1. What is a computer graphics?

Ans. Computer graphics is a branch of computer science. It can be defined as use of computer to define store, manipulate, interrogate and present pictorial out of the data.

2. What is a pixel ?

Ans. Pixel is defined as the smallest size object or color spot that can be displayed and addressed on a monitor. Any image that is displayed on the monitor is made up of thousands of such small pixels.

3. What is a resolution ?

Ans. Image resolution refers as the pixel spacing i.e. the distance from one pixel to the next pixel. A typical PC monitor displays screen images with a resolution somewhere between 25 pixels per inch and 80 pixels per inch.

4. What is bitmap and pixmap?

Ans. On a black and while system with one bit per pixel, the frame buffer incalled bitmap

For systems with multiple bits per pixel, the frame buffer in referred to as a pix map.

5. What is the significance of initgraph () function?

Ans. Function Initgraph (int driver, int mode, char path);

This function is used to initialize the graphics system to load the appropriate specified graphics driver and video mode used by the graphics function. The path is to specify the place in which the graphics driver files are available.

6. JPEG uses ________ compression technique.

Ans. Lossy

7. Why we use scanner ? Name the different types of scanner.

Ans. Photographs, illustrations, and paintings continue to be made the old fashioned way, even by visual artists who are otherwise immersed in digital imaging technology. Traditional photographs, illustrations, and paintings are easily imported into computers through the use of a device called a scanner.

Types of scanners: Flatbed or Sheet-fed Scanner Handheld Scanner Film Scanner 3-D Scanners

8. What is sampling ?

Ans.Wave files contain digitally recorded sounds. This process is often referred to as Sampling. Sampling is like breaking a sound into tiny piece and storing each piece as a small, digital sample of sound. The rate at which a sound is Sampled can affect its quality. The higher the sampling rate (the more pieces of sound that are stored) the better the quality of sound. Higher quality of sound will occupy a lot of space in hard disk because of the more samples.

9. How many colors are there in RGB color mode?

Ans. RGB images use three colors, Red, Green, and Blue. These colors are known as primary colors.

10. Briefly explain the concept of 2D and 3D.

Ans. Multimedia application starts off with a series of images in sequence. This can be simply achieved by drawing a series of images and trying to make them look like a sequence. 2D component of multimedia involves drawing images, which has only 2 dimensions and animating them. The best examples would be that of cartoons such as Tom and Jerry, The Lion King and many more.

Artists were to draw every frame by frame-on paper and make them flip through so as to get an illusion of animation. It becomes much tedious with the color because every frame has to have the same colors. With the advent of multimedia the process becomes much simpler because artists could draw their drawings on the screen and animate them frame by frame the basic need of drawing every frame still remains, but the software has enabled us to speed up the process and coloring becomes much simpler. The cost also reduces considerably.

The most interesting and modern technology that Multimedia has offered is the third dimension. Using the 3D areas, we will be able to model, animate and texture different objects which exist in reality or make them unseen reality like the dinosaurs of Jurassic Park, the tornados of Twister, the blaster and spacecraftsof Independence Day and many more.

The 3D world offers facilities such that you will be able to model whatever you visualize and conceive which can exist or may not exist. We will be able to animate those objects accordingly.

11. Briefly narrate the history of graphics hardware technology.

Ans. In early days, the high cost of the hardware for computer graphics remained the obstacle, which prevented their widespread use. Computers have been getting progressively more inexpensive and it has become a household article these days. The microelectronics revolution and the subsequent reduction in the price of the digital hardware have completely changed the situation. Due to this price reduction, it is now realistic to expect that all computers with graphic display hardware capability will be making extensive use of computer graphics.The announcement of the IBM personal computer using 16-bit Intel 8088 microprocessor on August 12, 1981, can be regarded as a historic event, which had a profound effect in the world of computers. These computers significantly improved the state of display technology in the world of computers.The next major change in PC display technology was announced by Apple Company in 1984, when it introduced the Macintosh PC. It was the first PC that did not include a text-based display but provided only a graphic display. The application programs developed for the Macintosh advocated WYSIWYG (What You See Is What You Get) style of interface. This concept has become a basic requirement in the area of desktop publishing (DTP). The PowerPC's from IBM, Apple, and other vendors created a new standard for DTP computers. With such a development, computer graphics and multimedia has become a necessity for all types of users.

