Web design image formats - an introduction

When browsing the internet you are likely to come across many different image formats. However, the most common formats are: CompuServe GIF, JPEG, and Bitmaps.

CompuServe GIF

GIF stands for Graphic Interchange Format and was standardized by CompuServe in 1987. The very first GIF format was GIF87a and saves images at 8 pits-per-pixel with a colour level of 256. Then in 1989 CompuServe updated the GIF format to include animation, transparency, and interlacing, which was called GIF89a. Apart from animation, transparency, and interlacing there is little difference between to two.

JPEG

The JPEG image format was developed by Joint Photographic Experts Group. JPEG's best feature is the compression, you can compact the image file to make it the size smaller (bytes). The problem with this format is that there is a trade-off details detail and size. Generally its best to save JPEG's at 50% compression.

Bitmaps

Bitmaps was invented by Microsoft (everyone's favourite company). The Bitmap format saves your image pixel for pixel, in other words, what ever you see on the screen before you save is what you see when you open the image again. The only drawback is that the file sizes can be extremely large, which may result in longer download/upload times

Wrtten by Stephen Hames who runs a web template site at http://www.sjh-designs.co.uk