Understanding Computer Graphics Formats
By David Manson
Computer graphics can add life to any project but using the wrong format can
mean that you could end up with a poor quality image or large file. Computer
store images in different ways, as a bitmap where image information are stored
in pixels or as a vector format where image information is stored in the form
complex mathematical formula.
So let's first look at pixel format, a picture in this format can be broken
down into thousands of tiny blocks called pixel. Each pixel stores information
like color and brightness, when you open a image file thousands of these pixel
align themselves to give you the final picture. Most common pixel formats are
JPG, GIF, BMP, TIFF etc.
In pixel formats, if you want a highly detailed image which directly
increases the image file size - also when you zoom into pixel graphics you will
notice jagged edges (pixels) which affects the appearance of the image.
Vector graphics on the other hand do not face these issues. In a vector
format, an image is created mathematically by describing the position, length,
direction and color of all lines, which collectively form the final image. The
advantage of vector graphics is that it offers superior image quality. some of
the popular vector formats in CDR (CorelDraw), AI (Adobe Illustrator), WMF
(Windows Meta File) etc. One of the biggest drawbacks of vector images is that
they are not photo realistic, pixel format are preferred for photo realistic
Color depth of an image determines quality and richness of the image. Color
depth are coded at 8-bit (256 colors), 16-bit (65,536 colors) and 24-bit (16.7
million colors). 24 bit images offer true to life quality on the images as it
supports and displays millions of colors. Although would need a good graphics
card to view at 24-bit which most computers today are easily able to display.
What are web safe colors? In simple terms, a web safe color can defined as a
color that appears the same in all web browsers on both Windows and Mac
computers. In HTML, colors are expressed either as hexadecimal values (for
example, #FF0000) or as name of color (red, green, blue etc). During advent of
Internet – computers and web browsers would display in 8-bit mode (256 colors
supported) , but today all computers are able to display at 16-bit or 32-bit
colors which is millions of colors. It is not critical anymore to use a browser
safe color palette especially if you are targeted today’s computers as your
audience. However do not forget that there are other ways to access internet
through devices such as PDA’s and Cell phones which still continue to display at
So if you have a website or plan on a website where appearance of colors are
critical you should play safe by using web safe color palette – there are 216
common colors that are web safe.
Images play a very important role in the look and feel of a web page or
website. Good use of colors & images can boost the performance of your website,
establish credibility and comfort for the user, but more importantly convey
message of your product or services but here are few web design tips.
- Internet Speed - Faster the Internet connection faster the users will be
able to see your website. It is always a good practice to design for dial-up
- Relevance - Faster is better! People start getting impatient if it takes
longer than 30 seconds to download your page and its graphics.
- Simple - Keep web page interface simple and easy to navigate and read
text. Avoid flashy animations and bright colors