This paper addresses the problem of minimizing energy consumption as well as maximizing the coverage area for 3D video sensor nodes deployed over a 2D target area in a wireless video sensor network. ...Reducing the number of active video sensor nodes helps decrease energy consumption, but decrease the coverage area as well as connectivity in the network. The problem is solved initially by a multi-objective integer linear programming based approach (APP_7) which provides an optimal solution but leads to intractability for a large-sized network due to the non-deterministic polynomial time-hard complexity of the problem. This fact motivates us to design a non-dominated sorting genetic algorithm-II based heuristic (APP_8), which generates a near-optimal solution and that is substantiated by comparing the simulation results of APP_7 with APP_8, and two existing greedy heuristics (EX_1, EX_11) for small-sized problem. Simulation experiments are conducted also to compare the results of APP_8 with EX_1 and EX_11 for large-sized network. Between two heuristics, EX_11/(EX_1) is better in terms of energy consumption/(area coverage). It has been observed that for the large-sized network (i.e. node density 100 on the target area of size 75 × 75 square meters) APP_8 is able to reduce energy consumption by 47.76% from EX_11, whereas area coverage is decreased by 0.51% from EX_1, which confirms the acceptability of APP_8 as the proper heuristic in such a scenario.
Background
In previous reports on experiences with an exoscope, this new technology was not found to be applicable for transsphenoidal pituitary surgery. As a specialized center for pituitary ...surgery, we were using a 4K 3D video microscope (Orbeye, Olympus) to evaluate the system for its use in transsphenoidal pituitary surgery in comparison to conventional microscopy.
Method
We report on 296 cases performed with the Orbeye at a single institution. An observational study was conducted with standardized subjective evaluation by the surgeons after each procedure. An objective measurement was added to compare the exoscopic and microscopic methods, involving surgery time and the initial postoperative remission rate in matched cohorts.
Results
The patients presented with a wide range of pathologies. No serious events or minor complications occurred based on the usage of the 4K 3D exoscope. There was no need for switching back to the microscope in any of the cases. Compared to our microsurgically operated collective, there was no significant difference regarding duration of surgery, complications, or extent of resection. The surgeons rated the Orbeye beneficial in regard to instrument size, positioning, surgeon’s ergonomics, learning curve, image resolution, and high magnification.
Conclusions
The Orbeye exoscope presents with optical and digital zoom options as well as a 4K image resolution and 3D visualization resulting in better depth perception and flexibility in comparison to the microscope. Split screen mode offers the complementary benefit of the endoscope which may increase the possibilities of lateral view but has to be evaluated in comparison to endoscopic transsphenoidal procedures in the next step.
With the improvement of people's quality of life, the demand for three-dimensional (3D) video has gradually grown in recent years. However, there are many challenges to providing high-definition and ...high-fidelity 3D video. One of the most difficult challenges for users to provide 3D video is a large amount of energy lost during 3D video transmission. In this study, the authors present a 3D resource allocation system architecture, which can effectively alleviate the problem of large transmission energy loss. They propose that multiple users in a small cell can share video resources in the downlink from the cloud to the client. In the cloud processing, multiple users can share part of the cloud computing work cycle. In the downlink, multiple users can share part of video resources. They presume that some share output bits can be multicast to overall users, and the other bits can be sent to every user in unicast. They model this and derive the simulation results. The simulation results show that the resource allocation scheme in this study achieves greater energy savings under certain conditions than the traditional case without sharing the resource.
