The aim of the work described in this report has been to apply random scan display. Raster scan system vs random scan system student study hub. Graphics commands in the program are translated by the graphics package into a display file stored in the system memory. Difference between raster scan system and random scan system base of difference raster. For the love of physics walter lewin may 16, 2011 duration. Raster can be explained as a rectangular collection of dots or points plotted. Cs3162 introduction to computer graphics helena wong, 2000 4 2. Computer graphics solved mcqs computer science solved mcqs. Computer graphics image is made up of number of pixels.
Raster scan in a raster scan system, the electron beam is swept across the screen, one row at a time. A rasterscan video graphics display system implemented. These are used to project or exhibit softcopy information in the form of alphanumeric or graphic symbology. Difference between raster scan system and random scan. In this tutorial, we are going to learn about the raster scan and random scan display in computer graphics, these scanning methods, and we will also learn each of them in detail. Architecture of raster scan devices and functions of trackball architecture trackball in a raster scan display, the image which has to be displayed is saved in a binary format 0s and 1s in the refresh buffer memory. Information of on and off pixels is stored in refresh buffer or frame buffer. Raster scan systemaddition to the cpu, special purpose processor, video controller or display controller is used to control the operation of the display device. Raster scan displays the most common type of graphics monitor employing a crt is the raster scan display in a raster scan system, the electron beam is swept across the screen, one row at a time from top to bottom as the electron beam moves across each row one scan line, the beam intensity is turned on and off to create a. Computer graphics notes pdf cg notes pdf smartzworld. Frame buffer array of computer memory used to store an image to be displayed. Application areas of computer graphics, overview of graphics systems, videodisplay devices, rasterscan systems, random scan systems, graphics monitors and work stations and input devices.
It consists of display controller, cpu, video controller, refresh buffer, keyboard, mouse and crt. The computer graphics section at the national research. Raster images are stored in image files with varying formats. Introduction to graphics systems, basic elements of computer graphics, applications of computer graphics. Computer graphics is an art of drawing pictures, lines, charts, etc. Kindly go through the following key points to be noted as far as both graphics monitor and workstations are concerned.
Raster scan tracing starting at the topleft of the screen and going to the bottomright, the electron beam is turned on a line at a time 1, then turned off to go back to the next line 2, then. Shadow mask method is commonly used in rasterscan system because they produce a much wider range of colors than the beampenetration method. An application program is input and stored in the system memory along with a graphics package. Then, a video controller is used to scan each and every line. In raster scan system electron beam sweeps across the screen, from top to bottom covering one row at a time. A raster scan display is based on intensity control of pixels in the form of a rectangular box called raster on the screen. Pdf softcel an application of raster scan graphics to. In the first pass, the beam seeps across every other scan line from top to bottom.
Input devices central processing unit graphics processing unit memory frame buffer output devices 17. Shadow mask method is commonly used in raster scan system because they produce a much wider range of colors than the beampenetration method. The raster scan system is a scanning technique in which the electrons sweep from top to bottom and from left to right. Graphics systems block diagram of a crt graphics system in this context we discuss the graphics systems of raster scan devices. The electron beam is swept across the screen, one row at a time, from top to bottom. This display file is then accessed by the display processor to refresh the screen. In a rasterscan system, the electron beam is swept across the screen, one row at a time from top to bottom. We must have to consider mathematical formulae, functions to draw image.
Difference between raster scan system and random scan system base of difference raster scan system random scan system electron beam. In addition to the cpu, a special purpose processor called the video controller or display controller is. Difference between raster scan display and random scan display. Difference between raster scan and random scan compare the. It is the method of incrementally displaying a visual on a crt. A raster display system has been developed for support of a wide range of. Raster scan article about raster scan by the free dictionary. Shekhat, ce department 2160703 computer graphics raster scan display fig. Difference between random scan and raster scan display. Rasterisation or rasterization is the task of taking an image described in a vector graphics format shapes and converting it into a raster image a series of pixels, dots or lines, which, when displayed together, create the image which was represented via shapes. As it moves across each row, the beam intensity is turned on and off to create a pattern of illuminated spots.
The aim of the work described in this report has been to apply randomscan display. Difference between random scan and raster scan display with computer graphics tutorial, line generation algorithm, 2d transformation, 3d computer. Raster scan approaches to computer graphics sciencedirect. The screen is represented by a 2d array of elements. Raster scan systemaddition to the cpu, special purpose processor. Raster scan monitors draw a picture one line at a time. It consists of display controller, cpu, video controller, refresh buffer, keyboard, mouse and. In other words, we can say that computer graphics is a rendering tool for the generation and manipulation of images. Televisions in our house are based on raster scan method. Architecture of raster and random scan display devices, inputoutput devices.
Home computer graphics solved mcqs computer graphics. In stroke graphics da converters are expensive and slow, computer is overburdened with refreshing display, doesnt work with existing tvs. Graphics monitor and workstations are explained in detail. Calligraphic or random scan display system refresh and raster scan display system dvstdirect view storage tube a slow moving electron beam draw a line on the screen screen has a storage mesh in which the phosphor is embedded image is stored as a distribution of. As the electron beam moves across each row, the beam intensity is turned on and off to create a pattern of illuminated spots. A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. In a raster scan displays the electron beam is swept across the screen, one row at a time from top to bottom. The growth in the use of such methods has been dependent on rapidly decreasing memory prices and on the availability of cheap scan generating hardware from the tv industry. Raster scan line drawing algorithm, circle and ellipse drawing algorithms. Architecture of raster scan devices by palak tandon on prezi. The raster scan system can store information of each pixel position, so it is suitable. The user manipulates the values in the frame buffer. Sep 30, 20 random scan displays and raster scan displays 2. A system which follows raster scan displays is called raster scan system 2.