12. Discuss the different applications of computer graphics.

Ans. There are many different application of computer graphics.

1.Building Design and Construction:- Computer graphics are very useful tool for generating architects drawings and visualizing structures. The architect can Walk through building, looking at images on the computer

2. Electronics Design:-In this time electric equipments like radio, television and computers are made up of many small electric devices and components. These parts are mounted on PCBs (printed circuit board) and interconnected by copper tracks on boards. Until few years ago the design of PCBs was done entirely by hand. Today this procedure is completely computerized.

3. Mechanical Design:-We know machines are simply complex arrangement of mechanical parts. Today, constructive solid geometry technique (CSG) is used to design different parts on computer.

4. Entertainment and Animation:-Computers are used in making cartoon animation films. It requires tedious calculation for which computers are ideally suited.

5. Aerospace Industry:-Aircraft designer use computers to simulate the airflow over the wings. The air patterns around the wings are displayed on the graphics monitor. The patterns of the shock waves around the aircraft give the designer an idea about the area that may create unwanted turbulence. It is possible by using super computer such as CRAY or ETA.

6. Medical Technology:-Today, Computerized axial Tomography (CAT) are used to compose the three dimensional model of the brain by taking multiple X-rays of it. CAT scan is very useful in detecting various problems like brain tumors etc.

7. Cartography:-Computer graphics is used to produce accurate and schematic representation of geographical and other natural phenomena from measurement data.

8. Art and Commerce:-Computer graphics is used to produce pictures that express a message and attract attention. Personal computers and teletext and videotext terminals in public places such as museums, transportation terminals, supermarkets and hotels, as well as in private homes, offer much simpler but still informative pictures that let users orient themselves, make choices, or even teleshop and conduct other business transactions.

13. Explain the working principle of CRT.

Ans.The mostly video monitor is based CRT design. Cathod ray tube is based on the simple concept that an electronic beam, when hit a phosphorescent surface, produces a beam of light. Beam of light itself can be focused to any point on the screen by using suitable electronic/magnetic fields. The direction and intensity of the fields will allow one to determine the extent of the deflection of the beam. Further these electronic/magnetic fields can be easily manipulated by using suitable electric fields with this background. The electron gun produces a stream of electrons. The beam itself can be switched on/off easily by switching on/off the heating system. The beam itself is focused towards the phosphor-coated screen. The point where the beam hits the screen becomes phosphorescent and produces a speck of light.

14. List out the differences between vector scan display and raster scan display.

Ans.

15. Explain different input devices for data input on graphics workstations.

Ans.

Various devices are available for data input on graphics workstations. These include mouse, trackball, joystick, digitizers or graphics tablet, light pen, 3-D devices etc.

Mouse: A mouse is a small handled box used to position the screen cursor. It has two wheels at right angles to each other. Each of these wheels is connected to the shaft encode. For every incremental rotation of the wheel, an electrical signal is produced by the shaft encode. As the device is moved on a flat surface, the movement is coded in the x and y directions by counting the number of pulses received from the shaft encoder. These values are held in separate registers and the computer can sample them at a suitable rate. The device can, therefore, be used for moving a cursor around the display screen.

Track Ball: Two orthogonal wheels controlling the potentiometers are driven by the tracker ball. If the ball is moved at right angles to the direction of one of the wheels then that wheel is not affected. The tracker ball is useful when the cursor on the screen is to be moved by a small amount. This device is quite slow for large movements of the cursor.

Joy Stick: The prototype of the mouse is a joystick. The name suggests, we have a stick that can be moved in all possible directions and amount of movement in that direction controls the curser movement. Once the curser arrives at the desired position, clicking the buttons can choose the picture and any modification can be made. In fact, the joysticks were originally used for video games, but later on modified for the more accurate graphics requirements. However, both the mouse and joysticks may appear a bit cumbersome for the new users. They find some difficulty in aligning the curser to the precisely desired positions.

