Rasterisation is the task of taking an image described in a vector graphics format (shapes) and converting it into a raster image (pixels or dots) for output on a video display or printer, or for storage in a bitmap file format.
There are several applications of the raster and random. Such applications are common in raster scan system, raster scan generator and many more.
RASTER:-* raster display have less resolution *decrease memory cost have made raster system popular *display or capturing a video line by line Random :-* random displays have high quality resolution *random scan system's are generally much expensive
raster scan display -based on television technology.where as random scan display based on hard copy devices.raster scan display cannot directly pass electron beam through the scan line..but random scan directed the beam toward the scan line.
Define briefly raster scan system
what are the advantages of randon scan and raster scan? what is flat panel display
Raster-scan:-q1) Raster displays have less resolution.q2) The lines producced are ziz-zag as the plotted values are discrete.q3) High degree realism is achived in picture with the aid of advanced shading and hidden surface technique.q4) Decreasing memory costs have made raster systems popular.Random scan:-q1) Random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values.q2) Smooth lines are produced as the electron beam directly follows the line path.q3) Realism is difficult to achieve.q4) Random-scan system's are generally costlier.
Raster-scan system:-1)raster displays have less resolution. 2)the lines producced are ziz-zag as the plotted values are discrete.3)high degree realism is achived in picture with the aid of advanced shading and hidden surface technique.4)decreasing memory costs have made raster systems popular.Random scan system:-1)random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values. 2)smooth lines are produced as the electron beam directly follows the line path.3)realism is difficult to achieve.4)random-scan system's are generally costlier.
Raster scan is based on television technology. In this the electron beam is swept across the screen, one row at a time 4m top to bottom, which creates a pattern of illuminated spots. When a CRT is operated as random scan display unit the electron beam directed only to the parts of the screen where a picture is to be drawn. Random scan monitors draw a picture one line at a time and for this reason are also called as vector display.
Advantages of Random scan display:1)high resolution2)produce smooth line drawings.Disadvantages of random scan display:1)costlier2)just does wire frame.3)complex scene cause visible flicker.Advantages of raster scan display:1)decreasing memory costs have made raster systems popular.2)high degree realism is achieved in picture with the aid of advanced shading and hidden surface technique.3)Computer monitors and TVs use this methodDisadvantages of Raster scan display:1)the lines produced are zigzag as the plotted values are discrete.2)resolution is low.
Raster-scan system:-1)raster displays have less resolutio. 2)the lines producced are ziz-zag as the plotted values are discrete.3)high degree realism is achived in picture with the aid of advanced shading and hidden surface technique.4)decreasing memory costs have made raster systems popular.Random scan system:-1)random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values. 2)smooth lines are produced as the electron beam directly follows the line path.3)realism is difficult to achieve.4)random-scan system's are generally costlier.
Raster-scan1)raster displays have less resolutio. 2)the lines producced are ziz-zag as the plotted values are discrete.3)high degree realism is achived in picture with the aid of advanced shading and hidden surface technique.4)decreasing memory costs have made raster systems popular.Random scan1)random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values. 2)smooth lines are produced as the electron beam directly follows the line path.3)realism is difficult to achieve.4)random-scan system's are generally costlier.
Application of Raster scan display: Basically it is used in Plotters. and mainly more like....Printers,,,,
In raster scan display, the electron beam is swept across the screen, one row at a time from top to bottom.Random scan monitors draw a picture one line at a time and so they are also referred to as vector displays.Refreshing on raster scan display is carried out at the rate of 60 to 80- frames per second. Refresh rate on a random scan system depends on the number of lines to be displayed.The picture definition is stored in a memory area called refresh buffer or frame buffer in case of a raster scan display. In case of random scan display, picture definition is stored as a set of line-drawing commands in an area of memory referred to as the refresh display file. Refresh display file is also called the display list, display program, or the refresh buffer.
example of raster scane disply
Display File is a memory area which stores picture definition as a set of line drawing commands.Video controller interprets these commands and produces actual image on the screen.Display File in random scan system is comparable to frame buffer in raster scan system, on the basis of their functions.
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.
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.
In Raster scan display electron beam swept across the screen one row at a time from top to bottom.when reaches the bottom scan starts again from top.It produce a zig zag lines.
Raster-scan system:-1)raster displays have less resolution.2)the lines produced are ziz-zag as the plotted values are discrete.3)high degree realism is achived in picture with the aid of advanced shading and hidden surface technique.4)decreasing memory costs have made raster systems popular.5)In this case, the electron beam is swept across the screen, one row at a time from top to bottom.6)Picture definition is stored in a memory area called the refresh buffer/frame buffer.7)Refreshing on raster scan displays is carried out at the rate of 60 to 80 frames/second. Random scan system:-1)random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values.2)smooth lines are produced as the electron beam directly follows the line path.3)realism is difficult to achieve.4)random-scan system's are generally costlier.5)Here CRT has the electron beam directly only to the parts of the screen where a picture is to be drawn.6)Picture definition is stored as a set of line drawing commands in an area of memory referred to as refresh display file.7)Random scan systems are designed to draw all the component lines of a picture 30 to 60 times each second.
Raster-scan system:-1)raster displays have less resolution. 2)the lines produced are ziz-zag as the plotted values are discrete.3)high degree realism is achived in picture with the aid of advanced shading and hidden surface technique.4)decreasing memory costs have made raster systems popular.5)In this case, the electron beam is swept across the screen, one row at a time from top to bottom.6)Picture definition is stored in a memory area called the refresh buffer/frame buffer.7)Refreshing on raster scan displays is carried out at the rate of 60 to 80 frames/second.Random scan system:-1)random displays have high resolutions since the picture definition is stored as a set of line drawing commands and not as a set of intensity values. 2)smooth lines are produced as the electron beam directly follows the line path.3)realism is difficult to achieve.4)random-scan system's are generally costlier.5)Here CRT has the electron beam directly only to the parts of the screen where a picture is to be drawn.6)Picture definition is stored as a set of line drawing commands in an area of memory referred to as refresh display file.7)Random scan systems are designed to draw all the component lines of a picture 30 to 60 times each second.
plen plotter is most example of random scan display
Raster graphics is a way of storing graphical information (see related link). Random refers to a complete lack of order or relationships between values or events. Small random disturbances in acoustics is referred to as noise. See related link.
The file size is normally smaller than raster.
Ability to store the intensity value of all the spotted lights...
He invented the first practical television system with a raster scan inspired by his plowing of a field.