Types of Graphics

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).