What is raster scanning?

Raster scanning is a method of image construction using horizontal lines. The lines can be an analog representation of the image, or they can be a sequence of pixels in which each dot represents a small rectangular area of ​​the image. One of the primary applications of raster scanning technology was in traditional imaging devices such as TVs or computer monitors. Some computer printers also use raster scan methods to design images on paper. Most digital images are also stored and reconstructed using raster scan techniques. The line returns to the left side, falls a small amount down and draws another line of the picture. When the beam that draws the image reaches the lower right corner of the screen, the effectively indicated image has been rendered, moves back to the upper left corner to start again, which is known as vertical repetitions. This process occurs several times every second to create a smooth moving image.

Although raster scanning is capable of creating a very realistic image, the real process creates a minute of almost unnoticed distortion in the picture. At the end of each horizontal line, the beam must return to the left side of the screen called a check or horizontal repetition. This is achieved most efficiently by really drawing every visible line by slight slope down towards the lower right screen. In this way, during the horizontal repetition, the beam moves back in an almost straight horizontal line. Although it is the fastest way to draw a picture, in fact it is excellent at a very small angle.

Computer software that digitally stores images, uses a similar technique to coding information and then decompress it. The raster scan of the image begins in the upper left corner of the picture and proceeds in the same way towards the bottom right. BowlHowever, the imposition of a variety of analog information is converted into small rectangles called pixels that can be set to one color. The pixel collection in horizontal parts forms a picture not only in the file encoding, but also in the computer memory when the image is shown.