计算机基础,全英文版的课件_精品.ppt

Vector graphic and Digital Video Vector graphic Difference between vector graphic and bitmap graphic? vector graphic: consist of a set of instructions that recreates a picture. You can use vector graphics software to draw a picture, CIRCLE 40 Y200 150 means: create a circle with 40 pixels radius, color it yellow, and place the center of the circle 200 pixels from the left of the screen and 150 pixels from the top of the screen Digital video Composed of a series of frames. Each frame is a still picture. A video display 30 frames per second. * Waveform audio: a digital representation of sound. To record sound, samples of the sound are collected at periodic intervals and stored as numeric data. Sampling rate : the number of times per second that the sound is measured during the recording process. Expressed in hertz(Hz) 4. Representing Audio * Example of Audio encode 采样点 t1 t2 t3 t4 t5 t6 t7 ... 幅值 0011 0101 0111 1001 1011 1101 1110 ... * Analog signals technique parameter Sampling rate ( Hz ex:11.025kHz/22.05kHz) Sampling precision (bit ex:8 bits/16 bits) Track number (single、double) * 采样频率11KHz 8位量化 采样频率22KHz 16位量化 * Circuits and chips What’s a computer chip? the terms computer chip, microchip, and chip originated as technical jargon for integrated circuit. Section C Digital Data Representation integrated circuit is an super-thin slice of semiconducting material packed with microscopic circuit elements, such as wires, transistors, capacitors, logic gates, and resistors.(p27 f1-30) * Section D. Digital processing Programs and instruction sets: How do digital devices process data? The data is manipulated under the control of a computer program. The human-readable version of a program is called source code. * How does source code get converted? The procedure for translating source code into 0s and 1s can be accomplished by a compiler or an interpreter. A compiler converts all the statements in a program in a single batch, and the resulting coll