Digitizer: A Common device for drawing, painting or interactively selecting co-ordinate positions on an object is a digitizer. These devices can be used to input co-ordinate values in either 2-D or in 3-D space. One type of digitizer is the graphics tablet, which is used to input two dimensional co-ordinates by activating a hand cursor or stylus at selected positions on a flat surface.

16. Formulate 'C' program to draw structure of fish and give animation.

Ans.

#include#include#include#include#includevoid main() {int gdriver=DETECT,gmode;int i;initgraph(&gdriver,&gmode,"e:\\tc\\bgi");int max_y=getmaxy()/2;i=0;setcolor(BLUE);while(!kbhit()) {line(0+i,max_y+30,0+i,max_y-30); /*triangle*/line(0+i,max_y+30,30+i,max_y);line(0+i,max_y-30,30+i,max_y);ellipse(90+i,max_y,0,360,60,35);circle(120+i,max_y-5,5);i=i+3;if(i>=635)i=0;delay(100);cleardevice();}getch();closegraph();}

Inform the students that the path e:\\tc\\bgi should be changed according to the machine settings. The code given here has been tested on Turbo C 3.0.

17. Compare the features of text and graphics mode.

Ans.

The following table compares the text and graphics modes: Text mode Graphics mode

You can only handle text.You can display, capture, and animate figures.

You can display in 16 colors on a color monitor.You can display various colors.

Text mode display is in two forms, 25 rows of 40 columns or 25 rows of 80 columns.The resolution of the graphics mode depends on the adapter.

18. List the different graphics functions along with example.

Ans.

Graphics functions of c Languages are:--

a. initgraph (int driver, int mode, char path); -This function is used to initialize the graphics system to load the appropriate specified graphics driver and video mode used by the graphics function.

b.restorecrtmode();- This function restores the screen to the mode that it had prior to the call to initgraph().

c.setpalatte(int index, int color);-This function chooses an index for palette and matches the color with the index and this color sets the background of CGA mode.

d.putpixel(int x, y, int color);- This function illuminates the pixel represented by x and y coordinates in the color represented by color.

e.getpixel(int x, int y);-This function returns the color in which the pixel(x,y) is illuminated.

f.moveto(int x,y);- This function position the cursor into the pixel(x,y)

g.lineto(int x, int y);-This function draws a line from the current cursor position to (x,y).

h.line(int x1, int y1,int x2, int y2);- This function draws a line from (x1,y1) to (x2,y2)

i.bar(int x1, int y1, int x2 , int y2);- This draws a rectangle with diagonal from(x1,y1) to (x2,y2).

J.bar3d(int x1, int y1,int x2, int y2,depth,topflag);- This function provides a 3 dimensional view of rectangle boxes. This draws a rectangle with diagonal from(x1,y1) to x2,y2) and with depth specified in ht variable depth. If the top flag is non zero , a top is added to the bar, and hence-3-Dimensional view is possible otherwise the bar has no top.

K.circle(int x, int y,radius);- This function draws a circle centered at (x,y) with the radius specified by the variable radius (in terms of number of pixels ) in the current drawing color.

L.arc(int x, int y, int start, int end, int radius);- This function draws an arc of the circle with radius as specified in the variable radius and with center at (x,y). start and end given in degrees to mention the portion of he circle that form the arc. Example:-- arc(100,100,0,90,20);

m.pieslice(int x, int y, int start, int end, int radius);- This function works in the same way as are but it provides the 2 radii from center to start and end Example: pieslice(100,100,90,180,50);

n.ellipse(int x, int y, int start, int end, int xrad, int yard);- This function draws an ellipse with xrad as radius along x axis and yard as radius along y axis. The start and end should be 0 and 360 for full ellipse. Arc of ellipse can also be drawn by changing the start and end values as used in the function arc(). Example:--ellipse(100,50,0,360,30,15):

19. What is multimedia? Give different applications of multimedia.

Ans.

Simply multimedia means using more than one kind of medium. It includes text, spoken audio,music, image, animation and video. The concept of multimedia was first applied in advertisement clips, animation and special effects in movies. Multimedia system was very popular till the arrival of desktop computers. With the introduction of soundboards built around tone-synthesis chips. The digital video overlay and capture boards can be easily installed and made it possible to display full motion video freeze a frame. Both audio and video interfaces, the focus of multimedia system design shifted to the processing of full motion video and audio data on desktop computer. The demand for multi-standard compression on the same system increases, several manufacturers introduced a new generation of compression chips that support software programming. High-speed networking has introduced opportunities for new multimedia application like video conferencing, medical imaging and scientific visualizations.

the different applications of multimedia.

