective experiments over the datasets show that the loss of video details can cause the degradation of the depth perceptual quality in monocular and binocular perspectives. In addition, the relationships between video quality and depth quality for both symmetric and asymmetric distorted 3D stereoscopic videos are analyzed. Both the subjective video quality and depth quality scores are released and available for public. Secondly, an objective depth quality assessment algorithm is proposed for measuring the depth perceptual quality degradation of symmetrically and asymmetrically distorted stereoscopic 3D videos. The experimental results demonstrate that the proposed metric has better consistency with the subjective scores of human vision system compared with the state-of-the-art schemes.

An Assigned Color Depth Packing Method With Centralized Texture Depth Packing Formats for 3D VR Broadcasting Services

The ability to distribute 3D video and audio in traditional television channels is key to deliver three dimensional (3D) virtual reality (VR) broadcasting services, which allows a limited number of connected players and unlimited number of audiences to enjoy 3D video, audio, and passive interactions. Recently, the centralized texture depth packing (CTDP) formats with color depth packing are proposed for delivering 3D videos. In this paper, we revise the procedure of CTDP computation and introduce an assigned color depth packing method that packs the depth information of VR in RGB color space and depacks it in YCbCr or RGB color space even if the video coder is conducted in YCbCr 4:2:0 and 4:2:2 chroma formats. Under uncoded and coded conditions, the performances of the depacked depth, texture, and synthesized frames of the proposed method are compared to those of the existed packing algorithms. Finally, a trial 3D video and VR broadcasting system based on the left-ad-right CTDP format have been tested in Hsin Yeong, a cable company in Taiwan.

Low-Cost Stereoscopic Recordings of Neurologic Surgery Operative Microscopy for Anatomic Laboratory Training

Stereoscopic video recordings of operative microscopy during neuroanatomic dissections are an important component of surgical training and research in well-financed medical schools and teaching hospitals. However, the high cost of the latest operative microscopes with integrated video recording equipment can be a limiting factor in their worldwide use. The aim of the present work is to provide a simple low-cost 3-dimensional (3D) stereoscopic operative microscope recording system that can be used even in economically and resource-limited locations. This is achieved by using readily available smartphones, smartphone accessories, and computer software. Stereoscopic recording is accomplished by attaching and aligning matched or similar smartphones to the eyepieces of an operative microscope using readily available smartphone mounting connectors. Video recordings from the smartphones are then transferred to a personal computer and processed with a video-editing software to generate stereoscopic movies that are viewed on a smartphone using virtual-reality glasses. The setup time to mount and align the smartphone cameras typically requires 15-30 minutes. Video image quality and 3D depth presentation is more than sufficient for surgical training and research purposes. The implementation cost ranges from $1,315-$7,066, or much less if smartphones and a computer are already available. The 3D video system demonstrated herein can be implemented on any type of operative microscope, including older units for which commercial stereo recording systems are not available. The system and method presented herein can be readily and affordably implemented in low-budget environments for clinical training and research.

The interaction between suction feeding performance and prey escape response determines feeding success in larval fish.

The survival of larval marine fishes during early development depends on their ability to feed before depleting their yolk reserves. Most larval fish capture prey by expanding their mouth, generating a 'suction flow' that draws the prey into it. These larvae dwell in a hydrodynamic environment that impedes their ability to capture even non-evasive prey; however, the marine environment is characterized by an abundance of evasive prey, predominantly copepods. Copepods sense the hydrodynamic disturbance created by approaching predators and perform high-acceleration escape maneuvers. Using a 3D high-speed video system, we characterized the interaction between Sparus aurata larvae and prey from a natural zooplankton assemblage that contained evasive prey, and assessed the factors that determine the outcome of these interactions. At 8-33 days post hatching, larvae preferentially attacked large prey that was moving prior to the initialization of the strike; however, feeding success was lower for larger, more evasive prey. Thus, larvae were challenged in capturing their preferred prey. Larval feeding success increased with increasing Reynolds numbers, but decreased sharply when the prey performed an escape maneuver. The kinematics of successful strikes resulted in a shorter response time but higher hydrodynamic signature available for the prey, suggesting that strike success in our experiments was determined by brevity rather than stealth: executing a fast strike eliminated a potential escape response by the prey. Our observations of prey selectivity reveal that larval performance, rather than preferences, determines their diet during early development.

