Computer multimedia technology majors focus on cultivating knowledge and skills of multimedia production and application in various fields. The following is my professional introduction about computer multimedia technology. Welcome to refer to it!
Knowledge system
This chapter knowledge structure:
Basic concepts and characteristics of multimedia and multimedia technology; Media classification table; Composition of multimedia computer system; Collection methods and creative finishing tools for graphic images, audio, animation and video media materials.
Learning outline
8. 1 Overview of Multimedia Technology
This section mainly introduces the basic concepts of media and multimedia, the classification form of media, the concept and characteristics of multimedia technology, and the development and application of multimedia technology.
8. 1. 1 Basic knowledge
1. Media and multimedia
Media is an intermediary to realize information exchange between people, and is simply the carrier of information. The media is also called the media. Multimedia means multimedia, which can be understood as the general name of various media such as words, graphics, images, animations, sounds and images that directly affect people's senses, that is, the forms of expression and modes of communication of various information carriers.
2. Media classification
The International Telecommunication Union (ITU) classifies media as follows:
(1) Sensory media: such as human voice, characters, music, natural sounds, graphic images, animations, videos, etc. All belong to sensory media.
(2) Representing media: Representing media as information codes in computers, such as ACSII codes, image codes, sound codes, etc.
(3) Performance media: also known as display media, it is the media used by computers to input and output information, such as keyboards, mice, light pens, monitors, scanners, printers, digitizers, etc.
(4) Storage medium: also called medium. Common storage media include hard disk, floppy disk, magnetic tape and optical disk.
(5) Transmission media: such as telephone line, twisted pair, optical fiber, coaxial cable, microwave, infrared ray, etc.
3. Multimedia technology
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Multimedia technology refers to the digital collection, collection, processing, storage and dissemination of words, graphics, images, animations, audio, video and other media through computers.
Multimedia technology involves digital information processing technology, data compression coding technology, high-performance and large-capacity storage technology, multimedia network communication technology, multimedia system hardware and software core technology, multimedia synchronization technology, hypertext hypermedia technology and so on. Among them, digital information processing technology is the basic technology, and data compression coding technology is the core technology.
4. Common sense of media information
The types of sensory media information processed by multimedia technology are as follows:
Text information, graphic images, animations, audio information, video information, etc.
8. 1.2 characteristics of multimedia technology
Multimedia technology has the main characteristics of diversity, interactivity, real-time and integration.
8. 1.3 Development and Application of Multimedia Technology
Computer multimedia technology has gone through three stages:
The first stage is before 1985, which is the embryonic stage of computer multimedia technology. The second stage, 1985 to the early 1990s, was the original standard for multimedia computers. The third stage, from the 1990s to the present, is the stage of rapid development of computer multimedia technology.
The application of multimedia has been extended to all fields of social life, such as educational application, electronic publishing, advertising and information consultation, management information system and office automation, home application, virtual reality and so on.
8.2 Multimedia Computer System
This section introduces the composition of multimedia computer system. MPC refers to a multimedia computer system based on personal computer (PC), which integrates graphics, images, audio, video and other multimedia information processing technologies, including software technology and hardware technology.
8.2. 1 Composition of multimedia computer system
Hardware system of multimedia computer
The hardware system of the computer is at the bottom of the whole system, which is the material basis of the system, including all the hardware devices in the multimedia computer and the multimedia hardware environment composed of these devices.
2. Multimedia software platform
Multimedia software platform is the core system of multimedia software, and its main task is to provide a basic environment for multimedia software development. Generally, it is specially designed for multimedia systems, or it is expanded and transformed on the basis of existing operating systems. Windows NT/2000/2003/XP is the most widely used multimedia software platform running on personal computers.
3. Multimedia development system
Multimedia development system includes multimedia data preparation tools and writing tools.
Multimedia preparation tools are composed of various software tools for collecting and creating multimedia information.
