Determining ideal image format

To determine your ideal image format, consider how your image is going to be used (for example, in Web or Print form) and what type of image it is (flat color vs. continuous tone). It's best to save images with large areas of flat color as GIF or PNG-8 images. Save other images, such as those with color gradients or other continuous tones, as JPEG or PNG-24 files.

Another consideration is where the image will be viewed. The WBMP format, for example, is specifically designed for display on mobile devices.