View synthesis method for 3D video coding based on temporal and inter view correlation

Recently, in three-dimensional (3D) television, the temporal correlation between consecutive frames of the intermediate view is used together with the inter-view correlation to improve the quality of the synthesised view. However, most temporal methods are based on the motion vector fields (MVFs) calculated by the optical flow or block-based motion estimation which has very high computational complexity. To alleviate this issue, the authors propose a temporal-disparity-based view synthesis (TDVS) method, which uses the MVFs extracted from the bitstreams of side views and motion warping technique to create the temporal correlation between views in the intermediate position. Then a motion compensation technique is used to create a temporal-based view. Finally, the temporal-based view is fused with a disparity-based view which is generated by a traditional depth image-based rendering technique to create the final synthesised view. The fusion of these views is performed based on the side information which is determined and encoded at the sender-side of the 3D video system using a dynamic programming algorithm and rate-distortion optimisation scheme. Experimental results show that the proposed method can achieve the synthesised view with appreciable improvements in comparison with the view synthesis reference software 1D fast (VSRS-1D Fast) for several test sequences.

WLDISR: Weighted Local Sparse Representation-Based Depth Image Super-Resolution for 3D Video System.

In this paper, we propose a Weighted Local sparse representation based Depth Image Super-Resolution (WLDISR) schemes aiming at improving the Virtual View Image (VVI) quality of 3D video system. Different from color images, depth images are mainly used to provide geometrical information in synthesizing VVI. Due to the view synthesis characteristics difference between textural structures and smooth regions of depth images, we divide the depth images into edge and smooth patches and learn two local dictionaries, respectively. Meanwhile, the weight term is derived and incorporated explicitly in the cost function to denote different importance of edge structures and smooth regions to the VVI quality. Then, local sparse representation and weighted sparse representation are jointly used in both dictionary learning and reconstruction phases in depth image super-resolution. Based on different optimizations on learning and reconstruction modules, three WLDISR schemes, WLDISR-D, WLDISR-R, and WLDISR-ALL, are proposed. Experimental results on 3D sequences demonstrate that the proposed WLDISR-D, WLDISR-R, and WLDISR-ALL schemes can achieve more than 1.9-, 2.03-, and 2.16-dB gains on average, respectively, in terms of the VVIs' quality, as compared with the state-of-the-art schemes. In addition, the visual quality of VVIs is also improved.

Convolutional Neural Network Based Synthesized View Quality Enhancement for 3D Video Coding.

The quality of synthesized view plays an important role in the three dimensional (3D) video system. In this paper, to further improve the coding efficiency, a convolutional neural network (CNN) based synthesized view quality enhancement method for 3D High Efficiency Video Coding (HEVC) is proposed. Firstly, the distortion elimination in synthesized view is formulated as an image restoration task with the aim to reconstruct the latent distortion free synthesized image. Secondly, the learned CNN models are incorporated into 3D HEVC codec to improve the view synthesis performance for both view synthesis optimization (VSO) and the final synthesized view, where the geometric and compression distortions are considered according to the specific characteristics of synthesized view. Thirdly, a new Lagrange multiplier in the rate-distortion (RD) cost function is derived to adapt the CNN based VSO process to embrace a better 3D video coding performance. Extensive experimental results show that the proposed scheme can efficiently eliminate the artifacts in the synthesized image, and reduce 25.9% and 11.7% bit rate in terms of peak-signal-to-noise ratio (PSNR) and structural similarity (SSIM) index, which significantly outperforms the state-of-theart methods.

Application of a three-dimensional video system in the training for uniportal thoracoscopic surgery.