Disparity estimation is a popular topic in computer vision and has drawn increasing attention in recent years. In this article, we propose a new multi-stage network for the purpose of two to ...three-dimensional video conversion that contains two training stages: an initial disparity estimation as the first training stage and depth-image-based rendering (DIBR) as an extra component to form the second training stage. In the first training stage, we propose a revised end-to-end feature pyramid stereo network, in which the original non-pyramid structure is replaced by a bottom-up convolutional neural network pyramid for disparity regression. It utilizes the spatial information by concatenating different scale features to boost the performance on boundary consistency. Mirror connections between feature extraction and disparity regression on the corresponding layers are also added to improve the quality of the results. In the second stage, we propose an improved disocclusion filling technique in the DIBR branch and connect the non-neural-network method to the disparity estimation network. This two-stage training strategy can work effectively to generate the improved disparity estimation for two to three-dimensional video conversion. Extensive experiments are conducted and some selected state-of-the-art algorithms are compared with our proposed approach on the popular KITTI2015 and Scene Flow datasets. The results demonstrate that our estimated disparity map can generate high quality 3D images.
The Emerging MVC Standard for 3D Video Services Chen, Ying; Wang, Ye-Kui; Ugur, Kemal ...
EURASIP journal on advances in signal processing,
01/2009, Letnik:
2009, Številka:
1
Journal Article
Recenzirano
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Multiview video has gained a wide interest recently. The huge amount of data needed to be processed by multiview applications is a heavy burden for both transmission and decoding. The joint video ...team has recently devoted part of its effort to extend the widely deployed H.264/AVC standard to handle multiview video coding (MVC). The MVC extension of H.264/AVC includes a number of new techniques for improved coding efficiency, reduced decoding complexity, and new functionalities for multiview operations. MVC takes advantage of some of the interfaces and transport mechanisms introduced for the scalable video coding (SVC) extension of H.264/AVC, but the system level integration of MVC is conceptually more challenging as the decoder output may contain more than one view and can consist of any combination of the views with any temporal level. The generation of all the output views also requires careful consideration and control of the available decoder resources. In this paper, multiview applications and solutions to support generic multiview as well as 3D services are introduced. The proposed solutions, which have been adopted to the draft MVC specification, cover a wide range of requirements for 3D video related to interface, transport of the MVC bitstreams, and MVC decoder resource management. The features that have been introduced in MVC to support these solutions include marking of reference pictures, supporting for efficient view switching, structuring of the bitstream, signalling of view scalability supplemental enhancement information (SEI) and parallel decoding SEI.
Virtual 3D Tour Assistance in Real Estate Management Leimontaitė, Lina; Naimavičienė, Jurga
Baltic journal of real estate economics and construction management,
01/2023, Letnik:
11, Številka:
1
Journal Article
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Over the past decades, more efficient real estate management opportunities have significantly expanded and improved. Complex methods, innovative techniques, and a constantly evolving spectrum of ...information technology have become readily available for common use. When managing real estate for short-term or medium-term rentals, planning, servicing, and ensuring accommodation quality are inseparable aspects, as is providing suitable housing. This process begins at the very first step when potential tenants request a viewing of the preferred property. The situation of the past few years demonstrated that the real estate business was one of the most affected economic sectors by the COVID-19 pandemic. Potential buyers or tenants could no longer physically visit and experience the space as before. Faced with this new reality, there was a need to find a tool to enhance the real estate management strategy by presenting the property. One such tool became the 360-degree photography and virtual tour. The aim of this study is to assess the practical applicability of 3D video tours and evaluate the advantages and drawbacks in short- and medium-term rental business.
Objectives
The purpose of this study was to determine how students perceived the use of a 3D video microscope (3D VM), in comparison to conventional methods, for providing instruction on fixed ...prosthodontics procedures and issuing feedback on student performance.
Methods
From May until December of 2020, University at Buffalo School of Dental Medicine's second‐year students were introduced to fixed prosthodontics. During May and June, a 3D VM was used to live‐stream psychomotor skill demonstrations via a web‐based software. After each procedure, students were asked to complete a short survey regarding their experience with the training. From August until December 2020, students received feedback via: 1. The conventional method, in which faculty use magnification loupes to assess student's perfromance. 2. A 3D VM. Irrespective of the method used, feedback was given following the same defined rubrics. At the conclusion of the semester, students completed a survey comparing their experiences in receiving instruction and feedback. The data were gathered and analyzed descriptively. The chi‐square test (α = .05) was used to gauge if students’ gender had an impact on their perception of feedback methods.
