Digital Prints

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Mastering Digital Printing
Digital Equivalents
8 bits=1 byte
1024* bytes=1 kilobyte (KB)
1024 kilobytes=1 megabyte (MB)
1024 megabytes=1 gigabyte (GB)
1024 gigabytes=1 terabyte (TB)
*it’s 1024 and not 1000 because of the way the binary system works with its powers of two—in this case, 210 .
So far, we’ve only talked about bits in terms of black, white, or gray. Since most people
work in color, you now have to apply the same thinking to each color component of the
image. So, in a 24-bit (8 bits per color) RGB image, there are 256 possible values of Red,
256 of Green, and 256 of Blue, for a grand total of—are you ready?—16,777,216 possible
values, tones, or colors for each pixel (see Figure 2.4). A CMYK color image is described
as 32-bit, or one 8-bit channel for each of the four printing colors: cyan, magenta, yellow,
and black or “K.” There is no more color information with CMYK; it’s just allocated
differently than RGB. (For more about color and color models, see Chapter 4.)
R G B
Whether an image has one, two, four, eight, or even more bits of information per pixel per
color determines its bit depth. The higher the bit depth, the more detailed and realistic the
image. (You don’t have to stop at 8 bits. Current input technology allows for up to 16 bits
of information per channel—see Chapter 3 for the pluses and minuses of going “high-bit”.)
Figure 2.4 Color bit depth.