Self-assembly of cells into functional bioarchitectures with microscale spatial topographies are prevalent in nature. despite the advances to recapitulate the native-like microenvironment in vitro,fabrication of soft ...
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Self-assembly of cells into functional bioarchitectures with microscale spatial topographies are prevalent in nature. despite the advances to recapitulate the native-like microenvironment in vitro,fabrication of soft living materials with a deterministic control on the composition, functionality, and geometry, is still challenging. Here, a versatile, paramagnetically tunable, levitational biofabrication technique within a ring-magnet system, RM-LEV, is developed to assemble single cells or heterogeneous multicellular living architectures in a scaffold-free manner. The self-assembly and contactless biofabrication of multiple cell types into 3d multicellular "levitospheres" is demonstrated, where cellular positions are guided by levitation anddensity, simultaneously. Inherent density anddiamagnetism of different cell types are leveraged to manipulate the geometry and self-assembly of levitospheres into larger complex 3d structures, termed as "levitoids". This approach is further applied to manipulate, position, and culture levitoids within a 3d hydrogel matrix under levitation, which preserves their viability and functionality. Thus, this study provides a foundation to create spatially heterogeneous 3d cellular assemblies with density-coded bio-architectures-which is not previously realized using magnetic levitation. This density-basedcoding approach can be beneficial to study the cross-talk between different cell types within spheroids and organoids, and be broadly applied to 3d bioprinting, tissue engineering, cancer, and neuroscience research.
Three dimensional (3d) i.e., multi-view extension of High Efficiency Video coding (HEVC) standard provides a better compression compared to the simulcast coding (i.e., HEVC) technique by exploiting inter- and intra-vi...
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Three dimensional (3d) i.e., multi-view extension of High Efficiency Video coding (HEVC) standard provides a better compression compared to the simulcast coding (i.e., HEVC) technique by exploiting inter- and intra-view redundancy for multi-view video coding. However, this technique imposes a random access frame delay (RAFd) problem as well as requires huge computational time. In this paper three novel techniques are proposed to overcome the problems mentioned above. Firstly, a simulcast video coding technique is proposed where each view is encoded individually using hierarchical bi-predictive structure with extra virtual reference frame generated by dynamic background modeling (popularly known as McFIS - the most common frame in a scene) of the corresponding view. Secondly a novel technique is proposed using 3d motion estimation (3dME) where a 3d frame is formed using the same temporal frames of all views and motion estimation is carried out for the current 3d frame using dual 3d reference frames. Finally, a modification of 3dME dual reference frame technique (3dME-McFIS) is proposed where 3d McFIS is used as the second reference frame. Experimental results confirm that the proposed three techniques reduce the overall computational time and reduce the RAFd problem with comparable or better rate-distortion performance compared to the HEVC-3d extension. Specifically the proposed3dME-McFIS technique outperforms the HEVC-3d coding standard by improving 0.90 dB PSNR on average, by reducing computational time by 50%, and by reducing RAFd problem compared to the existing HEVC-3d coding standard. (C) 2015 Elsevier B.V. All rights reserved.
due to the limitation of the bandwidth resource and capture resolution of depth cameras, low resolution depth maps should be up-sampled to high resolution so that they can correspond to their texture images. In this p...
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due to the limitation of the bandwidth resource and capture resolution of depth cameras, low resolution depth maps should be up-sampled to high resolution so that they can correspond to their texture images. In this paper, a novel depth map up-sampling algorithm is proposed by exploiting the fractal internal self-referential feature. Fractal parameters which are extracted from a depth map, describe the internal self-referential feature of the depth map, do not introduce inherent scale and just retain the relational information of the depth map, i.e., fractal transforms provide a resolution-independent description for depth maps and could up-sample depth maps to an arbitrary high resolution. Then, an enhancement method is also proposed to further improve the performance of the up-sampleddepth map. The experimental results demonstrate that better quality of synthesized views is achieved both on objective and subjective performance. Most important of all, arbitrary resolution depth maps can be obtained with the aid of the proposed scheme.
In texture-plus-depth format, depth map compression is an important task. different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges...
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In texture-plus-depth format, depth map compression is an important task. different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges. This feature will be employed to form an efficient depth map coding scheme in this paper. Firstly, the histogram of the depth map will be analyzed to find an appropriate threshold that segments the depth map into the foreground and background regions, allowing the edge between these two kinds of regions to be obtained. Secondly, the two regions will be encoded through rate distortion optimization with a shape adaptive wavelet transform, while the edges are lossless encoded with JBIG2. Finally, a depth-updating algorithm based on the threshold and the depth range is applied to enhance the quality of the decodeddepth maps. Experimental results demonstrate the effective performance on both the depth map quality and the synthesized view quality.
This paper introduces the concept of three dimensional (3d) barcodes. A 3d barcode is composed of an array of 3d cells, called modules, and each can be either filled or empty, corresponding to two possible values of a...
