Raster Scan Displays and Systems

These flashcards cover key concepts related to raster scan displays and systems, aiding in understanding for exam preparation.

What is a raster scan display?

A raster scan display is a system where an electron beam sweeps across the screen one row at a time, creating an image based on stored intensity values for each pixel.

What is a refresh buffer?

A refresh buffer, also known as a frame buffer, is a memory area that holds the set of intensity values for all the screen points in a raster scan display.

What happens at the end of each scan line in a raster display?

The electron beam returns to the left side of the screen to begin displaying the next scan line.

How many bits does a black-and-white raster system typically use per pixel?

A simple black-and-white raster system typically uses one bit per pixel.

What is the maximum number of bits per pixel that high-quality raster systems can use?

High-quality raster systems can use up to 24 bits per pixel.

What does interlacing mean in the context of raster scan systems?

Interlacing refers to the process where frames are displayed in two passes, scanning every other line first to reduce flickering and improve the perception of smooth motion.

What is the purpose of a video controller in an interactive raster graphics system?

The video controller manages the operation of the display device and directly accesses the frame-buffer memory for graphics rendering.

What does scan conversion refer to?

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

How is the coordinate system typically defined in a raster graphics system?

The coordinate system is usually defined with origin at the lower left corner, with positive x values increasing to the right and positive y values increasing from bottom to top.

What are some examples of random scan display applications?

Examples include calligraphic displays, stroke writing displays, and pen plotters.