Computer graphics

Computer graphics, that is, all images created with computers can be divided into two classes - raster and vector. Programs that create and process these images on the monitor screen are called computer graphics systems.

Computer graphics, that is, all images created with computers can be divided into two classes - raster and vector

Raster computer graphics are described by the specific arrangement and color of points (pixels) tied to the grid (raster), i.e. the image is created as in a mosaic. The image is visually better when there are many dots and they are small. In addition, the quality is also characterized by the number of colors and shades that each point of the image can take. Unfortunately, scaling in either direction usually degrades the quality. With a reduction in the number of points, small details are lost and the inscriptions are deformed. In accordance with the resolution, i.e. the number of points per unit length, the same picture can be represented with better or worse quality. Resolution is usually measured in dots per inch - dpi or in pixels per inch - pði. Currently, the following raster graphics formats are common: .bmp, .ðñõ, .gif, .tif, .jpg, etc.

Vector computer graphics are described using curved lines called vectors, as well as parameters that describe their colors and location. For example, the image of a figure on the monitor is described by the points through which the contour line of the figure passes. The color of the shape is specified by the color of the outline and the color of the area inside this outline.

When editing vector graphics elements, you can change the parameters of lines, transfer them, change the size, shape, color, but this will not affect the quality of their visual presentation. Vector graphics do not depend on resolution, i.e. can be displayed in a variety of output devices with different resolutions without loss of quality. Another advantage is quality scaling in any direction. But vector computer graphics becomes unprofitable when you transfer images with a large number of tints or small details. In this case, every minute glare will not be represented by a set of monochrome points, but by the equation of a line. This results in an increase in the files.

Thus, if photographic color accuracy is required, then raster computer graphics are preferable. Logos and diagrams are more conveniently represented using vector computer graphics. It is clear that regardless of the presentation, the computer graphics (like the text) are displayed on the screen of the monitor or the printing device in the form of a set of points. In the Internet, computer graphics are presented in one of the raster formats - GIF, JPG, PNG.

Depending on what kind of computer graphics are used, for each type you have to use a separate graphic editor - raster or vector. Therefore, the principles of implementing the drawing and editing processes are different and are conditioned by the nature of the corresponding format. So, if in raster editors they speak about the selection of an object, they mean a set of points in the form of a domain of complex shape. In the vector editor, the object represents a collection of graphic primitives, and for its selection it is enough to select each of them by the mouse.

There is a tendency to bring together the editors of vector and raster computer graphics. Most modern vector editors are able to use raster images as a background, and even translate part of the image into a vector format.

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