text: 2.what is a raster scan system? what is a picture element & how it is represented?   raster scan, or raster scanning: is the pattern of image detection and reconstruction in television, and is the pattern of image storage and transmission used in most computer image systems. the word raster comes from the latin word for a rake, as the pattern left by a rake resembles the parallel lines of a scanning raster.  picture element: in a raster scan, an image is cut up into successive samples called pixels, or picture elements, along scan lines. each scan line can be transmitted as it is read from the detector, as in television systems, or can be stored as a row of pixel values in an array in a computer system. on a television receiver or computer monitor, the scan line is turned back to a line across an image, in the same order. after each scan line, the position of the scan line is advanced, typically downward across the image in a process known as vertical scanning, and a next scan line is detected, transmitted, stored, retrieved, or displayed. this ordering of pixels by rows is known as raster order, or raster scan order.