Raster graphics

The smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for red, green and blue.

In computer graphics and digital photography, a raster graphic represents a two-dimensional picture as a rectangular matrix or grid of pixels, viewable via a computer display, paper, or other display medium. A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel.^{[citation needed]} Raster images are stored in image files with varying dissemination, production, generation, and acquisition formats.

The printing and prepress industries know raster graphics as contones (from continuous tones). In contrast, line art is usually implemented as vector graphics in digital systems.^[1]

Transposing an image to covert raster organization (a relatively costly operation for packed formats with less than a byte per pixel); composing an additional raster line reflection (almost free), either before or afterwards, amounts to a 90° image rotation in one direction or the other.

Many raster manipulations map directly onto the mathematical formalisms of linear algebra, where mathematical objects of matrix structure are of central concern.

^ "Patent US6469805 – Post raster-image processing controls for digital color image printing". Google.nl. Archived from the original on 5 December 2014. Retrieved 30 November 2014.

[1] "Patent US6469805 – Post raster-image processing controls for digital color image printing". Google.nl. Archived from the original on 5 December 2014. Retrieved 30 November 2014.

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