scholarly journals Transmission of 3D Scenes over Lossy Channels

2010 ◽  
Vol 2010 ◽  
pp. 1-17
Author(s):  
Pietro Zanuttigh ◽  
Andrea Zanella ◽  
Federico Maguolo ◽  
Guido Maria Cortelazzo
Keyword(s):  
Three Dimensional ◽  
Unequal Error Protection ◽  
Depth Image ◽  
Protection Scheme ◽  
Unreliable Networks ◽  
Correction Scheme ◽  
Depth Image Based Rendering ◽  
Scene Description ◽  
The Impact

This paper introduces a novel error correction scheme for the transmission of three-dimensional scenes over unreliable networks. We propose a novel Unequal Error Protection scheme for the transmission of depth and texture information that distributes a prefixed amount of redundancy among the various elements of the scene description in order to maximize the quality of the rendered views. This target is achieved exploiting also a new model for the estimation of the impact on the rendered views of the various geometry and texture packets which takes into account their relevance in the coded bitstream and the viewpoint required by the user. Experimental results show how the proposed scheme effectively enhances the quality of the rendered images in a typical depth-image-based rendering scenario as packets are progressively decoded/recovered by the receiver.

scholarly journals The impact of technical parameters on the perception quality of three-dimensional content

2020 ◽  
Vol 29 (4) ◽  
pp. 13-18
Author(s):  
Fabijan Nushi ◽  
◽  
Vladimir Cviljušac ◽  
Lidija Mandić ◽  
◽  
...  
Keyword(s):  
Three Dimensional ◽  
Technical Parameters ◽  
The Impact

scholarly journals Artifact Handling Based on Depth Image for View Synthesis

2019 ◽  
Vol 9 (9) ◽  
pp. 1834 ◽  
Author(s):  
Xiaodong Chen ◽  
Haitao Liang ◽  
Huaiyuan Xu ◽  
Siyu Ren ◽  
Huaiyu Cai ◽  
...  
Keyword(s):  
Objective Evaluation ◽  
Depth Image ◽  
Reference Image ◽  
Depth Information ◽  
Virtual Image ◽  
Hole Filling ◽  
Virtual View ◽  
Depth Image Based Rendering ◽  
Handling Method

The depth image based rendering (DIBR) is a popular technology for 3D video and free viewpoint video (FVV) synthesis, by which numerous virtual views can be generated from a single reference view and its depth image. However, some artifacts are produced in the DIBR process and reduce the visual quality of virtual view. Due to the diversity of artifacts, effectively handling them becomes a challenging task. In this paper, an artifact handling method based on depth image is proposed. The reference image and its depth image are extended to fill the holes that belong to the out-of-field regions. A depth image preprocessing method is applied to project the ghosts to their correct place. The 3D warping process is optimized by an adaptive one-to-four method to deal with the cracks and pixel overlapping. For disocclusions, we calculate depth and background terms of the filling priority based on depth information. The search for the best matching patch is performed simultaneously in the reference image and the virtual image. Moreover, adaptive patch size is used in all hole-filling processes. Experimental results demonstrate the effectiveness of the proposed method, which has better performance compared with previous methods in subjective and objective evaluation.

scholarly journals Free-viewpoint image synthesis using superpixel segmentation

2017 ◽  
Vol 6 ◽  
Author(s):  
Mehrdad Panahpour Tehrani ◽  
Tomoyuki Tezuka ◽  
Kazuyoshi Suzuki ◽  
Keita Takahashi ◽  
Toshiaki Fujii
Keyword(s):  
Three Dimensional ◽  
Image Synthesis ◽  
Physical Distance ◽  
Depth Image ◽  
Reference Image ◽  
Sampling Density ◽  
Superpixel Segmentation ◽  
Limited Sampling ◽  
Reference Images

A free-viewpoint image can be synthesized using color and depth maps of reference viewpoints, via depth-image-based rendering (DIBR). In this process, three-dimensional (3D) warping is generally used. A 3D warped image consists of disocclusion holes with missing pixels that correspond to occluded regions in the reference images, and non-disocclusion holes due to limited sampling density of the reference images. The non-disocclusion holes are those among scattered pixels of a same region or object. These holes are larger when the reference viewpoints and the free viewpoint images have a larger physical distance. Filling these holes has a crucial impact on the quality of free-viewpoint image. In this paper, we focus on free-viewpoint image synthesis that is precisely capable of filling the non-disocclusion holes caused by limited sampling density, using superpixel segmentation. In this approach, we proposed two criteria for segmenting depth and color data of each reference viewpoint. By these criteria, we can detect which neighboring pixels should be connected or kept isolated in each references image, before being warped. Polygons enclosed by the connected pixels, i.e. superpixel, are inpainted by k-means interpolation. Our superpixel approach has a high accuracy since we use both color and depth data to detect superpixels at the location of the reference viewpoint. Therefore, once a reference image that consists of superpixels is 3D warped to a virtual viewpoint, the non-disocclusion holes are significantly reduced. Experimental results verify the advantage of our approach and demonstrate high quality of synthesized image when the virtual viewpoint is physically far from the reference viewpoints.

