abrasion 擦伤，磨损 counterpart 伙伴，副本，对应物 accompaniment 伴随物，附属物 CT(Computed Tomography)计算机析层 aerial 空气的, 虚幻的，天线 cursor (计算机尺的) 游标，指导(的)，光annotate 给„作注解 标(显示器) appear as 作为„出现 arc 电弧 arithmetic算术，算法 artifact 人工制品 asymmetric不对称的 asynchronous transmission 异步传输 at a rate of 以„的速率 attenuation 衰减 audio recording 唱片
auxiliary storage (also called secondary storage) 辅助存储器 avalanche 雪崩
background frame背景框 bar graph条形图
baud rate 波特率
be called upon to 用来„，(被)要求„ be likely to 可能，大约，像要
blur涂污，污损，把界线弄的模糊不清；污点
bps (bits per second) 每秒钟传输的比特 by contrast 相反，而，对比起来
CD-ROM 只读存储器（Compact Disc Read Only Memory） cluster簇
coating 涂层，层 Coaxial cable同轴电缆
coaxial 同轴的
code book 码本
compact disk (简称CD)激光磁盘 compact 紧密的
comparable to 与„可比 compression coding压缩编码
computer mediated communication(CMC)计算机中介通信
congestion 充满，拥挤，阻塞 consensus (意见)一致，同意
constrain 限制，约束，制约，强迫
conversational interaction交互式会话 convey 运输，传递，转换
cylinder 柱面
disk drive 硬盘驱动
DCT(Discrete Cosine Transform)离散余弦变换
deadline (最后)期后，截止时间 degradation 恶化，降级
demountable 可拆卸的 deploy 采用，利用，推广应用 deviate 偏离，与„不同 dielectric wave-guide介质波导 dielectric 电介质，绝缘
digital image compression数字图像分辨率
dilation膨胀，扩张，扩大
discrete 离散，不连续
diskettes (also called floppy disk)软
盘
distortion 失真，畸变 dominant 主要的，控制的，最有力的 DQDB (distributed queue dual bus) 分布式队列双总线
edge detection边缘检测 edge filter边缘滤波器 elapse (时间)经过，消失 Electrical isolation电绝缘
electromagnetic interference (EMI)电磁干扰
encompass 围绕，包围，设法做到 encyclopedia 百科全书
Enormous potential bandwidth巨大的潜在带宽 entropy 熵
erosion腐蚀，侵蚀
extract 抽取，取出，分离
face-to-face meeting面对面会议
facsimile摹写，传真，精确复制，影印 feedback 反馈，回授
Fiber information-carrying capacity光纤信息承载容量
five communication media: kernel核心，要点，精髓，内核
audio,data,fax,image and video五种通Land-sat 地球资源卫星
信媒体：声音、数据、传真、图形和图像 LED (light-emitting-diode) 发光二极管 fractal 分形 front-end 前置，前级 full-duplex transmission 全双工传输 GIS (ground instrumentation system) 地面测量系统
give rise to 引起，使产生 graphics 图示，图解 gray scale image灰度图像 gray scale level灰度级
group decision making集体决议制定 hard disks 硬盘
half-duplex transmission 半双工传输 hazardous 危险的
high capacity storage system高容量存储系统
high definition television 高清晰度电视
high pass filter高通滤波器 histogram equalization直方图均衡 histogram 直方图
Huffman encoding哈夫曼编码 hypertext 超文本
image contrast图像对比度 Immunity to interference and cross-talk抗干扰和无串话
immunity 抗扰，免除，免疫性
implementation 实施，执行，敷设 improve over 在„基础上改善 in comparison with„ 与„比较 in diameter 直径 in excess of 超过
in parallel on 并联到，合并到 ingredient 成分，组成部分，要素 innovative = innovatory 创新的，富有革新精神的
intelligence 智能，智力，信息 intensity 强度
interactive capabilities交互能力 intermediate 中间的 inventory 清单，报表 juxtapose 并置，并列
linearity 线性度 long-haul link长途链路 lossless compression无损压缩 lossy compression有损压缩 low pass filter低通滤波器
Low transmission loss低传输损耗 magnitude spectrum幅度谱
metallic (像)金属的，，(声音)刺耳的 Millimeter wave毫米波 morph变种，变体
motion video活动图像
MRI(Magnetic Resonance Imaging)核磁共振成像
multi-access 多路存取，多路进入 multimedia communication 多媒体通信 no greater than 不大于
noninvasive 非侵略的，非侵害的 nuance 微小的差别(色彩等)
object recognition目标识别
Optical carrier frequency光载频 optical disk光盘
Optical fiber communication光纤通信 optically 光学地，光地
parameter 参数，参量
pass on 传递，切换 perimeter周长，周界
perspective 透视，角度，远景 pervasive 扩大的，渗透的 phase spectrum相位谱 photoconductor 光敏电阻 pin 钉住，扣住，抓住 pixel像素
playback 播放(录音带，唱片) Potential low cost 潜在的低成本 potential 潜势(的)，潜力(的) precursor 先驱，前任 predominance 优势，显著 preference 选择，喜欢
