1 / 28

Graphics System

Graphics System. 2011, Fall. Overview of Graphics System. Graphics Hardware Video Display Devices CRT Basic Type of CRT Random-Scan Displays Raster-Scan-Displays Flat-Panel Displays Others Graphics Software. Video Display Devices. Cathode-Ray Tube(CRT). (cathode ray).

adriel
Download Presentation

Graphics System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Graphics System 2011, Fall

  2. Overview of Graphics System • Graphics Hardware • Video Display Devices • CRT Basic • Type of CRT • Random-Scan Displays • Raster-Scan-Displays • Flat-Panel Displays • Others • Graphics Software

  3. Video Display Devices • Cathode-Ray Tube(CRT) (cathode ray)

  4. CRT Basic (1/2) • Phosphor(형광체) • Emit a small spot of light contacted by the electron beam • refresh CRT • To maintain image, refresh electron beam repeatedly • refresh rate : frequency at which a picture is redrawn • Persistence • how long the phosphor continue to emit light after the election beam is removed. • defined as the time to takes 1/10 of its original intensity • general purpose graphic monitors : from 10 to 60 ms

  5. CRT Basic (2/2) • Resolution • the maximum number of points that can be displayed without overlap on a CRT • simply the total number of points in horizontally and vertically • Aspect Ratio. • ratio of vertical points to horizontal points necessary to produce equal-length line in both direction • ex) 4/3 : length of 4 points on horizontal line = length of 3points on vertical line Overlap position (distinguishable  60%) Spot Intensity (Gaussian distribution)

  6. Type of Display Device • Type of CRT • Random-Scan Displays • Raster-Scan-Displays • Flat-Panel Displays • Emissive displays • Nonemissive displays

  7. Random-Scan Display • Vector Display (calligraphic display) • stored as a set of line-drawing commands in an area of memory (refresh display file, display list, display program) • draw a picture one line at a time

  8. Raster-Scan Displays (1/3) • Point plotting device : pixel or pel (Picture Element) • picture info. for all the screen points is stored in separate Memory called Frame buffer (Refresh Buffer) • one row at a time (scan line) from top to bottom

  9. Raster-Scan Displays (2/3) • Frame buffer • Depth of the buffer area, Number of bit planes • Bitmap: one bit per pixel • Pixmap: multiple bits per pixel • Refresh rate • Above about 24 frame per second • Unit of refresh rates  Hz • Ex) 60 frames per second (60Hz)

  10. Raster-Scan Displays (3/3) • Retrace • Horizontal retrace/Vertical retrace • Interlaced refresh procedure • used with slower refreshing rates • avoid flicker • provide adjacent scan lines

  11. Vector vs Raster Displays • Rendering performance • VD: Sensitive to scene and object complexity • RD: Insensitive to scene and object complexity • Memory and processing requirement • VD: variable (depends on scene and object complexity) • RD: Large but constant • Screen space aliasing • VG: None • RG: Frequent • Rendering of interior • VG: No (boundary only) • RG: Yes (Colored, Shaded and Textured surface)

  12. Raster Displays (Bitmap) • Intensity for each pixel depends on the size of frame buffer • ex) Black & White system one bit per pixel is needed the frame buffer is commonly called Bitmap

  13. Raster Displays (Pixmap) • With multiple bits per pixel, we can display gray-scale or color pictures the frame buffer is commonly called pixmap • Ex) Size of Frame Buffer when N=3, with 512 X 512 • Size of Frame buffer = 3 X 512 X 512 = 3 X 256k = 768k

  14. Color CRT Display • Random-scan monitor • Beam-penetration • Two layers of phosphor(red, green) • Raster-scan monitor • Shadow Maskmethod • System has 3 electron guns (R, G, B) • Each Gun is controlled by Frame buffer

  15. True Color System

  16. Raster Graphics System Architecture

  17. Flat-Panel Displays (1/2) • Flat-Panel Displays • Video devices that have reduced volume, weight, and power requirement compared to a CRT • emissive displays • convert electrical energy into light • Plasma Display Panels (PDP) • Less efficient than CRTs (Not as bright, More power) • Large Pixels(~1mm compared to 0.2mm for CRT) • Field Emission Devices (FED) • Limited in size • Light-Emitting Diode (LED) • LED-backlight LCD television • http://www.rambus.com/kr/technology/applications/display/index.html Plasma Display Panels Field Emission Display

  18. Flat-Panel Displays (2/2) • nonemissive displays • convert other source (heat, electromagnetic force,..) into light • Liquid-Crystal Displays (LCD) • Liquid Crystal • The LCD's transition between crystalline and liquid states • less energy on average than their plasma counterparts • a limited viewing angle relative to CRT and plasma displays

  19. Viewing Systems Wide screen view Large-screen stereoscopic view Multi-panel display Curved viewing screen

  20. 3D Display • 3D Display • 360° Light Field Display • Philips 3DTV • Hologram TV

  21. Input Device • Input Device • Keyboard, Mouse • Button Boxes, Dials

  22. Input Device • Trackballs • A ball device that can be rotated with fingers • Spaceballs • Provide six degrees of freedom • Joysticks • Data grove

  23. Input Device • Digitizer • Device for drawing, painting, or interactively selecting position • Graphics tablet • 3D digitizer Desktop tablet 3D digitizing system Artistic Digitizer System

  24. Input Device • Image Scanners flatbed scanner Hand-held scanner Wide-format scanner

  25. Input Device Plasma panels with touch screens Resistive touch screen overlays Light pen Voice system

  26. Hard-Copy Devices Picture generated on a dot-matrix printer Roll-free pen plotter Desktop pen plotter

  27. Graphics Software (1/2) • Two general classifications • general programming package • provides a library of graphics functions that can be used in a programming language such as C, C++, Java, or Fortran • CG API • Computer-graphics application programming interface • Ex) GL, OpenGL, VRML, Java2D, Java3D, Direct3D • Special purpose package • design for nonprogrammers who want to generate picture, graphs • ex) 3D MAXstudio, Autocad, MAYA, WAVEFRONT, ALIAS, SOFTIMAGE for Workstations

  28. Graphics Software (2/2) • Software standard • GKS (Graphical Kernel System) 1984 • 2-D oriented package • PHIGS (Programmer’s Hierarchical Interactive Graphics Standard) • extension of GKS • Increased Capabilities for modeling, rendering • OpenGL • GL (Graphics Library)  Hardware Independent • OpenGL Architecture Review Board • Script Language • Render Man, Radiance, PovRay

More Related