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Fresnelets are wavelet-like base functions specially tailored for digital holography applications. We introduce their use in phase-shifting interferometry (PSI) digital holography for the compression of such holographic data. Two compression methods are investigated. One uses uniform quantization of the Fresnelet coefficients followed by lossless coding, and the other uses set portioning in hierarchical trees (SPIHT) coding. Quantization and lossless coding of the original data is used to compare the performance of the proposed algorithms. The comparison reveals that the Fresnelet transform of phase-shifting holograms in combination with SPIHT or uniform quantization can be used very effectively for the compression of holographic data. The performance of the new compression schemes is demonstrated on real PSI digital holographic data. 相似文献
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Virtual reality systems use digital models to provide interactive viewing. We present a 3D digital video system that attempts to provide the same capabilities for actual performances such as dancing. Recreating the original dynamic scene in 3D, the system allows photorealistic interactive playback from arbitrary viewpoints using video streams of a given scene from multiple perspectives 相似文献
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de With P.H.N. Breeuwer M. van Grinsven P.A.M. 《Selected Areas in Communications, IEEE Journal on》1992,10(1):97-121
The authors focus on image data compression techniques for digital recording. Image coding for storage equipment covers a large variety of systems because the applications differ considerably in nature. Video coding systems suitable for digital TV and HDTV recording and digital electronic still picture storage are considered. In addition, attention is paid to picture coding for interactive systems, such as the compact-disc interactive system. The relation between the recording system boundary conditions and the applied coding techniques is outlined. The main emphasis is on picture coding techniques for digital consumer recording 相似文献
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伴随着信息技术的不断发展,超高清数字电视呈现出了强劲的增长势头.分析其中的原因,就在于超高清数字电视能够提供更好的视听享受,让观众看的更清楚.而实现这一目标的技术,就是视频压缩编码技术.本文首先介绍了超高清数字电视视频压缩编码技术的,然后对其基本核心技术进行了分析,并对今后的发展趋势进行了预测. 相似文献
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Describes a novel method of distributing a large number of digital video channels over a passive optical fibre network, while allowing the use of baseband binary receive equipment. The synchronous TDM is sampled, and receive channels are descrambled using a programmable delay-lock loop 相似文献
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Fast embedded compression for video 总被引:2,自引:0,他引:2
An embedded coding algorithm creates a compressed bit stream that can be truncated to produce reduced resolution versions of the original image. Unfortunately, such algorithms are relatively slow. We introduce two new concepts in an effort to address this problem: adaptive embedding and cache-based zerotree processing. 相似文献
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Rate-distortion optimization for video compression 总被引:3,自引:0,他引:3
The rate-distortion efficiency of video compression schemes is based on a sophisticated interaction between various motion representation possibilities, waveform coding of differences, and waveform coding of various refreshed regions. Hence, a key problem in high-compression video coding is the operational control of the encoder. This problem is compounded by the widely varying content and motion found in typical video sequences, necessitating the selection between different representation possibilities with varying rate-distortion efficiency. This article addresses the problem of video encoder optimization and discusses its consequences on the compression architecture of the overall coding system. Based on the well-known hybrid video coding structure, Lagrangian optimization techniques are presented that try to answer the question: what part of the video signal should be coded using what method and parameter settings? 相似文献
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本文结合小波分解和MPEG-4的图像分割技术的优点,提出面向对象的小波变换编码技术。本方案在甚低码率的信道下,解码端可以根据接收到的部分码流恢复出原始图像的结构信息,对带宽不固定的信道有很好的自适应性。文中还对如何在有噪声的信道下进行错误纠正进行了探讨。 相似文献
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Multi-view video plus depth (MVD) format is considered as the next-generation standard for advanced 3D video systems. MVD consists of multiple color videos with a depth value associated with each texture pixel. Relying on this representation and by using depth-image-based rendering techniques, new viewpoints for multi-view video applications can be generated. However, since MVD is captured from different viewing angles with different cameras, significant illumination and color differences can be observed between views. These color mismatches degrade the performance of view rendering algorithms by introducing visible artifacts leading to a reduced view synthesis quality. To cope with this issue, we propose an effective method for correcting color inconsistencies in MVD. Firstly, to avoid occlusion problems and allow performing correction in the most accurate way, we consider only the overlapping region when calculating the color mapping function. These common regions are determined using a reliable feature matching technique. Also, to maintain the temporal coherence, correction is applied on a temporal sliding window. Experimental results show that the proposed method reduces the color difference between views and improves view rendering process providing high-quality results. 相似文献
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Hafner U. Albert J. Frank S. Unger M. 《Selected Areas in Communications, IEEE Journal on》1998,16(1):108-119
Weighted finite automata (WFA) exploit self-similarities within single pictures and also sequences of pictures to remove spatial and temporal redundancies. Their implementation then combines techniques from hierarchical methods related to quadtrees and from vector quantization to achieve performance results for low bit rates which can be put on a par with state-of-the-art codecs like embedded zero-tree wavelet coding. Due to their simple mathematical structure, WFA provide an ideal platform for efficient hybrid compression methods. Therefore, WFA were chosen as a starting point for a fractal-like video compression integrating a hierarchical motion compensation as well as an option to vary the compression quality between “centers of interest” and “background” in a flexible manner 相似文献
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Scalable video compression requires the creation of an encoded bit stream that may be decoded in part if channel bandwidth drops, decoder resources are limited, or a smaller image than the source is desired. A separable spatiotemporal subband decomposition is combined with vector and lattice quantizers modified so that the individual subbands may be decoded scalably. This results in finer bandwidth control and more flexibility than simply discarding entire subbands 相似文献
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首先介绍了立体视觉的基本原理,然后对立体图像的压缩方法分四类进行了综述。对其中用于立体图像序列的两种主要方法:基于“块”匹配的立体图像压缩方法和基于物体的立体图像压缩方法进行了深入探讨。通过对已有成果进行总结和分类,剖析了两种方法的优、缺点,并提出了一些还需要深入研究的问题,如:残差图像编码、遮挡检测、更精确的场景分割等。 相似文献
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用单波长激光制作二维彩色全息图的新方法 总被引:3,自引:0,他引:3
提出了一种密度编码,分区记录二维物体主全息图的二步法真彩色全息新技术,文中对基本原理、设计思想进行了细致描述,并给出计算公式。 相似文献
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This paper presents an efficient compression algorithm for animated three-dimensional (3D) meshes. First, a segmentation approach is applied to achieve the motion estimation. The main idea is to exploit the temporal coherence of the geometry component by using the heat diffusion properties. The motion of the resulting regions is accurately described by 3D affine transforms. These transforms are computed at the first frame to match the subsequent ones. Second, in order to achieve a good compression performance, an efficient rate control mechanism is proposed to quantize the temporal prediction errors. At this stage, a rate-distortion model is used for quantizing the residual information. Comparative coding tests, for irregular 3D mesh sequences, were conducted to evaluate the coding efficiency of the proposed compression scheme. Simulation results show very promising performances. 相似文献
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