462 research outputs found
No-reference depth map quality evaluation model based on depth map edge confidence measurement in immersive video applications
When it comes to evaluating perceptual quality of digital media for overall quality of
experience assessment in immersive video applications, typically two main approaches stand out:
Subjective and objective quality evaluation. On one hand, subjective quality evaluation offers the
best representation of perceived video quality assessed by the real viewers. On the other hand, it
consumes a significant amount of time and effort, due to the involvement of real users with lengthy
and laborious assessment procedures. Thus, it is essential that an objective quality evaluation model
is developed. The speed-up advantage offered by an objective quality evaluation model, which can
predict the quality of rendered virtual views based on the depth maps used in the rendering process,
allows for faster quality assessments for immersive video applications. This is particularly
important given the lack of a suitable reference or ground truth for comparing the available depth
maps, especially when live content services are offered in those applications. This paper presents a
no-reference depth map quality evaluation model based on a proposed depth map edge confidence
measurement technique to assist with accurately estimating the quality of rendered (virtual) views
in immersive multi-view video content. The model is applied for depth image-based rendering in
multi-view video format, providing comparable evaluation results to those existing in the literature,
and often exceeding their performance
Electronic Imaging & the Visual Arts. EVA 2012 Florence
The key aim of this Event is to provide a forum for the user, supplier and scientific research communities to meet and exchange experiences, ideas and plans in the wide area of Culture & Technology. Participants receive up to date news on new EC and international arts computing & telecommunications initiatives as well as on Projects in the visual arts field, in archaeology and history. Working Groups and new Projects are promoted. Scientific and technical demonstrations are presented
New visual coding exploration in MPEG: Super-MultiView and free navigation in free viewpoint TV
ISO/IEC MPEG and ITU-T VCEG have recently jointly issued
a new multiview video compression standard, called 3D-HEVC,
which reaches unpreceded compression performances for linear,dense camera arrangements. In view of supporting future highquality,auto-stereoscopic 3D displays and Free Navigation virtual/augmented reality applications with sparse, arbitrarily arranged camera setups, innovative depth estimation and virtual view synthesis techniques with global optimizations over all camera views should be developed. Preliminary studies in response to the MPEG-FTV (Free viewpoint TV) Call for Evidence suggest these
targets are within reach, with at least 6% bitrate gains over 3DHEVC
technology
Mathematical Analysis of a Geothermal System
The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to model an oversized tank going down about 50 feet in depth. Then analyze the model using ground temperature gradient data and the SINDATHERMAL Analyzer program. By investigating different glycol flow rates, glycol supply temperatures, and tank dimensions we are able to investigate various designs and analyze the results for optimization. Our results were such that by using our central tank design we were able to design a Geothermal system superior in terms of performance, construction costs, and operating costs to what is in use in industry today. Our conclusion is that there is no need to drill down 300 feet using traditional Geothermal designs when, by using our design, drilling down 50 feet and using a central tank will result in superior heat flo
Mathematical Analysis of a Geothermal System
The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to model an oversized tank going down about 50 feet in depth. Then analyze the model using ground temperature gradient data and the SINDATHERMAL Analyzer program. By investigating different glycol flow rates, glycol supply temperatures, and tank dimensions we are able to investigate various designs and analyze the results for optimization. Our results were such that by using our central tank design we were able to design a Geothermal system superior in terms of performance, construction costs, and operating costs to what is in use in industry today. Our conclusion is that there is no need to drill down 300 feet using traditional Geothermal designs when, by using our design, drilling down 50 feet and using a central tank will result in superior heat flo
Mathematical Analysis of a Geothermal System
The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to model an oversized tank going down about 50 feet in depth. Then analyze the model using ground temperature gradient data and the SINDATHERMAL Analyzer program. By investigating different glycol flow rates, glycol supply temperatures, and tank dimensions we are able to investigate various designs and analyze the results for optimization. Our results were such that by using our central tank design we were able to design a Geothermal system superior in terms of performance, construction costs, and operating costs to what is in use in industry today. Our conclusion is that there is no need to drill down 300 feet using traditional Geothermal designs when, by using our design, drilling down 50 feet and using a central tank will result in superior heat flo
Fast multi-view video plus depth coding with hierarchical bi-prediction
This research work is partially funded by STEPS-Malta and partially by the EU–ESF 1.25.The Multi-view Video Coding (MVC) standard was developed for efficient encoding of multi-view videos. Part of it requires the calculation of both disparity and motion estimations using a bi-prediction structure. These estimations involve an exhaustive search for the optimal compensation vectors from multiple forward and backward reference frames which, while being very efficient in terms of compression, results in high computational costs. This paper proposes a solution that utilizes the multi-view geometry along with the available depth data, to calculate more accurate predictors for both motion and disparity estimations, and for both directions of the prediction structure. Simulation results demonstrate that this technique is reliable enough to allow a substantial reduction in the search areas in all the reference frames. This in turn results in a significant speed-up gain of 3.2 times with a negligible influence on the coding efficiency, while encoding both the color and the depth MVVs.peer-reviewe
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Camera positioning for 3D panoramic image rendering
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.Virtual camera realisation and the proposition of trapezoidal camera architecture are the two broad contributions of this thesis. Firstly, multiple camera and their arrangement constitute a critical component which affect the integrity of visual content acquisition for multi-view video. Currently, linear, convergence, and divergence arrays are the prominent camera topologies adopted. However, the large number of cameras required and their synchronisation are two of prominent challenges usually encountered. The use of virtual cameras can significantly reduce the number of physical cameras used with respect to any of the known
camera structures, hence adequately reducing some of the other implementation issues. This thesis explores to use image-based rendering with and without geometry in the implementations leading to the realisation of virtual cameras. The virtual camera implementation was carried out from the perspective of depth map (geometry) and use of multiple image samples (no geometry). Prior to the virtual camera realisation, the generation of depth map was investigated using region match measures widely known for solving image point correspondence problem. The constructed depth maps have been compare with the ones generated
using the dynamic programming approach. In both the geometry and no geometry approaches, the virtual cameras lead to the rendering of views from a textured depth map, construction of 3D panoramic image of a scene by stitching multiple image samples and performing superposition on them, and computation
of virtual scene from a stereo pair of panoramic images. The quality of these rendered images were assessed through the use of either objective or subjective analysis in Imatest software. Further more, metric reconstruction of a scene was performed by re-projection of the pixel points from multiple image samples with
a single centre of projection. This was done using sparse bundle adjustment algorithm. The statistical summary obtained after the application of this algorithm provides a gauge for the efficiency of the optimisation step. The optimised data was then visualised in Meshlab software environment, hence providing the reconstructed scene. Secondly, with any of the well-established camera arrangements, all cameras are usually constrained to the same horizontal plane. Therefore, occlusion becomes an extremely challenging problem, and a robust camera set-up is required in order to resolve strongly the hidden part of any scene objects.
To adequately meet the visibility condition for scene objects and given that occlusion of the same scene objects can occur, a multi-plane camera structure is highly desirable. Therefore, this thesis also explore trapezoidal camera structure for image acquisition. The approach here is to assess the feasibility and potential
of several physical cameras of the same model being sparsely arranged on the edge of an efficient trapezoid graph. This is implemented both Matlab and Maya. The quality of the depth maps rendered in Matlab are better in Quality
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