1 Lecture 2 Main components of graphical systems Graphical devices

2 Graphical system: main components

3 Graphical Models. Vector Graphics Vector: a straight line is drawn between the two end-points Monitors, plotters

4 Graphical Models. Vector Graphics Vector: a straight line is drawn between the two end-points Monitors, plotters

5 Graphical Models. Raster Graphics Raster: the images are represented as matrices of colored points (pixels). Modern monitors, printers

6 Graphical Models. Raster Graphics Raster: the images are represented as matrices of colored points (pixels). Modern monitors, printers

7 Vector Model

8 Raster Model

9 Vector vs. Raster Raster  Insensitive to scene complexity  Large, but constant  Textured, colored interiors  Very limited Vector  Sensitive to scene complexity  Variable. Depends on the scene  No. Boundary only  Based on continuous (Euclidean) geometry Parameters  Rendering Performance  Memory and processing  Filled areas, interior  Transformations

10 Vector vs. Raster Conclusions about Raster Model:  It is supported by the modern displays and laser and ink- jet printers  It provides a better graphical appearance (filled areas)  It is difficult to use raster graphics for precise work (design, medical applications)  Difficulties in performing geometrical transformations  The main geometrical primitives such as lines, circles, polygons, etc. need approximation (scan-conversion)

11 Graphical Model. Mixed Model. Mixed Model: the images contain straight lines and curves which are rasterized eventually, as well as textures and filled areas.

12 Input Devices Mouse and trackball

13 Input Devices Joystick

14 Input Devices Tablet and pen

15 Input Devices Light pen and touch screen

16 Input Devices Space ball and data glove (3D data)

17 Input Devices Scanner, digital camera, camcorder

18 Input Devices 3D scanner

19 Output Devices Plotter

20 Output Devices Plotter

21 Output Devices CRT (cathode Ray Tube)

22 Output Devices CRT

23 Output Devices Raster Scan Refresh at least 24 frames/s

24 Output Devices Color CRT

25 Output Devices Color CRT

26 Output Devices Color CRT

27 Output Devices LCD (Liquid Crystal Display)

28 Output Devices Plasma panels

29 Output Devices Ink-jet and laser printers

30 Output Devices Calligraphic (vector) screens