Multimedia is user friendly and interactive mode of operation. Multimedia finds application in the field of entertainment. It is used in marketing broadcasting . It is also used in advertising, publishing telecommunications. It is used in training collaborative engineering and design manufacturing process. For example multimedia is being used in the supervision of highly automated industrial plants, power stations manufacturing units, etc. by way of integrating online electronic documentation facility with the process control system and other video controlled operations. This helps in ensuring safe and economic operation and ease in failure detection.

20. What is animation? Explain different types of animation techniques.

Ans.

Any webpage graphic element, which has movement such as blinking and text motion or curled video, is usually called animation. Two types of animation techniques: a) Object animation b) Frame animation or Cell animation.

Object AnimationObject animation is the moment of unchanged text and object around the screen. This type of animation is relatively easy to develop. For example, a multimedia presentation is a software programme to create a quick multimedia presentation. Creating an object animation usually involves specifying a path for the animated object to flow.

Frame animation or Cell AnimationFrame animation is made up of different frames or screens; they are rapidly displayed to simulate motions. Frame or cell animation makes it possible to appear to bend together, creating the effect of motion. 2D and 3D animation are fun, and add interest to a multimedia programme. The 3D animation adds the dimension of depth and reality. Another form of animation is MORPHING (Metamorphosing). Morphing involves a transition between two objects over a given number of frames. (i.e.) The first object appears to turn into the second object. Animation is truly fun component in Multimedia.

21. What is file format? Explain different image file formats.

Ans.The method by which the software organizes the data in the saved file is called the file format. The file name extension or suffixes indicate the format or usage of a file and a brief description of that format. Several different types of file format are used by various kind of software to save files. For example, the GIF file format used for Web page images is standard formats that can be opened by any program that supports it.

The various image file format are as follows:

Tagged-Image File Format (TIFF)

The Tagged-Image File Format (TIFF) is used to exchange files between applications and computer platforms. The TIFF format supports LZW compression, a lossless compression method that does not discard detail from the image.

When you save an Adobe Photoshop image in TIFF format, you can choose to save in a format that can be read either by Macintosh or by IBM PC compatible computers. You can also choose to compress the file to smaller size automatically by clicking the LZW Compression check box.Adobe Photoshop reads and saves captions in TIFF files. This feature is of particular use with theAssociated Press Picture Desk system, which uses the same TIFF caption fields.

Graphics Interchange Format (GIF)The Graphics Interchange format. A common graphics format of storing raster graphics. This formatis made popular by the computer serve and is supported by a number of hardware platforms.

Joint Photographic Experts Group (JPEG)The Joint Photographic Experts Group (JPEG) format is commonly used to display photographs and other continuous-tone images in hypertext markup language (HTML) documents over the World Wide Web and other online services. Unlike the GIF format, JPEG retains all the color information in an RGB image. JPEG also uses a compression scheme that effectively reduces file size by identifying and discarding extra data not essential to the display of the image. Opening a JPEG image automatically decompresses it. Encapsulated PostScript (EPS)The Encapsulated PostScript (EPS) language file format is supported by most illustration and page layout programs, and in most cases is the preferred format for these applications. Note that Photoshop EPS also supports transparent whites in Bitmap mode. Portable Document Format (PDF)Adobe Acrobat, Adobes electronic publishing software, uses the PDF format for Macintosh, Windows, UN1X, and DOS. Based on the PostScript Level 2 language, PDF can represent both vector and bitmap graphics. For the purpose of representing pages, PDF pages are identical to PostScript pages, but PDF files can also contain electronic document search and navigation features. PDF files, for example, can contain hypertext links and an electronic table of contents. Portable Network Graphics (PNG)The PNG format was developed as an alternative to the GIF format and, like GIF, is used for displaying images on the World Wide Web and other online services. PNG preserves all color information and alpha channels in an image and uses a loss less compression scheme to reduce file size.

