Chapter01-02.ppt

The difference between GRAPHICS (图形) and IMAGE (图像) GRAPHICS: a collection of geometric shapes with certain attributes. Overview Introduction (1, 2) Output primitives (3, 4) 2D transformations (5, 6) Curves and Surfaces (7) 3D concepts and transformations (8, 9, 10) Visible Surface Detection (11) Applications of Computer Graphics GUI (Graphical User Interface) Computer Aided Design (CAD) Visualization Simulators Movie special effects Games Computer Graphics Hardware 1. Video Display Devices 2. Raster-Scan Systems 3. Random-Scan Systems 4. Input Devices 5. Hard-Copy Devices Computer Graphics Software 2. Software standard * Computer Graphics IMAGE: 2D or 3D array of pixel intensity values. CRT (Cathode-Ray Tube) Electron Gun Focusing System Horizontal Deflection Plates Vertical Deflection Plates Electron Beam Phosphor- Coated Screen Color CRT Electron Gun R B G Shadow Mask Screen Phosphor-Dot Triangle LCD (Liquid-crystal Display) Passive-matrix LCD Liquid Crystal Vertical Transparent Conductor Horizontal Transparent Conductor Light Polarizer Light Polarizer Light Active-matrix LCD Transistor at each pixel location. TFT (Thin-Film Transistor) Plasma Display Gas (Neon mixture) Vertical Transparent Conductor Horizontal Transparent Conductor Three-Dimensional Viewing Devices Stereoscopic vision: two different views for left and right eye. Red-Green glasses. Polarized glasses. Synchronized shutter glasses. New device without glasses. LCD with optical raster and optional motion tracker. Left eye Right eye Horizontal Retrace Vertical Retrace Scan line Progressive-scan: Scan lines are repainted one by one. Refresh rate: Number of times an entire screen is repainted in a second. Interlace: Repaint even-numbered scan lines, then odd-numbered scan lines. The frame buffer: Memory that holds intensity values for all screen pixels. Resolution: Number of horizontal and vertical pixels on the screen. Color depth: Number of bits in frame buffer that represents intensity value