A continuous tone image is one where each color at any point in the image is reproduced as a single tone, and not as discrete halftones, such as one single color for monochromatic prints, or a combination of halftones for color prints.
The most common continuous tone images are digital photographs. Film is a halftone medium.
An example of a continuous-tone device is a CRT computer screen. Here, any pixel can represent any color, because the color components of the pixel are analog and can vary in infinite steps, and hence do not need halftones to make the colors. Of course, because the computer is a digital device, it cannot provide the CRT with infinite tone variations. In 24-bit color mode, it provides the monitor with 256 discrete steps for each color, for a total of 16,777,216 discrete colors. A purely analog video signal (one that has not been manipulated by a computer of any kind) can provide infinite tone variations inside its own gamut.
A halftone device, in contrast, uses discrete dots of color, which at a certain distance look closely like the intended color. Examples of this are inkjet printers. Magazines and most printed material also use this technique to create the colors.
Famous quotes containing the words continuous and/or tone:
“Perhaps when distant people on other planets pick up some wave-length of ours all they hear is a continuous scream.”
—Iris Murdoch (b. 1919)
“There was about all the Romans a heroic tone peculiar to ancient life. Their virtues were great and noble, and these virtues made them great and noble. They possessed a natural majesty that was not put on and taken off at pleasure, as was that of certain eastern monarchs when they put on or took off their garments of Tyrian dye. It is hoped that this is not wholly lost from the world, although the sense of earthly vanity inculcated by Christianity may have swallowed it up in humility.”
—Herman Melville (1819–1891)