presentation 赠与，图像，呈现，演示 Protective coatings保护层
psycho-acoustic 心理(精神)听觉的；传音
的
radio frequency interference (RFI)无线电频率干扰
read/write heads读/写磁头
reassign再分配；再委派；再制定 reservation 保留，预定 resultant matrix结果矩阵 root mean square 均方根
rows and columns（图像的）行和列 Ruggedness and flexibility结实而柔韧 ruggedness 结实
Run-length encoding行程编码 search and brose检索和浏览 sector 扇区
shade色彩深浅；渐变； Signal security信号保密
simplex transmission 单工传输 singe media单媒体系统
Small size and weight小尺寸和轻重量 sophisticated 复杂的，高级的，现代化的 stem from„ 起源于；由„发生 stereophonic 立体声的 still-image静止图像
storage capacity 存储容量
substantial 多的，大的，实际上的
superimposing 叠加，重叠 supplant 代替，取代 susceptible (to) 敏感的，易受„的 synchronous transmission 同步传输 synthetic synchronization合成同步 synthetic 合成的，综合性的
System reliability and ease of maintenance系统可靠和维护方便 take„into account 考虑，重视„ teleprocessing 远程(信息)处理，遥控处理
tensile 拉力的，张力的
textual 本文的；正文的
The alleviation of duct congestion in cities城市中导管阻塞的减缓 time-lapsed相继的
transient 瞬时的 track 磁道
tutorial 指导教师(的)，指导(的)
uniform 均匀的
variation 变化，变量
vector quantification 矢量量化 video conferencing会议电视 video-clip 录像剪辑 voice-grade 音频级
warping翘面，扭曲，变形
wave-guide 波导 wavelength division multiplexed 波分复用
whimsical 古怪的，反复无常的 with the aid of 借助于，用，通过
Notes
A CD-ROM can store in excess of 500 megabytes (millions of bytes)of data—as compared
with a computer’s hard disk, whose maximum storage capacity is about 200 megabytes.和计算机硬盘相比，一个只读存储器可以存储超过500MB的数据，它的最大存储容量大约为200ＭＢ。 A compact disc (CD) is a laser-read (also termed “optically read”) data storage device
on which audio, video, or textual material can be stored. Although it has been used
primarily to record stereophonic sound and has supplanted the long-playing PHONOGRAPH record as the principal medium for music storage, it offers a huge potential as the medium for the storage of massive amounts of many types of information.压缩盘（CD）是一种激光阅读的数据存储设备（也称“光读”），它是可以存储音频、视频和文体的媒体尽管CD最初用于记录立体声声音并且已经取代了留声机唱片而成为主要的音乐存储信息的媒体，但它作为能存储大量多种信息的媒体仍具有巨大的潜力。 A video system conveys image data in the form of a component that represents brig
htness,and two other components that represent color.It is important to convey the storage has a perceptually similar effect across the entire tone scale form black to white. 一个视频系统以一个代表亮度的分量和另两个带表色彩的分量的形式传送图像数据。传送亮度是很重要的，因为在传输、处理和存储过程中引入噪声在整个从黑到白的范围内也具有很相似的感觉效应。
All compression systems require two algorithms :one for compressing the data at the
source ,and another for decompressing it at the destination .In literature ,these algorithms are referred to as the encoding an decoding algorithms, respectively. 所有压缩系统均需要两种算法: 一个在信源压缩数据, 一个在信宿对数据进行解压。在文献当中, 这两个算法分别被称做编码算法和解码算法。
Although often simpler to implement, analog modulation with an optical fiber
communication system is less efficient , requiring a far higher signal to noise ratio at the receiver than digital modulation .虽然具有光纤系统的模拟调制易于实现，但其效率较低，且要求在接收端有比数字调制高得多的信噪比。
Although the shape of the retina is roughly a section of a sphere,it is topologic
