by Dinesh Thakur Category: Basic of Computer Graphics

Bitmapped Font, Bitmap Font: A character FONT in which each individual letter form is stored as a table of PIXELS (a picture), in contrast to an OUTLINE FONT where each character is stored as a set of lines or strokes (a description of how to draw the character). Bitmapped fonts are fast and easy to RENDER onto a screen or printer - by simply copying the bits for the character - and for this reason were preferred on older computer systems (up to and including MS-DOS PCs) that used CHARACTER-BASED displays.



 
by Dinesh Thakur Category: Basic of Computer Graphics

Bump Mapping: An extension of the technique Of TEXTURE MAPPING to create more realistic 3D images, in which an additional BITMAP (the bump map) applied to a surface contains not colour data but small displacements to be applied to the surface normal at each point. After the image is rendered, these displacements alter the angles of reflected rays in such a way as to convey the illusion of surface relief, even though the surface actually remains completely smooth.

 
by Dinesh Thakur Category: Basic of Computer Graphics

Analogue video: A video signal that is captured transmitted and stored as a continuously varying voltage, rather than as a stream of bits as in digital video. Up until the advent of digital TV in the late 1990S, television worked by transmitted analogue video signals, and older video tape recorders such as VHS, PAL, Betamax and Umatic all store analogue signals.

 
by Dinesh Thakur Category: Graphics Devices

Raster Scan methods have increasingly become the dominant technology since about 1975. These methods use the TV type raster scan. The growth in the use of such methods has been dependent on rapidly decreasing memory prices and on the availability of cheap scan generating hardware from the TV industry.

 
by Dinesh Thakur Category: Graphics Devices

Conceptually the Direct View Storage Tube (DVST) behaves like a CRT with highly persistent phosphor. Pictures drawn on there will be seen for several minutes (40-50 minutes) before fading. It is similar to CRT as far as the electronic gun and phosphor-coated mechanisms are concerned. But instead of the electron beam directly writing the pictures on the phosphor coated CRT screen, the writing is done with the help of a fine-mesh wire grid.

 
by Dinesh Thakur Category: Graphics Devices

This was one the earlier CRTs to produce color displays. Coating phosphors of different compounds can produce different colored pictures. But the basic problem of graphics is not to produce a picture of a predetermined color, but to produce color pictures, with the color characteristics chosen at run time.

 
by Dinesh Thakur Category: Graphics Devices

Factors in determining refresh rates

A refresh rate is dependent upon a monitor's horizontal scanning frequency and the number of horizontal lines displayed.The horizontal scanning frequency is the number of times the electron beam sweeps one line and returns to the beginning of the next in one second. Horizontal scanning frequency is measured in kilohertz (kHz).

 
by Dinesh Thakur Category: Graphics Devices

One of the basic and commonly used display devices is Cathode Ray Tube (CRT). A cathode ray tube is based on the simple concept that an electronic beam, when hits a phosphorescent surface, produces a beam of light (momentarily - though we later describe surfaces that produce light intensities lashing over a period of time).

 
by Dinesh Thakur Category: Graphics Devices

Plasma displays are bright, have a wide color gamut, and can be produced in fairly large sizes, up to 262 cm (103 inches) diagonally. They have a very low-luminance "dark-room" black level, creating a black some find more desirable for watching movies. The display panel is only about 6 cm (2½ inches) thick, while the total thickness, including electronics, is less than 10 cm (4 inches).

 
by Dinesh Thakur Category: Graphics Devices

LCD stands for liquid crystal display. Your digital watch uses an LCD to show you the time, and most portable computers use an LCD to display the screen. There is actually a liquid compound, liquid crystals, sandwiched between two grids of electrodes. The electrodes can selectively turn on the different cells or pixels in the grid to create the image you see.

 
by Dinesh Thakur Category: Graphics Devices

In a standard television-like computer monitor, an image is produced on the screen by a beam of electrons sweeping rapidly across the surface of the picture tube, lighting up the screen as it passes. Starting at the top, the beam traces one horizontal row across the screen, shifts down a bit and does another row, and so on, until the full height of the screen has been covered.



 
by Dinesh Thakur Category: Graphics Devices

In Shadow Mask CRT tiny holes in a metal plate separate the colored phosphors in the layer behind the front glass of the screen. The holes are placed in a manner ensuring that electrons from each of the tube's three cathode guns reach only the appropriately-colored phosphors on the display. All three beams pass through the same holes in the mask, but the angle of approach is different for each gun.

 
by Dinesh Thakur Category: Graphics Devices

VGA, which stands for video graphics array, is currently the most popular standard for PC screen display equipment. Technically, a VGA is a type of video adapter (circuitry in the computer that controls the screen). IBM developed the VGA for its PS/2 line of computers (the name "Video Graphics Array" is an IBM trademark), but loads of other manufacturers make VGA add-in boards (that plug into a slot in the pc) and VGA chips (in some pcs, these VGA chips are built right into the main part of the computer, the motherboard). A VGA monitor is a monitor that works with a VGA adapter.



 
by Dinesh Thakur Category: Graphics Devices

CGA stands for color graphics adapter, the first IBM video card to permit graphics on the screen. We're lucky they've come out with better models, because CGA graphics are gawdawful crude. With a CGA, your screen can show up to 640 dots across by 200 dots up and down, with only one color. Even at that maximum resolution, pictures look really blocky and out of proportion. Pictures will look even more blocky if you want 4 colors on the screen at once, since you're then limited to 320 dots across and 200 down. If you can tolerate a totally chunky display of 160 by 200 dots, you can get a maximum of 16 colors on a CGA. Wow!

 
by Dinesh Thakur Category: Graphics Devices

LED stands for light emitting diode. You know those little lights on your computer, usually near the hard disk, that flash while the computer is working? Those are LEDs. They work on the principle of electroluminescence, which refers to substances that glow when you apply electricity. LEDs were used in digital watches, but now all digital watches use LCDs because LCD stakes less power.



 
by Dinesh Thakur Category: Graphics Devices

Monitor is another word for the computer screen. But "monitor" encompasses the whole piece of equipment, rather than just the screen part that you look at. You also might hear a monitor called a display, as in "Oooh, I got a new two-page display," or VDT(video display terminal), as in newspaper journalism, or CRT (cathode ray tube), which is the technical term for a picture tube. However, flat panel screens like LCDS are not referred to as monitors, even if they're housed externally from a computer.



 
by Dinesh Thakur Category: Graphics Devices

There are used for erasable disks. MO system includes basic principles of both magnetic & optical storage systems. MO systems write magnetically & read optically. It has two standard forms : 5.25 inches & 3.5 inches.

 
by Dinesh Thakur Category: Graphics Devices

The dot pitch of a color monitor measures the size of the tiny individual dots of phosphorescent material that coat the back side of the picture tube's face. The dot pitch helps determine how sharp the image looks, independent of the resolution (which is measured in pixels). A smaller dot pitch is better.

 
by Dinesh Thakur Category: Graphics Devices

Vector graphics are stored in the computer as a set of mathematical formulas describing the shapes that make up each image. When you display a vector graphic on the screen or print it, these formulas are converted into the patterns of dots you can see. Because the dots are not specified unit! you display or print the graphic, you can change the size of the image without any loss of quality, and the image will always appear at the highest resolution of whatever screen or printer you're using. The term vector graphics means exactly the same thing as object-oriented (or just object) graphics.



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.