Multimedia authoring tools, also known as multimedia authoring tools or multimedia editing tools, provide multimedia developers with software tools to organize and arrange multimedia data and connect them to form a multimedia application system. Common multimedia authoring tools include icon-based multimedia authoring tools, frame-based multimedia authoring tools, page-based multimedia authoring tools and programming language-based multimedia authoring tools.
4. Multimedia application system
Multimedia application system is a multimedia product made by multimedia developers using multimedia development system, which faces the end users of multimedia.
MPC hardware system
MPC hardware system is based on PC hardware equipment and multimedia accessory hardware. There are two main types of multimedia accessory hardware on MPC hardware system: adapter card and peripheral equipment.
1. Multimedia adapter card
Multimedia accessory hardware is basically added to a computer in the form of an adapter card. There are many types and models of these adapter cards, mainly including: video capture card, sound card, decompression card, video playing card, telephone voice card, fax card, graphic image acceleration card, TV card, CD-I analog card, MODEM card and so on.
2. Multimedia peripherals
Multimedia hardware devices connected to the computer in the form of peripheral devices include: optical drive, scanner, printer, digital camera, touch screen, video camera, video recorder, fax machine, microphone, multimedia speaker, etc.
8.3 Arrangement of graphic image materials
This section describes the important basic concepts related to multimedia material arrangement, and introduces the basic methods and tools of graphic and image material arrangement.
8.3. 1 Basic knowledge
There are two methods to record and process graphic images in computer: vector representation of graphics and bitmap representation.
1. bitmap image
Bitmaps can be seen as patterns on a grid, that is? Plaid? Figure.
Pixel is the basic element of bitmap image. In the bitmap, each small? A cube? When full of colors, it can express image information, each of which is very small. A cube? Called pixels.
In computer system, the number of binary digits used to represent the color of image pixels is called color depth.
The aspect ratio of a bitmap is measured by the number of pixels in the width and height, for example, 800? 600、 1024? 768 etc.
In order to know the actual size of bitmap, the resolution of bitmap image is usually recorded. Resolution refers to the number of pixels in a given unit length, usually measured in inches.
Bitmap images have the characteristics of strong realism, pixel editing, good printing effect, large bitmap file and limited resolution.
2. Vector graphics
Vector diagram describes objects with mathematical formulas and constructs images.
In vector graphics, some simple objects such as points, lines, curves, circles, polygons, spheres, cubes and vector fonts are called primitives, and then complex graphics are composed of these simple primitives.
The most basic feature of vector graphics is that it can make full use of the resolution of output devices to obtain high-precision printed output; Vector graphics have less information, so the file is smaller and can be printed and displayed on the screen quickly; It is highly editable; Compared with bitmap, vector graphics lack realism; Vector graphics can represent three-dimensional objects and generate different views, but in bitmap images, three-dimensional information has been lost, so it is difficult to generate different views.
3. Color theory
Each part of the visible spectrum has a unique value called color.
(1) emitted light and reflected light
We can see some objects because they shine, while others because they reflect light. Objects that emit light directly emit visible colors, while the colors of objects that reflect light are determined by the colors of reflected light.
(2) additive color mixing method and subtractive color mixing method
Additive color mixing method refers to the method of adding different colors to get colors. Television, monitor, etc. Use additive mixed color system. Additive color mixing method has three basic colors of red, green and blue, namely RGB, which is called tricolor or tricolor. The color obtained by subtractive color mixing is the color after subtraction. This is a color system based on the principle of reflected light. The three primary colors in subtractive method are indigo (cyan), magenta (magenta) and yellow (CMY). When these three primary colors are mixed in equal amounts, they appear black. This color system is mainly used for color printing and color printing.
(3) Color model
In order to process colors by computer, people have established various color models to facilitate computer processing. Color model is the most basic knowledge of graphic design. Each model has its own advantages and disadvantages and scope of application. Common color models include RGB color model, CMYK color model, HSB color model, Lab color model, indexed color model, gray color model and so on.
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