Results
More than 94% of students participated in the surveys. The majority of students had a positive reaction toward the use of the 3D VM for live web‐based training. In regard to receiving feedback, 63% opined that the 3D VM was more effective than the conventional method. Additionally, 80% of students felt that the 3D VM was effective in maintaining physical distance during skill evaluations.
Conclusion
This study examined the use of a 3D VM for teaching psychomotor skills and providing student feedback and compared it to the conventional method. It was found that the use of the 3D VM was perceived positively by students. Gender had no significant impact on students’ attitudes toward the teaching and feedback methods.
3D video services will soon capture the mass market due to the advancement of immersive video technologies (e.g., availability of "3D-Ready" TV monitors at affordable prices) and supportive ...infrastructure (e.g., high bandwidth communication links). In order to provide demanding customers with a better service over unreliable communication channels, system parameters (e.g., operating conditions of the transmission system) can be updated "on the fly". 3D video quality measured at the receiver side can be used as feedback information to fine tune the system parameters. However, measuring 3D video quality is a challenge due to the complex nature of 3D perceptual attributes such as overall image quality, depth perception, etc. In addition, the use of Full-Reference (FR) quality metrics is not a viable solution due to the need of the original 3D video sequence at the receiver side. This paper therefore proposes a Reduced-Reference (RR) quality metric for colour plus depth 3D video transmission using the extracted edge information of depth maps and extracted information from the corresponding colour image in the areas in the proximity of edges. This work is motivated by the fact that the edges/contours of the depth map can represent different depth levels and identify the main foreground objects of the corresponding colour image and hence can be used in quality evaluations. The performance of the method is evaluated for different compression ratios and network conditions and it shows good results compared to its counterpart FR quality metric, with a lower overhead for side-information.
Performance Analysis of Depth Intra-Coding in 3D-HEVC Sanchez, Gustavo; Silveira, Jarbas; Agostini, Luciano V. ...
IEEE transactions on circuits and systems for video technology,
08/2019, Letnik:
29, Številka:
8
Journal Article
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The depth maps intra-frame prediction of 3D High Efficiency Video Coding (3D-HEVC) inherits all texture encoding techniques provided by HEVC and provides new coding tools for depth map predictions. ...These tools comprise algorithms, such as bipartition modes, intra-picture skip, and DC-only. This paper details these tools and shows how they work together with the original HEVC algorithms in the depth map intra-frame prediction for allowing high-efficiency encoding. Besides, this paper analyzes the encoding time and the encoding mode distribution of the intra-frame prediction tools over different quantization scenarios. We aim to provide support for upcoming works on depth map encoding, including complexity reduction and control, real-time embedded systems implementations, and even the development of improved tools to encode depth maps.
View synthesis with depth-image-based rendering (DIBR) has attracted great interest in that it can provide a virtual image at any arbitrary viewpoint in 3-D video and free-viewpoint TV. An inherent ...problem in the DIBR view synthesis is occurrence of holes in a synthesized image, which is also known as disocclusion problem. The disoccluded regions need to be handled properly in order to generate a synthesized view of good quality. This paper provides a fundamental examination of hole generation mechanism in the DIBR oriented view synthesis process. A necessary and sufficient condition of hole generation is first shown, and the corresponding hole location and length is obtained analytically. Furthermore, in view that the conventional hole filling algorithms may fail to fill up a hole correctly when lacking (adequate) visible background information, we propose utilizing the occluded (invisible) information to identify and locate the relevant background pixels around a hole. We then make use of the visible and invisible background information together to perform hole filling. Experimental results validate our hole generation model demonstrating agreement to our analytical results, while our proposed hole filling approach shows superior performance in terms of visual quality of synthesized views.
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