Computer icons are an integral part of any modern GUI. Icons are small pictures of standard resolutions that visually represent objects, actions, and other concepts. In graphical user interfaces, icons are used as a faster, more intuitive way to communicate with the user. Icons representing standard elements of a user interface are better visible than text, can be recognized faster, and are easier for new computer users.
Originally developed in 1970 by the Xerox Research Center and widely popularized by the Mac OS and Microsoft Windows systems, icons make new users feel more comfortable with computer systems, learn faster and interact more efficiently. Icons can be employed to replace or supplement text messages. Commonly used in menus, toolbars, on buttons and in new ribbon-style user interfaces, icons have come a long way from the original concept.
There are several graphic formats for storing icons. The Windows systems use Windows icons in the platform-specific ICO format. Apple Macintosh computers use Mac icons in their specific formats, while Unix-based systems use PNG icons for most applications. As such, icon software is generally available for the Windows and Apple platforms, while Unix users can design their icons with any graphic editor.
Generally speaking, icons are square pictograms that come in a variety of standard sizes and color resolutions. Most systems use icon sizes of 16×16 to 128×128 pixels, while some platforms readily accept icon images as large as 512×512 pixels. The large 512×512 pixel icons were first employed in Mac OS Leopard.
Pixel resolutions of all icons are operating system dependent. For example, Windows icons are defined as pictures in 16 and 256-color gammas as well as True Color pictures with alpha channel. Windows icons are supplied in standard sizes of 16×16, 32×32, and 48×48 pixels. Windows Vista implements new standards for Windows icons, including icons in sizes of up to 256×256 pixels in True Color only. Optionally, icons of 128×128 and 512×512 pixels are supported. Interestingly, the higher resolution versions of Windows Vista icons are stored in compressed PNG format instead of Windows ICO used in older versions of Windows and for lower resolution icons. Other platforms such as Windows Mobile can use standard icons of other sizes, such as 24×24 pixels.
Numerous independent vendors are providing custom icons. Aha-Soft offers a variety of Windows icons, Mac icons, and PNG icons in all sizes and resolutions common to those platforms. The company provides royalty-free icons individually and in matching sets incorporating icons drawn a common style or theme.