TGA- TargaThe TGA (Targa) format is designed for use on systems that use the True vision video board and is commonly supported by MS-DOS color applications. If you are saving an RGB image in this format, you can choose the color depth you want.

22. Explain painting tool in photoshop.

Ans.

Painting tools contains the paintbrush tool, pencil tool, and airbrush tool to paint the current foreground color on an image. The three tools create different effects:

The paintbrush tool creates soft strokes of color. The pencil tool creates hard-edged freehand lines. The airbrush tool applies gradual tones (including sprays of color) to an image, Simulating traditional airbrush techniques. Theedges of the stroke are more diffused than those created with the paintbrush tool.

The use the paintbrush tool, pencil tool, or airbrush tool:-1. Specify a foreground color.2. Select the paintbrush tool, pencil tool, or airbrush tool. 3. Do the following in the options bar: Choose a preset brush. Specify a blending mode. For the paintbrush tool and pencil tool, specify opacity. For the airbrush tool, specify a paint flow. For the pencil tool, select Auto Erase to paint the background color over areas containing the foreground color. Do one or more of the following: Drag in the image to paint. To draw a straight line, click a starting point in the image. Then hold down Shift, and click an ending point. When using the brush tool as an airbrush, hold down the mouse button without dragging to build up color.

23. Describe the features of OpenGL.

Ans.

OpenGL itself isnt a programming language, or a software library. Its the specification of an Application Programming Interface (API) for computer graphics programming. In other words, OpenGL defines a set of functions for doing computer graphics. OpenGL is a Software Interface to Graphics Hardware OpenGL Consists of about 150 Distinct Commands

Main Features Of Opel GL Are:-- It provides 3D geometric objects, such as lines, polygons, triangle meshes, spheres, cubes, quadric surfaces, NURBS curves and surfaces;

It provides 3D modelling transformations, and viewing functions to create views of 3D scenes using the idea of a virtual camera;

It supports high-quality rendering of scenes, including hidden-surface removal, multiple light sources, material types, transparency, textures, blending, fog;

It provides display lists for creating graphics caches and hierarchical models. It also supports the interactive picking of objects;

It supports the manipulation of images as pixels, enabling frame-buffer effects such as antialiasing, motion blur, depth of field and soft shadows.

24. Explain the function format of OpenGL.

Ans.

25. Write a short note on:

i) Liquid crystal displays

It is well known as LCD. It is used in small calculators and laptop computes. These are non-emissive devices. It produce a picture by passing polarized light from the surroundings or from an internal light source through a liquid crystal material that can be aligned to either block or transmit the light. Thesecompounds have a crystalline arrangement of molecules. Liquid Crystal Display is shown in figure 2.6.

There are two methods for constructing LCD, a passive-matrix LCD and active-matrix LCD.LCD consists of a layer of liquid crystal, sandwiched between two polarizing plates. The polarizers are aligned perpendicular to each other, so that the light of the first polarizer will be blocked by the second. Because a polarizer plate only passes photons with their electric fields aligned parallel to the polarizing direction of that plate.

Fig. 2.6 Liquid Crystal Display (LCD)

Advantages Limitations Thin/low weight Image size < 13 inches (passive) Rugged and reliable < 16 inches (active matrix) Low voltage drivers Response time (passive) Premium cost (active matrix) Limited viewing angle Limited temperature range

ii) Wave files

Wave files contain digitally recorded sounds. This process is often referred to as Sampling. Sampling is like breaking a sound into tiny piece and storing each piece as a small, digital sample of sound. The rate at which a sound is Sampled can affect its quality. The higher the sampling rate (the more pieces of sound that are stored) the better the quality of sound. Higher quality of sound will occupy a lot of space in hard disk because of the more samples.

By connecting the Mic port to a Two-in-ones headphone port, we can record the Voice, Music or Speech to the hard disk with the help of wave file generating softwares. Two wave files can be mixed using the command like Past Mixed Past. The necessary components for recording a sound and mixing are Head phone, Stereo jack, Stereo Converter and stereo sockets

iii) GLU and GLUT libraries in OpenGL

Ans.

two utility libraries have been developed which greatly extend the low-level (but very efficient) functionality of OpenGL. The first is the OpenGL Utility Library, or GLU. The second is the OpenGL Utility Toolkit, or GLUT:

& GLU provides functions for drawing more complex primitives than those of OpenGL, such as curves and surfaces, and also functions to help specify 3D views of scenes. All GLU function names start with glu.

