2、 Common media types
1. Text. Text includes symbols, symbol font, symbol size, symbol format and color, and symbol coding in data transmission and operation management. At present, the main 14 international standards and industrial standards in the text include ISO 646, IS. I. 646, T. 101. ASC I and GB2312, etc.
2. Ring shape. A graph is a black-and-white or colored graph from a point, line, surface to a three-dimensional space. It is generally generated by a graph editor or program. It is also often called a computer IN shape. When a computer stores a graph file, it actually stores drawing instructions and related drawing parameters. The advantage of graphics is that it can realize stepless amplification without distortion, and it takes up small storage space. The disadvantage is that the color is not rich, and it is difficult to describe complex graphics. Before Renl, the main international standards and industrial standards for graphic coding include T 101、T. 150, ISO 8632, ISO 7942, etc.
3. Image. Image refers to a picture composed of image seeking dot matrix. It includes scanning still images and synthesizing still images. The scanning open image is captured by a scanner, an A/D conversion device or a digital camera. Synthetic still images are created or generated by computer assistance, that is, through programs, screen capture, etc. Image files store pixel lattice values, and there is no structural information in the file format The main Sichuan standards for image coding are] BIG, JPEG and] PEG 2000
4. Video and animation. Video 'j' motion A uses the human eye's pick and feel clock retention feature to quickly play a series of static positive images (Graphics), which can produce a smooth and dynamic effect in the human vision. With regard to the visual forehead and motion, it mainly has the following basic concepts: · execution: it is an independent window view of the complete a, as a part of the view sequence to be played. . 8 Likely lki is based on the whole screen or only occupies a part of the screen. Immortal rate: the number of frames played in plum seconds· Collar: It is stored in bitmap form and requires a large storage capacity. It can be divided into capture motion view and composite motion view. The former is captured by communication camera, calibration/data conversion device, word effect camera, etc; The latter is computer aided creation, which is generated through programs, screen captures, etc. Motion IINI: M motion graphics. It stores objects and j - 7 space-time relations. Therefore, it has semantic information. When playing, it needs to calculate to generate the corresponding view. It is usually generated through animation production forests or programs. The data of moving images is very large. Usually, they can be transmitted or stored only after being sorted Af shrinks the standard types. At present, it mainly includes "261, H. 263, H. 264, MPEG series standards, etc.
5. Sound. The sound report refers to the words, sweat, noise, etc. in the listening model IIA L'i and Sibbin: proposed by quasi majority di ITU - T. Mainly including G 711、G.723. G. 729, etc.