ally two-dimensional. In a camera,for practical reasons, we employ a flat image plane,instead of a spherical image surface.Image system theory concerns analyzing the continuous distribution of power that incident on the image plane.A photographic camera has,in the image plane,film that is subject to chemical change thin layer of particles having carefully controlled size and shape,in a pattern with no coherent structure.If the particles are sufficiently dense,an image can be reproduced that has sufficient information for human observer to get a strong sense of the original scene. The finer the particles and the more densely they are arranged in the film medium,the higher will be the capability of the film to record spatial detail. 尽管视网膜的形状大致是球体的一部分，但是从解剖角度来讲是二维的。出于实际原因，我们在照相机中使用了平面的像平面，而没有使用球面的像平面。成像系统理论关注像平面上能量连续分布的分析。在光学照相机的像平面处有光照下发生化学变化的胶片。光学胶片有效成分是含在一层由大小和形状精心控制的粒子组成的薄层当中。如果粒子密度足够高的话，就可以重现出包含足以令人获得很
强原始场景感信息的图像。在胶片介质中的粒子越细小、排列密度越高，胶片记录空间细节的能力的就越高。
An additional bit called a parity bit is sometimes included at the end of each charcter,
and they detect if one of the data bits has been changed during transmissiom.
在每个字符的后面有时还包括一个称为奇偶校验位的附加位，它们测试数据位在传输过程中是否被意外改变。
As we shall see,velocity is a vector.正如我们将会看到的那样，速度是一个矢量。 Aspect radio is the radio of image width to height. Conventional television has an
aspect radio of 4:3.High-definition television uses a wider radio of 16:9.Cinema commonly uses 1.85:1 or 2.35:1.宽高比是图像的宽度和高度之比。常规电视的宽高比是
4∶3。高清晰度电视使用16∶9的宽高比。摄像机常用1.85∶1或者2.35∶1的宽高比。
At present, the bandwidth available to fiber systems is not fully utilized but
modulation at several gigahertz over a hundred kilometers and hundreds of megahertz over three hundred kilometers without intervening electronics (repeaters) is possible.目前，传输100 km的几GHz的调制信号和传输300 km的几百MHz的调制信号都
是可能的，因此，光纤系统的可用带宽并没有得到充分利用。
Because of their tremendous storage capacities, entire catalogs or reference materials
can be stored on a single optical disk. Some people predict that disks will someday
replace data now stored on film such as microfiche.由于其巨大的存储容量，整个目录或参考资料都可以存储在一张光盘上。有人预言，有朝一日，硬盘数据将取代目前存储在电影微缩胶片上的数据。
By no means do electrons in a wire flow from the positive to the negative.导线中的电子绝不能从正流向负。
Compression rates may be generated by determining the size of the compressed image
in terms of number of bits per image pixel for the original image.压缩比可以通过原始图像每像素所需压缩的比特数来确定。
CT scans are X-rays taken in many directions in a single plane of an object。CT技
术是使用X射线从不同方向对目标的某个平面进行扫描。
Do you know what the potential difference is?你知道电位差是什么吗？
Each sensor is connected to the computer with a simplex transission line because the
computer only needs to receive data from the temperature sensors and does not need to send data back to the sensors.每一个传感器都通过一根单工传输线连接到计算机上，这是因为计算机只需要接收来自温度传感器的数据，而不需要向传感器发送数据。
Every substance,be it water,iron or air,consist of atoms.所有物质，不论是水、铁还
是空气，都是原子构成的。 Hypertext is a precursor to multimedia that was developed several years before the
technology necessary for multimedia became available. 超文本是多媒体的先驱，在多媒体所需技术可用以前，它已发展多年了。 If some form of contamination is introduced or if the alignment of the read/write heads
is altered by something accidentally jarring the computer, the disk head can collide and damage the disk surface, causing a loss of data.如果引入了某种形式的污染或
因为电脑的意外碰撞对读／写磁头的位置造成一定的改变，磁头就会碰撞甚至损坏磁盘表面造成数据丢失。
In contrast to the floppy disk drive, hard disk drives hold from 80 megabytes to
gigabytes and terabytes of information. When purchasing a hard disk, consider storage capacity and seek time, a measure of a hard disk’s access speed. The smaller the numbers, the faster the disk.与软盘驱动器相比，硬盘驱动器具有从８０兆字节到十亿字节和千兆字节的信息量。当购买一个硬盘时，应考虑它的存储容量和存取时间，而衡量硬盘好坏的一个标准是存取速度。该数字越小，硬盘速度越快。