scholarly journals Simulation of Multi-Camera Indoor and Outdoor 3D Scanner

2018 ◽  
Vol 2 (3) ◽  
pp. 33-41
Author(s):  
Keyword(s):  
Three Dimensional ◽  
System Structure ◽  
3D Scanner ◽  
Background Removal ◽  
Dimensional Reconstruction ◽  
Characteristic Points ◽  
Graphic Engine ◽  
The Impact ◽  
Indoor And Outdoor

Photogrammetry allows a three-dimensional reconstruction of the object based on its multiple photography’s. The quality of the reconstruction result depends mostly on the gloss, the diversity of the texture, the lighting conditions, the quality of the camera calibration and the shape of the object. The article presents the results of a simulation of a multi-camera reconstruction system, for the needs of designing indoor and outdoor 3D scanner. The 3D reconstruction system works by simultaneously taking photographs of cameras located around the object. The simulation was created to investigate the optimal distribution of cameras and projectors casting a pattern that increases the number of characteristic points on the surface of the object. The impact of background removal in images on the reconstruction result as well as the texture quality of the object depending on the resolution and distance of the cameras from the object were also investigated. The graphic engine used to create the simulation also allows testing of impact of various conditions. The presented results prove that the parameters of the system structure, such as the placement of cameras, projectors, the selection of patterns projected by the projectors are important and their values can be determined at the stage of system simulation. The acquired results are promising and will be further investigated.

scholarly journals An evaluation of adhesive sample holders for advanced crystallographic experiments

2014 ◽  
Vol 70 (9) ◽  
pp. 2390-2400 ◽  
Author(s):  
Marco Mazzorana ◽  
Juan Sanchez-Weatherby ◽  
James Sandy ◽  
Carina M. C. Lobley ◽  
Thomas Sorensen
Keyword(s):  
Three Dimensional ◽  
X Ray Diffraction ◽  
Porous Support ◽  
Step Procedure ◽  
Alternative Approach ◽  
Hydration State ◽  
Different Types ◽  
One Step ◽  
The Impact

The hydration state of macromolecular crystals often affects their overall order and, ultimately, the quality of the X-ray diffraction pattern that they produce. Post-crystallization techniques that alter the solvent content of a crystal may induce rearrangement within the three-dimensional array making up the crystal, possibly resulting in more ordered packing. The hydration state of a crystal can be manipulated by exposing it to a stream of air at controlled relative humidity in which the crystal can equilibrate. This approach provides a way of exploring crystal hydration space to assess the diffraction capabilities of existing crystals. A key requirement of these experiments is to expose the crystal directly to the dehydrating environment by having the minimum amount of residual mother liquor around it. This is usually achieved by placing the crystal on a flat porous support (Kapton mesh) and removing excess liquid by wicking. Here, an alternative approach is considered whereby crystals are harvested using adhesives that capture naked crystals directly from their crystallization drop, reducing the process to a one-step procedure. The impact of using adhesives to ease the harvesting of different types of crystals is presented together with their contribution to background scattering and their usefulness in dehydration experiments. It is concluded that adhesive supports represent a valuable tool for mounting macromolecular crystals to be used in humidity-controlled experiments and to improve signal-to-noise ratios in diffraction experiments, and how they can protect crystals from modifications in the sample environment is discussed.

Deinterlacing of depth-image-based three-dimensional video for a depth-image-based rendering system

2013 ◽  
Vol 22 (3) ◽  
pp. 033031 ◽  
Author(s):  
Ran Liu ◽  
Weimin Tan ◽  
Yingjian Wu ◽  
Yingchun Tan ◽  
Bole Li ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Depth Image ◽  
Image Based Rendering ◽  
Depth Image Based Rendering

scholarly journals Parakeet: a digital twin software pipeline to assess the impact of experimental parameters on tomographic reconstructions for cryo-electron tomography

Open Biology ◽  
2021 ◽  
Vol 11 (10) ◽  
Author(s):  
James M. Parkhurst ◽  
Maud Dumoux ◽  
Mark Basham ◽  
Daniel Clare ◽  
C. Alistair Siebert ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Biological Samples ◽  
Electron Tomography ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
Software Pipeline ◽  
Digital Twin ◽  
Cryo Electron Tomography ◽  
The Impact

In cryo-electron tomography (cryo-ET) of biological samples, the quality of tomographic reconstructions can vary depending on the transmission electron microscope (TEM) instrument and data acquisition parameters. In this paper, we present Parakeet, a ‘digital twin’ software pipeline for the assessment of the impact of various TEM experiment parameters on the quality of three-dimensional tomographic reconstructions. The Parakeet digital twin is a digital model that can be used to optimize the performance and utilization of a physical instrument to enable in silico optimization of sample geometries, data acquisition schemes and instrument parameters. The digital twin performs virtual sample generation, TEM image simulation, and tilt series reconstruction and analysis within a convenient software framework. As well as being able to produce physically realistic simulated cryo-ET datasets to aid the development of tomographic reconstruction and subtomogram averaging programs, Parakeet aims to enable convenient assessment of the effects of different microscope parameters and data acquisition parameters on reconstruction quality. To illustrate the use of the software, we present the example of a quantitative analysis of missing wedge artefacts on simulated planar and cylindrical biological samples and discuss how data collection parameters can be modified for cylindrical samples where a full 180° tilt range might be measured.

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