Image file formats on the web

25 March, 2010

• design
• file formats
• images

Ismail Koci

Category: Web Design

There are a vast array of file formats on the web. Some of the formats you may be more familiar with are the main image formats of JPEG, GIF, and PNG.

Below is a brief run down on what these file formats are, and what separates them from each other.

JPEG

This is perhaps the most common format on the web and stands for "Joint Photographic Experts Group." JPEG's are most commonly used for photographs and images with lots of colours.

The majority of photographs on the web are in this format because it offers high image quality for a relatively low file size. Of course this quality and file size differs depending on how much fidelity a designer decides to save it with.

GIF

GIF stands for Graphics Interchange Format. They are "loss-less" which means unlike JPEG's the image is not compressed. However, they have only 256 colours, which means that on the internet of today they have a specific purpose.

That purpose is mostly being used for very simple images with large blocks of solid colours rather than gradients. Another fantastic thing about GIF's is that they allow for single-bit transparency, which means parts of an image that are a particular selected colour can be see-through.

PNG

This is the relative new comer to the scene and stands for "Portable Network Graphics." Just like GIF it is loss-less but the great thing about PNG's is that they offer a much higher quality with more colours as well as alpha channels (better transparency than GIF).

This transparency option is what truly sets it apart from the others. In a GIF image, a pixel is either fully transparent or it isn't transparent at all. PNG's however offer the option to make pixels partly transparent which means that images have a smoother, higher quality appearance.

Conclusion

So there you have it. A brief run down of the main image formats on the web. If you have any questions don't hesitate to leave a comment and I'll be happy to answer it.