Pixels or points on the screen can be used to draw any kind of image 3. Contrasting in random scan displays the electron beam is directed to the parts of the screen where a picture is to be drawn. It involves computations, creation, and manipulation of data. The electron beam is directed only to the parts of screen where a picture is to be drawn. Workstation and graphics monitor in detail student study hub.
A system which follows random or vector scan displays is called random scan system. The titled plurality is justified by a generality and by a superset of degrees of freedom in the specific device, all of which no one application warrants and all of which have immense programming implications. The more general term pixmap refers to a map of pixels, where each one may store more than two colors, thus using more than one bit per pixel. Graphics systems block diagram of a crt graphics system in this context we discuss the graphics systems of rasterscan devices. The growth in the use of such methods has been dependent on rapidly decreasing memory prices and on the availability. Pdf difference between raster scan system and random scan. In a raster scan system, the electron beam is swept across. On the other hand, in the random scan, the electron beam is guided on just those regions of the screen where the picture actually lies. The intensity is turned on or off to light and unlight the pixel. Computer graphics raster scan and random scan display. Raster scan and random scan are two types of display systems that use crt monitors.
Pixel is the smallest addressable graphical unit represented on the computer screen. It is used in the majority of color tv sets and monitors. Softcel an application of raster scan graphics to conventional cel animation article pdf available in acm siggraph computer graphics 2. Sep 30, 2019 computer graphics pdf computer graphics book pdf notes starts with the topics covering introduction of computer graphics.
The name itself giving some idea that, monitor which is capable of displaying graphics. Calligraphic or random scan display system refresh and raster scan display system dvstdirect view storage tube a slow moving electron beam draw a line on the screen screen has a storage mesh in which the phosphor is embedded image is stored as a distribution of the charges on the inside surface of the screen. Raster scan displays are most common type of graphics monitor which employs crt. In computer graphics, a raster graphics or bitmap image is a dot matrix data structure that represents a generally rectangular grid of pixels points of color, viewable via a monitor, paper, or other display medium. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems. A rasterscan video graphics display system implemented on a. Difference between raster scan system and random scan system.
Computer graphics is an art of drawing pictures on computer screens with the help of programming. The beam intensity is set at high and low levels as the beam sweeps around the screen to generate a pattern of illuminated spots. A raster scan display system according to claim 1 in which said switch control means is responsive to the sensing of inequality or equality between a picture element data group in the selected stream and the data group from the data processing device to provide outputs, respectively, to cause the multiplexer to pass the picture element data group in the selected stream or the corresponding. In computer graphics, a bitmap is a mapping from some domain for example, a range of integers to bits, that is, values which are zero or one. In dot matrix raster scan graphics, lowcost ram memory and digital video logic work without any adjustment on regular television sets. Computer monitors and tvs use this method whereby electrons are beamed scanned onto the phosphor coating on the screen a line at a time from left to right starting at the topleft corner.
An image is subdivided into a sequence of usually horizontal strips known as scan lines which can be further divided into discrete pixels for processing in. In a raster scan system, the electron beam is swept across the screen, one row at a time from top to bottom. The components line of a random scan picture must be refreshed in a particular order. Raster scan displays intensity range for pixel positions depends on the capability of the raster system. Aug 01, 2018 cathode ray tube, raster scan display, random scan display, color crt monitors, dvst, flat panel displays. Flood fill scan conversion very simple more complex discrete algorithm in screen space discrete algorithm in object andor. The raster scan is a scanning technique in graphics monitor where the electron beam is moved along the screen covering one line at a time from top to bottom. Cathode ray tube, raster scan display, random scan display, color crt monitors, dvst, flat panel displays.
An image is subdivided into a sequence of usually horizontal strips known as scan lines which can be further divided into discrete pixels for processing in a computer system. Abstractthis text reports on conclusions derived from the building and use of the 85. Computer graphics pdf computer graphics book pdf notes starts with the topics covering introduction of computer graphics. Application areas of computer graphics, overview of graphics systems, videodisplay devices, raster scan systems, random scan systems, graphics monitors and work stations and input devices. Random scan monitors draw a picture one line at a time. Difference between raster scan and random scan with. Differentiate between raster and random scan displays. A shadow mask crt has 3 phosphor color dots at each pixel position. A graphics processor accepts graphics commands from the cpu and executes the graphics commands which may involve drawing into the frame buffer. System video monitor cpu memory controller system bus io devicesraster graphics system. Raster scan methods have increasingly become the dominant technology since about 1975. Random scan method is well suited for displaying shading and color areas. Its resolution is poor because raster system in contrast produces zigzag lines that are plotted as. A pattern of illuminated pattern of spots is created by turning beam intensity on and off as it moves across each row.
On some raster scan systems, each frame is displayed in two passes using an interlaced refresh procedure. Jan 17, 2019 the main difference between raster scan and random scan lies in the drawing of a picture where the raster scan points the electron beam at the whole screen but incorporating just one line at a time in the downward direction. This text reports on conclusions derived from the building and use of the 85, an elaborate raster scan display system for computer graphics applications. Computer graphics 7 there are two ways random scan and raster scan by which we can display an object on the screen. Raster scan and random scan display in computer graphics. Then after the vertical retrace, the beam sweeps out the remaining scan lines. The main difference between raster scan and random scan lies in the drawing of a picture where the raster scan points the electron beam at the whole screen but incorporating just one line at a time in the downward direction. In addition to the cpu, a special purpose processor called the video controller or display controller is used to control the operation of the display device.
1041 1049 927 168 1504 488 1108 580 557 1011 358 1159 1230 398 1135 1044 931 1054 267 1581 1043 1172 729 1235 1182 568 1014 969 170 154 1197