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Unformatted text preview: uce the storage
requirement, images are usually compressed before being stored or transmitted.
Image compression techniques are discussed later in this chapter.
The area of computer graphics that deals with this type of pictures is known as
cognitive graphics. Cognitive graphics along with image processing techniques
(like image compression and decompression, cleaning of noisy or blurred images,
image editing, etc.) is extensively used in applications that deal with recognition
and classification of pictures. For example, an image database containing images
of peoples' fingerprints is commonly used nowadays in criminal investigation.
Another similar application is classification of images of ECG patterns, X-rays of
different parts of the body, etc. to perform medical diagnosis of patients by using
Hardware Requirements for Graphics
Computer graphics generally involves the following hardware devices (see
Chapter 9 for a description of some of these I/O devices):
1. A locating device (such as a mouse, a joystick, or a stylus) attached to a video
display terminal along with a drawing software is often used to directly draw
pictures on computer screen from scratch for generative graphics applications.
2. A flatbed or rectangular-coordinate digitizer is also used as an input device for
generative graphics applications for inputting existing line drawings (such as a
map) to a computer.
3. Scanners (optical scanners, image-scan digitizers, etc.) are most commonly
used as input devices for capturing photographs and drawings as digital images for
cognitive graphics applications.
Digital images are also captured directly by a digital camera or a frame
capture hardware such as a video capture board interfaced to some standard video
source like video camera or video cassette recorder (VCR).
Computer screens with graphics display capability are used to display
graphics. Standard VGA (Video Graphics Array) graphics can display 640 pixels
across and 480 pixels down (referred to as having a...
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This document was uploaded on 04/07/2014.
- Spring '14