Use of Fresnelets for phase-shifting digital hologram compression.

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.     

Virtual view generation for 3D digital video

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     

基于数字视频的微细作业系统立体成像方案

分析了现有模拟分时立体成像系统的原理和存在闪烁问题的原因,由于两路CCD信号分时显示使帧频下降,图像存在一定的闪烁感,提出了一种改进的立体成像方案,该方案基于数字视频处理,采用高速的视频解码芯片和DSP芯片,提高了图像显示帧频达到无闪烁立体成像的目的,而且利用插场算法提高了图像的清晰度,有利于对进一步实现视觉跟踪控制或利用视觉信息进行自动控制。     

Data compression systems for home-use digital video recording

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     

超高清数字电视视频压缩编码技术与发展趋势

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.     

基于数字微镜器件的计算全息3维显示

为了进一步研究计算全息3维显示的方法,以数字微镜器件为空间光调制器,采用层析法,结合菲涅耳衍射积分算法中的角谱法,探讨了全息图的计算与数字微镜器件参量之间的关系,并利用修正立轴参考光编码的方式,得到了菲涅耳计算全息图。通过对计算全息图进行数值模拟及实验验证,均得到了较好的再现像。结果表明,该方法实现了3维物体的再现,为计算全息3维显示提供了一种有效的方法。     

Novel sampling technique for digital video demultiplexing,descrambling and channel selection

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     

Fast embedded compression for video

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.     

Rate-distortion optimization for video compression

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?     

一种甚低码率下的面向对象小波变换编码技术

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。     

数字电视地面广播COFDM传输中的软判决技术

深入研究了数字电视地面广播COFDM解调方案中的解映射软判决技术,提出了适用于该系统的信道状态信息CSI提取方法。在此基础上通过算法仿真分析,进一步提出一种新的克服单频和PAL模拟电视同频干扰的消除法并给出计算公式。本设计基于国家数字高清晰度电视总体组的多载波BDB-T传输方案,方案样机采用FPGA实现其相应的硬件电路,经过在实际无线环境中传输测试,证明了所提方法的易实现性和其良好性能。     

Color calibration of multi-view video plus depth for advanced 3D video

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.     

Weighted finite automata for video compression

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     

Multidimensional quantizers for scalable video compression

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     

立体图像序列的压缩方法

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。     

用单波长激光制作二维彩色全息图的新方法

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。     

Segmentation-based compression scheme for 3D animated models

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.