& GLUT provides the facilities for interaction that OpenGL lacks. It provides functions for managing windows on the display screen, and handling input events from the mouse and keyboard. It provides some rudimentary tools for creating Graphical User Interfaces (GUIs). It also includes functions for conveniently drawing 3D objects like the platonic solids, and a teapot. All GLUT function names start with glut.

26. Computer graphics can be classified into _____ and _____.

Ans. Bitmap And Images

27. A photoshop file can contain both vector and raster data (True/False).

Ans. True

28. ______________ along the height and width of bitmap image.

Ans. Resolution

29. Explain the working principle of the shadow-mask CRT.

Ans.The shadow mask CRT, instead of using one electron gun, uses 3 different guns

placed one by the side of the other to form a triangle or a Delta. Each pixel point on the screen is also made up of 3 types of phosphors to produce red, blue and green colors. The phosphor screen is a metal screen, called a shadow mask. This plate has holes placed strategically, so that when the beams from the three electron guns are focused on a particular pixel, they get focused on particular color producing pixel only. When focused on to a different pixel, the red beam again focuses on to the red phosphor and so on. Three beams are to be focused; the role of the Shadow mask becomes critical. If the focusing is not achieved properly, the results tend to be poor. Instead of one pixel point in a monochrome CRT now each pixel is made up of 3 points the resolution of the CRT for a given screen size reduces

beams, when hits a phosphorescent surface, produces a beam of light. Further, the beam of light itself can be focused to any point on the screen.

30. Discuss different input techniques for graphical interaction.

Ans. There are many name of graphical input interactive technique.

1 Positioning:-This operation is used for locating or introducing a symbol at a desired location on the display, for defining end points of a straight line, and/or for generating polygons, circular arcs or other geometric figures.

2. Constraints:-A constraint is a rule for altering input co-ordinate values to produce a specified orientation or alignment of the displayed co-ordinates. A horizontal or vertical constraint is implemented by determining whether any two input co-ordinate end points are more nearly horizontal or vertical.

3. Grids:-This is use to rectangular lines displayed in some part of the screen area, it is also kind of constraint. Spacing between grid lines is often an option that can be set by user.

4. Gravity Field:-Connecting between position and endpoints for constriction of figure. This conversion of in put position is accomplish by creating a gravity field area around the line.

5. Rubber band methods:-Rubber band method use to straight lines can be constructed and positioned. Which stretch out a line from a starting position as the screen cursor is moved, we first select a screen position for one endpoint of line.

6. Dragging:-A technique that is often used in interactive picture construction is to move objects into position by dragging them with the screen cursor. At a first we select the item the move to the cursor in direction, we want to object move .

7. Dimensioning Techniques:-It is often desirable to display the coordinate position or the dimensions along with the object. This would be helpful in ascertaining the location of the object, when mere visible accuracy of location may not be enough.

8. Selection of Objects:-One of the important points to be addressed is to select parts of the picture for further operations. Once the selection is made properly, tasks like moving, deletion, copying can be done.

31. Design a 'C' program to draw an Indian flag.

Ans. #include"graphics.h"#include"conio.h"void main(){int gd=DETECT,gm,x,y;initgraph(&gd,&gm,"c:\\tc\\bgi");x=getmaxx();y=getmaxy();clearviewport();setfillstyle(LINE_FILL,BLUE);bar(0,0,639,479);setcolor(6);rectangle(50,50,300,200);setfillstyle(SOLID_FILL,6);bar(50,50,300,100);setfillstyle(SOLID_FILL,WHITE);bar(50,100,300,150);setfillstyle(SOLID_FILL,GREEN);bar(50,150,300,200);setcolor(BLUE);rectangle(45,45,50,300);setfillpattern(0x20,MAGENTA);bar(45,45,50,400);setcolor(BLUE);circle(175,125,25);line(175,125,200,125);line(175,125,175,150);line(175,125,150,125);line(175,125,175,100);line(175,125,159,107);line(175,125,193,143);line(175,125,159,143);line(175,125,193,107);setcolor(YELLOW);rectangle(0,0,640,43);setfillstyle(SOLID_FILL,YELLOW);bar(0,0,640,43);setcolor(BLACK);settextstyle(1,HORIZ_DIR,5);outtextxy(150,0,"INDIAN FLAG");getch();}