In image processing, a procedure called principal components has been designed to
identify correlation between image bands and to create a new set of transformed
bands that represent a new color space in which the new image bands are uncorrelated.在图像处理过程中，一个称为主分量的过程被设计用以确认图像频谱之间的相关性，并产生一组新的变换频谱，其中新图像频谱互不相关地表示一个新的彩色空间。
In computing, a display is describe by the count of pixels across the width and h
eight of the image . Conventional television would be denote 644x483, which indicates 483 picture lines .But any display system invoves some scanning overhead , so the total number of lines in the raster of conventional video is necessarily greater than 483. 在计算机领域，画面是由图像宽，高方向上的像素描述的常规电视机表示为664*483，这意味着483条图像线。但是，任何显示系统都包含一些用于扫描的开销。因此，常规视频扫描的总数一定大于483。
Introduced in 1992, the Sony MiniDisc measures only 6.35 cm (2.5 in) in diameter, but
it can be used to record as well as play up to 74 minutes of music.1992年引进的
索尼迷你盘直径只有6.35cm（2.5英寸），但它可以录制以及播放长达74分钟的音乐 It has been found that metals are all good conductor.人们发现的金属都是良导体。 It is apparent that current is (directly) proportional to the applied voltage.显然电流与外加电压成正比。 It is the human element that benefits from more than one medium of communication, and
also from the interactive capabilities of multimedia systems.人类从多于一种媒体
的通信，尤其是从多媒体系统的交互性能中大受裨益。
JPEG, an extremely common image compression scheme, uses the discrete cosine transform
(DCT) to concentrate most of the information about an 17×17 sub - block of an image into a few significant coefficients. JPEG是一种极其常用的图像压缩方法, 该方法使用离散余弦变换将图像中17×17小块的大部分信息集中到少数几个重要系数上。
Lossless compression means that a file is compacted without losing any information, so that the reconstructed file is identical to the original。无损压缩是不损失任何信息地将文件进行压缩, 重建得到的文件和原文件是完全一样的。
Low pass filters blur images, high pass filters emphasize sharp changes in gray scale
level, and edge filters locate edges in an image ．低通滤波器使图像变得模糊, 而高通滤波器突出了图像的灰度锐变, 边缘滤波器则对图像边缘进行定位。
Mcluhan,in Understanding Media, considers media as “extension to man”, as
technologies and products giving our senses access to further forms of information. McLuhan在他的《了解多媒体》一书中，把多媒体看作是人类感官的延伸，其技术和产品为人们提供进一步接触各种形式的知觉。
MPEG stands for Moving Picture Experts Group ,is the name of family of standards used
for coding audio-visual information (e.g., movies, video ,music) in a digital
compressed format .The major advantage of MPEG compared to other video and audio coding formats is that MPEG files are much smaller for the same quality .This is
because MPEG uses very sophisticated compression techniques. MPEG代表运动图像专家组, 它是对数字压缩格式视听信息(如电影、录像、音乐)编码的一组标准的统称。与其他视频、音频的编码格式相比, MPEG的主要优势是相同质量下的文件要小得多。这是因为MPEG使用了非常复杂的压缩技术。
One point where they can agree, however, is on the essential role played by multimedia data.但是有一个看法是能取得一致的，即多媒体的主要角色是由多媒体数据来扮演的。 Several different types of computer peripherals may appear as network terminals, and
so also can computers functioning in several different ways.几种不同的计算机外围设备可能作为网络终端出现，几种不同方式运行的计算机也可能作为网络终端出现。 Storing data on hard disks is similar to storing data on diskettes. In order to read
or write data on the surface of the spinning disk platter, the disk drives are designed with access arms, or actuators.在硬盘上存储数据类似于在软盘上存储数据。为了在旋转的磁盘片表面读取或写入数据，磁盘驱动器被设计成具有存取和传动装置。 “Tape recorder” commands to control the sequence and speed of presentation of