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ISBN:
(纸本)9781628414950
This paper introduces the concept of three dimensional (3d) barcodes. A 3d barcode is composed of an array of 3d cells, called modules, and each can be either filled or empty, corresponding to two possible values of a bit. These barcodes have great theoretical promise thanks to their very large information capacity, which grows as the cube of the linear size of the barcode, and in addition are becoming practically manufacturable thanks to the ubiquitous use of 3d printers. In order to make these 3d barcodes practical for consumers, it is important to keep the decoding simple using commonly available means like smartphones. We therefore limit ourselves to decoding mechanisms based only on three projections of the barcode, which imply specific constraints on the barcode itself. The three projections produce the marginal sums of the 3d cube, which are the counts of filled-in modules along each Cartesian axis. In this paper we present some of the theoretical aspects of the 2d and3d cases, anddescribe the resulting complexity of the 3d case. We then describe a method to reduce these complexities into a practical application. The method features an asymmetric coding scheme, where the decoder is much simpler than the encoder. We close by demonstrating 3d barcodes we created and their usability.
In this contribution some 3d plus depth (3d+2Z) schemes currently discussed at JCT-3V (ITU/MPEG) for the coding and transmission of 3d content are compared to the well-known and simpler 2d plus depth (2d+Z) approach, ...
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ISBN:
(纸本)9781479913695
In this contribution some 3d plus depth (3d+2Z) schemes currently discussed at JCT-3V (ITU/MPEG) for the coding and transmission of 3d content are compared to the well-known and simpler 2d plus depth (2d+Z) approach, i.e. the transmission of only one view and its relateddepth map. The results of this comparison are presented with regard to coding performance and quality of the base and virtual views. In the light of these results, the 2d+Z format turns out to be competitive over a broad range of requirements for the delivery of consumer auto-stereoscopic 3d TV. Such a format is much easier to implement and to compress than competing 3d+2Z solutions. It can better deal with low quality depth maps and it doesn't need to bother with left-right consistencies.
In this paper, we present a graphics streaming system for remote gaming in a local area network. The framework aims at creating a networked game platform for home and hotel environments. A local PC based server execut...
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ISBN:
(纸本)9781424417650
In this paper, we present a graphics streaming system for remote gaming in a local area network. The framework aims at creating a networked game platform for home and hotel environments. A local PC based server executes a computer game and streams the graphical output to local devices in the rooms, such that the users can play everywhere in the network. Since delay is extremely crucial in interactive gaming, efficient encoding and caching of the commands is necessary. In our system we also address the round trip time problem of commands requiring feedback from the graphics board by simulating the graphics state at the server. This results in a system that enables interactive game play over the network.
This paper presents a theoretical model as well as relevant psychophysical studies to understand the impact that errors in the motion and stereo estimates have on shape perception. With the confidence level of the sha...
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ISBN:
(纸本)9781424407217
This paper presents a theoretical model as well as relevant psychophysical studies to understand the impact that errors in the motion and stereo estimates have on shape perception. With the confidence level of the shape estimates recovered using motion or stereo under various scene configurations ascertained, a 3d TV system can adaptively select the resolution level of the 3d information to be presented to the viewers. depth cues not effective and aspect of shape not perceivable under a particular configuration can be omitted with little or no apparent adverse effect on the quality of the 3d percept.
In this paper, we present two techniques for streaming the output of computer games to an enddevice for remote gaming in a local area network. We exploit the streaming methods in the European project Games@Large, whi...
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ISBN:
(纸本)9789898111135
In this paper, we present two techniques for streaming the output of computer games to an enddevice for remote gaming in a local area network. We exploit the streaming methods in the European project Games@Large, which aims at creating a networked game platform for home and hotel environments. A local PC based server executes a computer game and streams the graphical and audio output to local devices in the rooms, such that the users can play everywhere in the network. dependent on the target resolution of the enddevice, different types of streaming are addressed. For small displays, the graphical output is captured and encoded as a video stream. For high resolution devices, the graphics commands of the game are captured, encoded, and streamed to the client. Since games require significant feedback from the user, special care has to be taken to achieve these constraints for very low delays.
The standardization of video coding, such as MPEG, has been based on a combination of the discrete cosine transform (dCT) and interframe motion estimation. Recently, on the other hand, there has been interest in algor...
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The standardization of video coding, such as MPEG, has been based on a combination of the discrete cosine transform (dCT) and interframe motion estimation. Recently, on the other hand, there has been interest in algorithms that also apply the transform along the time axis, so that the video picture is transformed in 3d and encoded. The purpose of this paper is to utilize the correlation along the time axis more effectively. Motion estimation based on the phase correlation is introduced. A new 3d coding algorithm for video pictures is proposed in which several error frames are combined as a CUBE, and the frequency transform is also applied in the time direction. In order to encode the transformed CUBE more effectively, 3d EZW-IP (embedded zero-tree wavelet image codec based on intraband partitioning) coding, which is a 3d extension of EZW-IP coding, is applied. By computer simulation, it is shown that the method is better than MPEG2 (TMS) and the effectiveness of introducing the motion estimation is verified, indicating the usefulness of the proposed method. (c) 2006 Wiley Periodicals, Inc.
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