32. With illustration narrate the origin and development of multimedia technology.

Ans.Multimedia is an effective medium to express information in a more attractive way. It makes use of text, pictures, audio, animation, and video. It was started more then 25 years ago. However, it only became popular with the advent of desktop computers. Audio was the first multimedia data incorporated into desktop computing, with the introduction of soundboards built around the tone-synthesis chips. In addition, video could also be captured, displayed and stored on a computer disk with the help of digital overlay and capture boards installed on any ordinary computer.

However, the use of audio and video on desktop computers was limited due to their large size and high computing power requirements. These limitations were overcome through the introduction of compression/decompression engines for reducing the sizes of these files. As the demand increased for multi standard compression on the same system, several manufacturers introduced a new generation of compression chips that supported software programming. These chips contained hardware engines for operations requiring high computing power and also integrated processors that can be programmed to control data flow within the chip. Such technologies made audio and video boards capable of transferring data to computer systems efficiently, in some cases, in real time.

The advent of RISC technology, parallel processing architecture, high speed hard disk, optical disk drives and a variety of interfacing devices made it possible to design computer systems that have multimedia features as standards.

The latest breakthrough in the field of multimedia was the advent of the Internet and other high-speed networking technologies. These have presented new opportunities such as video conferencing, medical imaging, and scientific visualization.

33. Give the steps to use the image printing utility of photoshop.

Ans.

In Photoshop, you can print a complete image, selected area of an image, or even one or more layers. To print a complete image, select File --> Print from the main menu (or press Ctrl + P). The Print dialog box opens up as shown in the following figure:Ensure that the All radio button is selected. You can also set the print resolution by selecting it from the Print Quality drop-down. After making the desired print settings click OK to print.To print a selected area, make a selection in the image using the Rectangular Marquee tool and select File >Print. Select the Selection option button in the Print dialog box and click OK.Note that by default, Photoshop prints all visible layers and channels. If you want to print just certain layers or channels, make them the only ones that are visible and then print.You can also choose to print the filename, along with crop marks, registration marks and a caption along with the image. To set such options, select File >Page Setup in Photoshop 6. The Page Setup dialog box opens as shown in the following figure:You can select the checkboxes if you want to include the corresponding options in the printed image: Caption: Selecting this checkbox will print a caption with the image. This caption can be set in the File Info dialog box. To open the File Info dialog box select File > File Info, and choose Caption from the Section drop-down list. Type a caption in the Caption text area and click OK. Calibration Bars: Select this checkbox to print the calibration and color bars for your image. A calibration bar is a row of 11 gray squares of different values. A color bar is a row of 11 colors. These bars can be helpful when trying to calibrate to a specific printer. This option is available only for a PostScript printer. Registration Marks: Select this checkbox to print a registration mark such as bull's eyes around the image. These marks can be helpful for aligning color separations. Corner Crop Marks: Select this checkbox to view horizontal and vertical lines around the corners of the image, defining where the image should be trimmed. Center Crop Marks: Select this checkbox to view the exact center of the image defined by two crossed lines. Labels: Select this checkbox to print the file name next to the image. You can also print the name of the appropriate color channel if you are using color separations.Negative: Select this checkbox to print an image that appears like a negative of the original image. With this option selected, the colors are reversed. Emulsion Down: Select this checkbox to print the image as a horizontal mirror image of the original image. Interpolation: Interpolation refers to a printer's ability to resample an image as they print it to improve its resolution. This option is useful in case of low-resolution images. The buttons on the left side also present some useful options such as printing a border around the image and printing a background with the image.

34. Write a short note on :

i) Display devicesThe most prominent part in a personal computer is the display system that is responsible for graphicsdisplay. The display system may be attached with the PC to display character, picture and video output.

Some of the common types of display system available in the market are, Raster san displays Random scan displays Direct View Storage Tube Flat panel displays LCD etc.

