Graphic Formats

Although hundreds of graphic file formats exist web browsers only support a few of them. This article describes the different graphic file formats that are available to web designers.

The graphic file formats supported by most popular web browsers are Graphic Interchange Format (GIF), Joint Photographic Experts Group (JPEG), Portable Network Graphics (PNG) and vector graphics. Some of the properties of graphic files are:

Transparency – this property allows the image to be varying degrees of transparency.
Compression – this property allows the image to be stored in a much smaller file by using a mathematical algorithm to handle groups of pixels as a single item.
Animation – Animation gives the appearance of movement by using a series of successive still pictures. Animated gifs do not require a browser plug-in and can work on almost all devices.
Progressive loading – Progressive loading loads a portion of the picture initially but is not based on alternating rows and allows the user to see the picture quicker.

GIF Advantages:

Most widely supported graphic format.
Diagrams look better in this format.
Supports transparency.

JPEG Advantages:

Large compression ration means faster download speeds.
Produces excellent quality for photographs and complex drawings.
Supports 24-bit color.

PNG Advantages:

Overcomes the 8-bit color limitation of GIF.
Allows text description of the image.
Supports transparency.
Diagrams look better than they do in JPEG.