information can be used, not just with audio and video information but also to control a sequence of frames of data, fax, and image.使用控制信息显示顺序和速度的“磁带录音机”功能键，不仅可以控制声音和图像信息，而且可以控制数据、传真和图形信息的次序。
Taking the size and weight advantage into account, these optical fiber cables are
generally in terms of storage, transportation, handling and installation to corresponding copper cables, whilst exhibiting at least comparable strength and durability.考虑到光纤尺寸和重量上的优势，一般来说，光缆在贮存、运输、操作和敷设方面都优于相应的铜缆，而其强度和耐用性至少与铜缆相当。
The access times for typical computers in use at this time are about 100 ms, but this
will become faster as better memories are utilized.目前所用的典型计算机存取时间大约为100毫秒，但当采用较好的存储器时，存取时间将会缩短。 The avalanche photodiode (APD) detector is followed by a front-end amplifier and
equalizer or filter to provide gain as well as linear signal processing and noise
bandwidth reduction.前置放大器与均衡器或滤波器跟在雪崩二极管检测器的后面以获得增益、线性信号处理及噪声带宽的抑制。
The CD improves over conventional records and tape recordings with its more uniform
and accurate frequency response, a complete absence of background noise, a wider
dynamic range (the difference between the softest and loudest recordable musical sounds), and longer wear—since nothing mechanical touches the surface of the disc when it is played.CD以其更均匀，精确的频率响应超过了常规的唱片和磁带，它完全没有背景杂音，动态范围（最低和最高可录乐声之间的差别）更宽，并且由于播放时没有与磁盘片表面的机械接触因而耐用。
The combination of computers and data communication places such new requirements on
the systems, which must handle them, that one can refer to them better as
teleprocessing rather than telecommunications.计算机和数据通信的结合向系统提出必须对这些信息进行处理的新要求，以至人们最好称它们为远程信息处理，而不是远程通信。
The efficiency of the machine depends on how fast it can run..该机器的效率取决于它
能运转的多快。
The human eye has the proper that when an image appears on the retina ,the image is
retained for some number of milliseconds before decaying .If a sequence of images is drawn line by at 50 images/sec ,the eye does notice that it is looking at discrete images .All video systems exploit this principle to produce moving picture. 人眼具有这样的特性: 图像出现在视网膜上会保留几毫秒, 然后消失。如果一个图像序列以50幅图像每秒逐行扫描显示, 人们就不会觉得看到的是一幅离散的图像。所有视频系统都是利用这一原理产生运动画面的。
The JPEG(Joint Photographic Experts Group)is used for compressing continuous-tone
still pictures (e.g., photographs).JPEG was developed by photographic experts
working under the joint auspices of ITU ,ISO ,and IEC. JPEG(联合图像专家组)用于压缩连续色调的静止图像(例如照片)。它是ITU、ISO和IEC共同支持的图像专家开发出来的。 The modem on the transmitting computer converts the digital signals to modulated analog
signal tones and transmits them over the telephone lines.发送端计算机的调制解调器把数字信号调制为模拟信号，并通过电话线发送出去。
The most common erasable optical drives use magneto-optical technology, in which a
magnetic field changes the polarity of a spot on the disk that has been heated by a laser.最常见的可擦写光盘驱动使用磁光技术，在这种技术中磁场改变了磁盘上被激光加热的点的极性。
The phase spectrum carries the best information about the locations of the objects in the image．相位谱携带着图像中目标位置的信息。
The sampled digital values, along with error correction data, tracking codes, and
cueing data, are recorded on a digital tape, which is used to make compression-molded plastic disc 12 cm ( 4.72 in) in diameter, each covered by a thin, reflective metallic layer and protected by a clear plastic coating.采样的数据连同纠错数据、道代码和提示数据被记录在数字带上，数字带常常做成直径为12 cm(4.72英寸)的模压型塑料片，每片都覆盖一层薄薄的反光金属，其外层有一层透明塑料保护层。
