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4.4 Web graphic formats
The three most popular graphic formats that can be viewed by browsers are:
  1. GIF - Graphics Interchange Format: A patented file format that supports 256 (8 bit) colors and is generally used for a wide range of graphics. GIF has three major features that make it popular.
    1. Interlacing is a method of storing the image so that when it is displayed, its quality is improved by several passes. The user gets an idea of the contents of the image before the entire image has been constructed. The images appears in several steps.
    1. Transparency You can designate one color of the image as transparent. The text or images that are on the page beneath the GIF will be visible
    1. Animation A sequence of GIFs, or portions of images, can be stored. The browser will then display these images in sequence, creating a moving image.
  1. JPEG or JPG - Joint Photographic Experts Group: Is patent-free file format that supports 16 million (24 bit) color. It is generally used for high resolution graphics like photographs.
  1. PNG - Portable Network Graphics: Provides a patent-free replacement for GIF. It supports many colors and is generally used for a wide range of graphics. The PNG format can also be used to save photographs.
    1. Please note, PNG support requires browsers later than 4.1.
It's True! It's True! Higher numbers of colors and greater resolution for a file mean a better looking display, but also a larger the file size (so it will take longer to download.)