Introduction to Computer Graphics
CG (computer
graphics) is a term which brings multiple applications together, for designing
and exporting an image, audio & video production and presentation for Televisions,
Web & Print media.
Types of CG:
We can categorize
computer graphics into two parts.
1: Raster or
bitmap graphics.
2: Vector
graphics
Images can be taken from
cameras, scanners or other sources like websites etc.
Digital images include both vector images and raster images, but raster images
are more commonly used.
Raster
Graphics
A picture is
good example of raster graphics. There are small color dots which compiled
together to form an image. These tiny color dots are called “Color Pixels”. When
you are going to work on raster graphics its means you are going to edit an
image. Raster graphics can be edited by erasing or changing the color of
individual pixels using program software.
.
Resolution of Image
Resolution depends
on measuring size and quantity of color pixels in an image. Total number of
pixels present in 1 square inch is called Resolution of an image. Some other measuring
units are also available in designing applications like, picas, points, millimeters,
etc. you can change these measuring units according to your need.
Resolution
of image depends that what you are going to design for, for example if you are
editing or designing an image for web its resolution could be like 100 pixel
per square inch, and if you are producing an image for printing it’s resolution
could be up to 300 Pixels per inch for sharp and better result. Low resolution
could distort the color information of image causing dull and blur print in the
end.
Big
resolution will require more offline storage space. Its means that with
increasing the resolution it will also increase file size. So be careful when
you are going to export an image from any designing application, that its
resolution and size should be perfect according to your need.
We can edit
photographs and add various effects, themes and text with the help of tools in
software programs.
*Adobe Photoshop,
Corel photo paint & U Lead photo impact are well known professional
software based on raster graphics by default and RGB color system. But we can
also work on vector and CMYK color system.
Vector Graphics
Vector
graphics depends on dimensions. Vector graphics are comprised of paths.
A path can be a line, a triangle, or any kind of shape. These paths can be used
to create simple drawings or complex diagrams.
Draw a horizontal line and represent it with “X”, again draw
a vertical line represent with “Y” on a graph chart. It shows 2 dimensions or
coordinates of vector graphics. A rectangle has two “x” & two “y”
coordinates. Or we can say that by joining 2 ‘x’ and 2 ‘y’ coordinates together,
we can draw a rectangle.
In 3D “Z” coordinate represents third dimension.
Because vector-based
images are not made up of a specific number of color dots (pixels), they can be
scaled to a larger size and by doing this they do not lose any image quality. This
makes vector graphics ideal for logos, which can be small enough to appear on a
business card, but can also be scaled to fill a billboard.
We can fill vector shapes with multi colors, patterns &
textures. Examples of drawing or creating brochures, visiting cards, designs
for billboards, office stationary and other printing art works are common
examples of vector based designing.
*Adobe illustrator,
Corel Draw & Macromedia freehand is well known professional software based
on vector graphics by default and CMYK color system. But we can also work on raster
and RGB color system.
Saving projects in different software program will save this
file in relevant software’s extension, for example, when we save an adobe Photoshop’s
file naming “my pic”. The file would be saving with the software extension “.psd”.
(my pic.psd).Every software has its own extension like Corel Draw’s file
extension is “.cdr”.
Uncompressed and
compressed file
When you are working
in software program, in fact you are working with uncompressed file format. After
completion of art work it will be export in a form of compress file format. Well
known image compressors are, JPEG (joint picture expert group), PNG (portable
net graphics), BMP (bitmap) and Gif. These compressors have color information
of 24bit (8 bit color information for each one among three main colors). Uncompressed
image formats are also used for storing transparency in an image. Some of the
examples are “TGA (targa)”, “TIF (true image font)”, and EPS (encapsulated
postscript file).
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nice working bhai
Thanks Dear Syed Nasar. also waiting for suggestions. :)
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