Raster and Random Scan Displays

These flashcards cover key concepts and definitions related to raster and random scan display systems based on the provided lecture notes.

What is a raster scan display?

A raster scan display is a system where the electron beam is swept across the screen one row at a time, creating illuminated spots based on stored intensity values.

What is a pixel in the context of raster displays?

A pixel, or picture element, is the smallest unit of a raster display that can be controlled for intensity.

What is the frame buffer used for in raster scan displays?

The frame buffer stores intensity values for all screen points to be displayed on the screen.

How many bits per pixel are commonly used in high-quality color raster systems?

Up to 24 bits per pixel are used in high-quality systems.

What is the horizontal retrace in a raster scan display?

The horizontal retrace is the return of the electron beam to the left side of the screen after completing a scan line.

What is the purpose of interlaced refresh in some raster scan systems?

Interlaced refresh allows the display of the entire screen in half the time by refreshing every other scan line first, then the remaining lines.

What does a display processor do in interactive raster graphics systems?

A display processor handles graphics-related tasks, freeing the CPU from graphics processing and managing the frame buffer.

What is scan conversion?

Scan conversion is the process of digitizing a picture definition into pixel intensity values for storage in the frame buffer.

How does a random scan display differ from a raster scan display?

A random scan display draws images one line at a time in any specified order, rather than sweeping across rows like a raster display.

What is stored in the display file of a random scan system?

The display file stores a set of line drawing commands that direct the electron beam to draw specific lines to refresh the screen.