Web graphics include both static images and animated web graphics. These graphics can consist of web buttons used on menus, background images on websites, web slideshows and single images displayed on a page. Some common formats for web graphics include Joint Photographic Experts Group (JPEG) files, portable network graphic (PNG) files, tagged image file format (TIFF) files, bitmap picture (BMP) files and graphics interchange format (GIF) files. The type of graphic format used is determined by the intended use of the specific graphic.
One of the most popular static formats for web graphics is JPEG. This format supports compression that helps make graphics load faster on a slower Internet connection. Th JPEG format does have a drawback, though, because images lose some of their quality during the compression process. JPEG files, however, can also use a smaller amount of compression if a higher image quality is desired.
Another format that supports compression is PNG. This file format allows images to have transparent backgrounds, but some browsers might not support the PNG file type. PNG does have benefits in that these images are sharper and have more color depth than some of the other image formats. On the other hand, some web designers are still reluctant to use PNGs very much because of the possible compatibility issues with older browsers.
If an animated web graphic is desired, the GIF format is a good choice. Animated GIFs use several variations of a static image to create a motion effect. GIF images, however, do not have to be animated, and they can be used for compact static web graphics because of the smaller file size. Common uses of static GIF images includes web buttons and website backgrounds, although the JPEG and PNG formats are commonly used as well. One disadvantage of GIFs is that they are limited to 256 possible colors, which can be a problem if an image needs to have excellent color depth.
TIFF images are a higher-quality image format that is usually used for graphics that are printed. They are not used often on the web because of their large file size and limited capabilities for compression. Common uses of TIFF images includes images that are captured from a picture or document scanner and are used for printing a newsletter, poster or a magazine layout.
BMP images are more common than TIFF images but also have issues with file size. They are uncompressed images that suffer no loss in quality. As a result, BMPs are useful when a web designer wants to put high-quality images on a site but does not want the long download times associated with TIFF files.