Continuous tone
Encyclopedia
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 halftone
s, such as one single color for monochromatic prints, or a combination of halftones for color prints.
The most common continuous tone images are digital photograph
s. 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.
Halftone
Halftone is the reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size, in shape or in spacing...
s, such as one single color for monochromatic prints, or a combination of halftones for color prints.
The most common continuous tone images are digital photograph
Photograph
A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...
s. 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
Gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain complete subset of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circumstance, such as within a given color space or by a...
.
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.