邮电网络与信息高速公路

介绍了深圳市邮电局计算机网络的体系结构与系统功能，并通过分析网络建设过程中所遇到的问题，指出了我国信息高速公路建设中可能出现和应该注意的问题。     

基于运动矢量的视频图象数字水印算法

数字水印技术是近年发展起来的一种用于数字产品版权保护和真伪性论证的新兴技术。与静止图象相比，视频水印技术要满足盲检的要求。本文根据运动矢量的特征值ρl，提出了一种视频图象水印新算法。实验结果表明，所提出的水印算法简单、快速，能满足视频编码的实时性要求；算法与现有的视频压缩标准有很好的兼容性；水印的提取具有盲检功能，无需原图象；水印的嵌入不影响I帧的图象质量，与嵌入水印前的原压缩图象相比，嵌入水印后的视频图象信噪比损失很小。     

ATM网VBR编码会议电视业务模型的研究

文章研究了ATM网中VBR编码的会议电视业务的模型，提出一阶自回归、瑞利分布残差而不是高斯分布的AR序列模型──RAR（1），实验表明，该模型能产生足够多的大信元帧数，这对于研究信元丢失率特性具有至关重要的影响，而且简单实用。此外，RAR（1）模型在较少（16个）和较多（128个）VBR信源统计复用时，能很好地拟合实际的会议电视业务的统计数据。     

中央电视台第一个数字化演播室视频系统介绍

数字电视系统在提高图像质量方面已显示出极大的优越性。因此，世界各国电视台都已开始数字化的进程，中国也不例外。本文详细介绍了中央电视台第一个数字化演播室－８００ｍ＾２演播室的视频系统，包括视频系统数字信号格式的确定，主要设备的特点以及演播室数字视频系统的主要特点等，供广大同行参考。     

Neural architecture for robotic vision sensor that discounts uneven illumination in a manufacturing environment

Computer vision algorithms for inspection or pick-and-place operations often depend on spatially uniform illumination of a workplace. This necessitates expensive lighting fixtures. To discount effects of uneven illumination we designed and tested a neural network that can adaptively control light sensitivity at the photosensor level. Our neural network architecture consists of multiple layers with hexagonally arranged nodes. All nodes have partially overlapping receptive fields of different spatial frequencies. Feedforward connections are excitatory while feedback pathways subserve lateral inhibition. The outputs of these nodes are combined so as to maximize the signal-to-noise ratio while constantly resetting thresholds to maintain high sensitivity. Our connectionist architecture can account for many characteristics attributed to the lightness constancy phenomenon observed in biological systems. The results suggest that our module maintains high sensitivity over the whole domain of intensities without interfering with transmission of visual information embedded in spatial discontinuities of intensity.     

A geometry-based error estimation for cross-ratios

For choosing specific cross-ratios as 2D projective coordinates in various computer vision applications, a reasonable error analysis model is usually required. This investigation adopts the assumption of normal distribution for positioning errors of point features in an image to formulate the error variances of cross-ratios. Based on a geometry-based error analysis, a straightforward way of identifying the cross-ratios with minimum error variances is proposed. Simulation results show that the proposed approach, as well as a further simplified alternative, yield much better estimations of minimum error variances in terms of accuracy, cost, and stability compared with some other methods, e.g., the one based on the rule given by Georis et al. (IEEE Trans. Pattern Anal. Mach. Intell. 20 (4) (1998) 366). Some causes of the performance differences in the estimations are explained using a special configuration of point features.     

基于非接触精密视觉测量的硬盘磁头头偏测量系统

应用基于机器视觉的非接触测量技术对计算机硬盘磁头的头偏测量，不仅满足了磁头生产防污、防ESD的需要，而且实现了精密测量的需要；对测量数据的采集处理以及SPC实时监控，有效地实现了生产过程的控制和预报；与FIS系统的连接实现了生产数据的可追溯性，为生产管理现代化提供一个强有力的工具。系统已广泛应用于硬盘磁头生产线。     

Foveation-Based Error Resilience and Unequal Error Protection over Mobile Networks

By exploiting new human-machine interface techniques, such as visual eyetrackers, it should be possible to develop more efficient visual multimedia services associated with low bandwidth, dynamic channel adaptation and robust visual data transmission. In this paper, we introduce foveation-based error resilience and unequal error protection techniques over highly error-prone mobile networks. Each frame is spatially divided into foveated and background layers according to perceptual importance. Perceptual importance is determined either through an eye tracker or by manually selecting a region of interest. We attempt to improve reconstructed visual quality by maintaining the high visual source throughput of the foveated layer using foveation-based error resilience and error correction using a combination of turbo codes and ARQ (automatic reQuest). In order to alleviate the degradation of visual quality, a foveation based bitstream partitioning is developed. In an effort to increase the source throughput of the foveated layer, we develop unequal delay-constrained ARQ (automatic reQuest) and rate compatible punctured turbo codes where the punctual pattern of RCPC (rate compatible punctured convolutional) codes in H.223 Annex C is used. In the simulation, the visual quality is significantly increased in the area of interest using foveation-based error resilience and unequal error protection; (as much as 3 dB FPSNR (foveal peak signal to noise ratio) improvement) at 40% packet error rate. Over real-fading statistics measured in the downtown area of Austin, Texas, the visual quality is increased up to 1.5 dB in PSNR and 1.8 dB in FPSNR at a channel SNR of 5 dB.     

基于轮廓线匹配的二维重迭物体的识别

本文提出一种基于轮廓线匹配的二维重迭物体的识别算法,并采用一种点模式匹配的快 速算法进行特征点序列的匹配,通过引进形状移位数的概念和利用问题中的各种约束条件,提 高了物体识别速度.     

新闻直播系统中字幕机备份及应急处理实例

简单介绍新闻直播系统中字幕机的接入方法、备份机制、数据共享以及应急处理方案。