Raster Graphics
In computer graphics, a raster graphics or bitmap image is a dot matrix data structure that represents a generally rectangular grid of pixels (points of color), viewable via a monitor, paper, or another display medium. Raster images are stored in image files with varying formats.
A bitmap is a rectangular grid of pixels, with each pixel's color being specified by a number of bits.[1] A bitmap might be created for storage in the display's video memory[2] or as a device-independent bitmap file.[1] A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel (or color depth, which determines the number of colors it can represent).[1]
The printing and prepress industries know raster graphics as contones (from "continuous tones"). The opposite to contones is "linework", usually implemented as vector graphics in digital systems.[3] Vector images can be rasterized (converted into pixels), and raster images vectorized (raster images converted into vector graphics), by software. In both cases, some information is lost, although certain vectorization operations can recreate salient information, as in the case of optical character recognition.
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