Page 24 - DCAP313_LAB_ON_COMPUTER_GRAPHICS

Lab on Computer Graphics

Notes abstract and tangible ideas. Visualization today has ever-expanding applications in science,
education, engineering (e.g., product visualization), interactive multimedia, medicine, etc.
Typical visualization application is the field of computer graphics. The invention of computer
graphics may be the most important development in visualization since the invention of central
perspective. The use of visualization to present information is not a new phenomenon. It has
been used in maps, scientific drawings, and data plots for over a thousand years. Computer
graphics has from its beginning been used to study scientific problems.

Most people are familiar with the digital animations produced to present meteorological data
during weather reports on television, though few can distinguish between those models of
certainty and the satellite photos that are also shown on such programs. TV also proposes
scientific visualizations when it shows computer drawn and animated restorations of road or
airplane accidents. Some of the most popular examples of scientific visualizations are: computer-
generated images that show real spacecraft in action, out in the void far beyond Earth, or on
other planets. Dynamic forms of visualization, such as educational animation or timelines, have
the potential to enhance learning about systems that change over time.
Apart from the distinction between interactive visualizations and animation, the most useful
categorization is probably between abstract and model-based scientific visualizations. Data
visualization is a related subcategory of visualization dealing with statistical graphics and
geographic or spatial data (as in thematic cartography) that is abstracted in schematic form.
2.1.1 Scientific Visualization

Scientific visualization is the transformation, selection, or representation of data from simulations
or experiments, with an implicit or explicit geometric arrangement, to allow the examination,
analysis, and understanding of the data. Traditional areas of scientific visualization are flow
visualization, medical visualization, astrophysical visualization, and chemical visualization.
There are several different techniques to visualize scientific data, with surface reconstruction
and direct volume rendering being the more common.

2.2 Video Display Devices

The display devices are known as output devices. The most commonly used output device in
a graphics video monitor. The operations of most video monitors are based on the standard
cathode-ray-tube (CRT) design. How the Interactive Graphics display works the modern graphics
display is really easy in creation.
It consists of three components:
• A digital memory, or frame buffer, in which the displayed Image is stored as a matrix of
intensity values.
• A monitor.

• A display regulator which is a simple interface that passes the contents of the frame buffer
to the monitor. Inside the frame buffer the image is stored as a pattern of binary digital
numbers, which represent a rectangular array of picture components, or pixel. The pixel
is the smallest addressable screen element. In the Simplest case where we wish to store
only black and white images, we can characterize black pixels by 0’s in the frame buffer
and white Pixels by 1’s. The display regulator simply reads each successive byte of data
from the frame buffer and converts each 0 and 1 to the corresponding video signal. This
signal is then fed to the monitor. If we wish to change the displayed picture all we need
to do is to change of modify the frame buffer contents to represent the new pattern of
pixels.

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