What Is Dithered Color?
| Dithered Colors |
| Dithering, also called Halftoning or Color Reduction, is the process of rendering an image on a display device with fewer colors than are in the images. The number of different colors in an image or on a device is used called its Color Resolution. The term 'resolution' means 'fineness' and is used to describe the level of detail in a digitally sampled signal. It is used most often in referring to the Spatial Resolution, which is the basic sampling rate for digitized images. To give the appearance of more colors, and this is especially true of early monitors that could only display 16 pure colors, a process called dithering was used to give the impression of more colors. When you create an image or text images that will contain an invisible background color, make the background color the same as your web site (which should be a Web Safe color). Or, pick a Web Safe color that comes very close to your background color or background texture. The reason for this is when your application creates the web image, often it will anti-alias (blend) the edge of the visible image to the background color. If you use a white background, for example, and your site has a red brown background, you may see an annoying light colored fringe around your image. Using a Web Safe color, on the other hand, should produce a cleaner image. It is important to emphasize here that dithering is a one-way operation. Once an image has been dithered, although it may look like a good reproduction of the original, information is permanently lost. Many image processing functions fail on dithered images. For these reasons, dithering must be considered only as a way to produce an image on hardware at would otherwise be incapable of displaying it. The data representing an image should always be kept in full detail. |
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