1. Basic Terminology BIT DEPTH is determined by the number of
bits used to define each pixel. The greater the bit depth, the
greater the number of tones (grayscale or color) that can be
represented. Digital images may be produced in black and white
(bitonal), grayscale, or color. A bitonal image is represented
by pixels consisting of 1 bit each, which can represent two
tones (typically black and white), using the values 0 for black
and 1 for white or vice versa. A grayscale image is composed of
pixels represented by multiple bits of information, typically
ranging from 2 to 8 bits or more. A color image is typically
represented by a bit depth ranging from 8 to 24 or higher. With
a 24-bit image, the bits are often divided into three groupings:
8 for red, 8 for green, and 8 for blue. Combinations of those
bits are used to represent other colors. A 24-bit image offers
16.7 million (2 24 ) color values. Increasingly scanners are
capturing 10 bits or more per color channel and often outputting
8 bits to compensate