Many applications need to work with a variety of scanners, and each scanner may have either slightly or vastly different capabilities. For example, the scanner may have only a flatbed, only a document feeder, or both flatbed and feeder. It may be a binary-only scanner, a grayscale scanner, or a color scanner. In addition to these basic features, various scanners have different levels of extra features, such as automatic brightness and contrast control, bar code readers, endorsers, downloadable dither and gamma settings, and so forth.