The sector method for physically organizing data on disks divides each track on the
disk surface into individual storage areas called sectors. Each sectors can contain a specified number of bytes.磁盘数据组织扇区化是把磁盘上的每个磁道划分为不同的存储区域，这些不同的区域就叫做扇区。每个扇区能够存储指定的字节数。
The three-dimensional world is imaged by the lens of the human eye onto the retin
a ,which is populated with photoreceptor cells that respond to light having wa
velengths in the range of about 400 nm to 700 nm. In an imaging system ,we build a camera having a lens and a photosensitive device ,to mimic how the world is perceived by vision. 通过人眼的成像系统，三维世界成像在视网膜上；视网膜上遍布着光接收细胞，这些细胞对波长在400~700 nm范围内的光作出反应。在成像系统中，我们用镜头和光敏器件组成照相机，从而模拟人视觉观察世界的方式。
These advantages of CMC can be expected to apply with greater force in the case of
multimedia communications, where the computer-mediated element has more impact on
the human senses than in the data/text-based situations.由于计算机中介系统对于人的理性影响比数据、文本为基础的方式要大得多，因此，计算机中介系统的优势必将在多媒体通信中得到极大的发挥。
These disks are used for applications such as an auto parts catalog where the
information is changed only occasionally, such as once a year, and a new updated
optical disk is created.这种光盘用于信息量大，不需要经常更改信息内容的场合。比如，一个汽车零件目录，其中的信息是经过一段时间(如一年)才更改一次，需要更改时再制作一个新的光盘就可以了。
These instruments are just what we need.这些仪器正是我们需要的。
These read/write heads float on a cushion of air and do not actually touch the surface of the disk. 这些读/写头在高压气流上漂浮，移动时并不与盘片表面真正接触。
This wavelength division multiplexed operation, particularly with dense packing of
the optical wavelengths (or, essentially, fine frequency spacing), offers the potential for a fiber information- carrying capacity which is many orders of magnitude in excess of that obtained using copper cables or a wideband radio system.应用波分复用(技术)，尤其是密集波分复用(或者说，实质上的精细频分复用)，使光纤的信息载容量能超过电缆或宽带无线系统好多个数量级。
Until these networks are widely deployed, multimedia communications can be based on circuit capabilities at a range of bandwidths and lower bandwidth packet
capabilities, such as X.25 and frame relay.在这些网络被广泛使用以前，多媒体通信可建立在一定带宽范围的电路功能和较低带宽的分组功能的基础上，如X.25和帧中继。 Using these vectors, clusters of vectors are derived using a derived spectral distance
measure.使用这些矢量，用一个导出的频谱距离可推导出矢量簇。
Video scanning systems have traditionally been denoted by their total number of l
ines including sync and blanking overhead , the frame rate in hertz , and an indication of interlace(2:1) or progressive (1:1) scan . 525/59.9/2:1 scanning is used in North America and Japan, with an analog bandwidth for studio video of about 5.5 MHz. 625/50/2:1 scanning is used in Europe and Asia, with an analog bandwidth for studio video of about 6.5MHz. 1125/60/2:1 scanning is in use for high-definition television(HDTV), with an analog bandwidth of about 30 MHz. 传统上，视频扫描系统是由其总线数（包括同步、消隐）、帧速率（以Hz为单位）和扫描方式（交错扫描的2:1或者逐行扫描的1:1）来表征的。在北美和日本，使用625/50/2:1扫描系统，其视频模拟带宽约为5。5MHz。1125/60、2:1扫描系统用于高清晰度电视中，其模拟带宽约为30MHz.
When an image uses only a small portion of the available gray scale levels, histogram
equalization can be used to spread out the usage of gray scale levels over the entire
available range. 当一幅图像只使用了可用灰度级的一小部分时, 可以使用直方图均衡的方法将灰度级的使用扩展到整个可用的范围。
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