31-10-2012, 04:13 PM
COMPUTER GRAPHICS (XCS 354) Two Mark Question
COMPUTER GRAPHICS.pdf (Size: 119.41 KB / Downloads: 83)
1. Define Computer graphics.
Computer graphics remains one of the most existing and rapidly growing
computer fields. Computer graphics may be defined as a pictorial representation or
graphical representation of objects in a computer.
2. What is meant by scan code?
When a key is pressed on the keyboard, the keyboard controller places a code
carry to the key pressed into a part of the memory called as the keyboard buffer. This
code is called as the scan code.
3. What is meant by refreshing of the screen?
Some method is needed for maintaining the picture on the screen. Refreshing of
screen is done by keeping the phosphorus glowing to redraw the picture repeatedly.
(i.e.)By quickly directing the electronic beam back to the same points.
4. Define Random scan/Raster scan displays?
Random scan is a method in which the display is made by the electronic beam
which is directed only to the points or part of the screen where the picture is to be drawn.
The Raster scan system is a scanning technique in which the electrons sweep from
top to bottom and from left to right. The intensity is turned on or off to light and unlight
the pixel.
5. List out the merits and demerits of Penetration techniques?
The merits and demerits of the Penetration techniques are as follows
• It is an inexpensive technique
• It has only four colors
• The quality of the picture is not good when it is compared to other
techniques
• It can display color scans in monitors
• Poor limitation etc.
6. List out the merits and demerits of DVST?
The merits and demerits of direct view storage tubes [DVST] are as follows
• It has a flat screen
• Refreshing of screen is not required
• Selective or part erasing of screen is not possible
• It has poor contrast
• Performance is inferior to the refresh CRT.
7. What do you mean by emissive and non-emissive displays?
The emissive display converts electrical energy into light energy. The plasma
panels, thin film electro-luminescent displays are the examples.
The Non emissive are optical effects to convert the sunlight or light from any
other source to graphic form. Liquid crystal display is an example.
8. List out the merits and demerits of Plasma panel display?
Merits
• Refreshing is not required
• Produce a very steady image free of Flicker
• Less bulky than a CRT.
Demerits
• Poor resolution of up to 60 d.p.i
• It requires complex addressing and wiring
• It is costlier than CRT.