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
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:
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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?
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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. What is persistence?
The time it takes the emitted light from the screen to decay one tenth of its original intensity is
called as persistence.
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9. What is resolution?
The maximum number of points that can be displayed without an overlap on a CRT is called as
resolution.
10. 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.
11. What is Aspect ratio?
The ratio of vertical points to the horizontal points necessary to produce length of lines in both
directions of the screen is called the Aspect ratio. Usually the aspect ratio is ¾.
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12. What is meant by Addressability?
The Addressability is the number of individual dots per inch (d.p.i) that can be created. If the
address of the current dot is (x, y) then the next dot will be (x+y), (x+y+1) etc.
13. What is a dot size?
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Dot size may be defined as the diameter of a single dot on the devices output. Dot size is also
called as the Spot size.
14. What is interdot distance?
Interdot distance is the reciprocal of addressability. If the addressability is large, the interdot
distance will be less. The interdot distance should be less to get smooth shapes.
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15. What is the difference between impact and non-impact printers?
Impact printer press formed character faces against an inked ribbon on to the paper. A line
printer and dot-matrix printer are examples.
Non-impact printer and plotters use Laser techniques, inkjet sprays, Xerographic process,
electrostatic methods and electro thermal methods to get images onto the papers.
Examples are: Inkjet/Laser printers.
16. What are the features of Inkjet printers?
They can print 2 to 4 pages/minutes.
Resolution is about 360d.p.i. Therefore better print quality is achieved.
The operating cost is very low. The only part that requires replacement is ink cartridge.
4 colors cyan, yellow, magenta, black are available.
17. Define pixel.
Pixel is shortened forms of picture element. Each screen point is referred to as pixel or pel.
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18. What is frame buffer?
Picture definition is stored in a memory area called frame buffer or refresh buffer.
19. What are the advantages of laser printer?
High speed, precision and economy.
Cheap to maintain.
Quality printers.
Lasts for longer time.
Toner power is very cheap.
20. What are the advantages of electrostatic plotters?
They are faster than pen plotters and very high quality printers.
Recent electrostatic plotters include a scan-conversion capability.
Color electrostatic plotters are available. They make multiple passes over the paper to
plot color pictures.
to be continue...........