Three-dimensional (3D) video systems offer better depth perception and are associated with improved performance during endoscopic or robotic surgery. We compared the impact of a 3D video system with a two-dimensional (2D) video system on a simulation program for uniportal thoracoscopic surgery. We launched an endoscopic simulation program for uniportal surgery using a 3D high-definition video system for training surgeons and medical students. This program included three basic surgical skills: (I) peg transfer, (II) passing a needle through a 3-mm hole, and (III) suturing on a tailor-made skin model. We evaluated the impact of 3D vision during simulation for uniportal surgery in each task. Overall, 113 trainees (85 surgeons in training and 28 medical students) who had not experienced a 3D video system were registered in the program. The three surgical simulation skills were evaluated under 2D and 3D video systems. The 3D video system allowed for shorter procedural times [92 participants (80.0%) in task 1, 102 (86.4%) in task 2, and 88 (74.6%) in task 3] and improved performance. Moreover, 65 s in task 1, 145 s in task 2, and 32 s in task 3 were shortened using the 3D video system. Post-simulation survey revealed improved depth perception (n=71, 60.2%) and handling of instruments on the uniportal surgical module (n=39, 33.1%) as advantages of the 3D video system during simulation. Sixty (50.8%) trainees were not negatively affected by the use of the 3D glasses; however, 53 (44.9%) felt eye discomfort during simulation. We concluded that the 3D video system has potential advantages, such as improved procedure time and handling of instruments, during basic simulation of uniportal surgery for surgical trainees.

Experimental study of mechanical properties of steel 40Cr in the necking area of specimen during the postcritical deformation

The work is devoted to the experimental study of the evolution of mechanical properties of the structural steel 40Cr during postcritical deformation of solid cylindrical specimens in conditions of strain localization formation in the form of neck at tension. The methodical issues of providing tests by ‘specimen from specimen’ scheme are observed. Different levels of preliminary postcritical deformation of initial samples are realized, and the results of testing specimens cut from the initial samples with a neck are obtained. To measure the displacement and strain fields in the gauge length of specimens with the neck the noncontact 3D video system Vic 3D, based on the digital images correlation technique, was used. On the base of test results, the stiffness and strength of steel 40Cr were evaluated in a necked specimen at various stages of postcritical deformation. The hardness distribution on the specimen after necking was analyzed too. It is shown that the material in the peripheral areas of the gauge length of the sample is in a strengthened state, which does not depend on the degree of previously achieved postcritical deformation, and the strength of the material in the neck-forming zone on the initial specimens is thereby increased.

Regularities of mechanical behavior of steel 40Cr during the postcritical deformation of specimens in condition of necking effect at tension

The work is devoted to the experimental study of mechanical behavior regularities of the structural steel 40Cr under postcritical deformation of specimens in conditions of strain localization formation in the form of neck during extension. The results of testing specimens cut from the initial samples with a neck are given. Various levels of preliminary postcritical deformation of initial samples are implemented. Using a noncontact 3D video system for recording displacement and strain fields of Vic 3D Correlated Solutions, based on the digital images correlation technique, the displacement and strain fields in the gauge length of both the original specimens with the neck and after the groove were recorded in two different schemes to eliminate geometrical heterogeneity. On the base of obtained results, the stiffness and strength of 40Cr steel were evaluated in a necked specimen at various stages of postcritical deformation. It is shown that the material in the peripheral areas of the gauge length of the sample is in a strengthened state, which does not depend on the degree of previously achieved postcritical deformation, and the strength of the material in the neck-forming zone on the initial specimens is thereby increased.

High-resolution depth map generator for 3D video applications using time-of-flight cameras

3D video applications are easily accessible to consumers in this era. In general, high quality depth maps are crucial for interpolating virtual view images that are vital in 3D video applications. Many applications adopt time-of-flight (ToF) cameras due to their real-time distance capturing. Yet, the raw ToF image exhibit limitations such as inaccurate distance values in object boundaries and areas that can absorb the infrared ray. This paper presents a method that handles this issue. The existing methods do not focus on this problem. The proposed method is tested on a camera system that consists of a color camera and a ToF camera. Assuming immersive applications such as teleconferencing or virtual broadcasting, the object of interest is captured. The errors existing in the ToF images are modified as a preprocessing step. Afterward, the low-resolution ToF image is warped to the viewpoint of the color camera; empty areas are filled considering the neighbor information. The depth map results show improvements over the state-of-the-art method. The proposed method can increase the overall quality of the 3D video system, ultimately making 3D video consumer applications more marketable.