The display systems are often referred to as video Monitor or video display unit. The most common video monitor that normally comes with a PC is the Raster scan type.

However, every display system has mainly three basic parts- the display adapter that creates and holds the image information, the monitor, which displays that information, and the cable that carries the image data between the display adapter and the monitor.

ii) TabletsMouse cannot be used to trace handwritten characters / pictures. Suppose we are able to trace these drawings and if the software could produce the same on the screen, it would be convenient at least in some cases. This is true not only in terms of drawings, but also handwritten characters or letters. But the mouse, with its fairly limited resolution, cannot be made to trace such pictures accurately. Tablets are developed to do this job. They can also be used to draw pictureson a paper, which can be transferred to the screen. Several techniques for developing such tablets are available. A simple method is by using a flat area,which rests as a tabletop. Several horizontal and vertical lines into grids divide the rectangular area. A stylus or a pen like apparatus, which is connected by a coaxial cable to the computer, is used to point to the grid. Each horizontal and vertical line carries a uniquely coded digital signal. When the stylus touches the junction of one horizontal and another vertical junction, the stylus picks up their corresponding signals. For example the 100th vertical signal and 125th horizontal signal identifies the position as the junction of the 100th vertical and 125th horizontal line or say the point (125, 100) that is unique. Thus, later if the stylus is later moved to the positions (124, 101), (123,102) etc, the system can very easily keep track of these movements.

The digital signal concept is not the only method of identifying the position. An acoustic tablet can make use of sound signals to identify the location

iii) Rubber band methods.Straight lines can be constructed and positioned using rubber-band methods, which stretch out a line from a starting position as the screen cursor is moved. We first select a screen position for one endpoint of line. Then, as the cursor moves around, the line is displayed from the start position to the current position of the cursor. When we finally select a second screen position, the other line endpoint is set. Rubber-band methods are used to construct and position other objects besides straight lines. Below figure demonstrates rubber-band technique

35. What is Photoshop ? What is gamut in photoshop ?

Ans. : Photoshop provides efficient, professional working environment that is the standard by which other products are judged. It has wide variety of toolsets for image editing.

Gamut is the range of colors that are displayed in RGB or HSB (red, green, blue and hue, saturation and brightness) on your screen. There are also LAB colors which have the largest gamut or range of color. And those colors that can be printed into CMYK, cyan, magenta, yellow and key (black). But may need some adjustments. Some colors that are out of gamut in Photoshop are brought back into gamut to the closet color so that your printer can easily recognize before printing. Photoshop will do this for you if you convert your image from RGB or HSB to a CMYK file.

Also the human eye can see more of the color spectrum than what is represented in Photoshop and what you see on the screen is not necessarily what you will see on print

36. Name the computer languages that supports computer graphics why C language is popular for graphics programming ?

Ans. Some languages that support computer graphics are:a. FORTRANb. BASICc. PASCALd. C

C has become a choice for today's professionals, developers for graphics programming. C is a structured language and is rich in expressive power and applicable to a wide variety of users. Because of the rich set of graphical functions available, this language helps in designing for graphical applications. The C code is small, fast, portable, and flexible.

37. Explain the principle of DVST system.

Ans. The Direct View Storage Tube (DVST) behaves like a CRT with highly persistent phosphor. Pictures drawn on this screen will be seen for several minutes (40-50 minutes) before fading. It is similar to a CRT as far as the electronic gun and phosphor-coated mechanisms are concerned. However, instead of the electron beam directly writing the pictures on the phosphor coated CRT screen, the writing is done with the help of a fine-mesh wire grid. The grid made of very thin, high quality wire is located with a dielectric and is mounted just before the screen on the path of the electron beam from the gun. A pattern of positive charges is deposited on the grid and this pattern is transferred to the phosphor coated CRT by a continuous flood of electrons. This flood of electrons is mounted by a "flood gun", which is separate from the electron gun that produces the main electron beam.

38. What is aspect ration ? Why it is to be maintained while designing a monitior ?

Ans. The aspect ratio of the image is the ratio of the number of X pixels to the number of Y pixels. The standard aspect ratio PCs is 4:3, and some use 5:4. Monitors are calibrated to this standard so that when you draw a circle it appears to be a circle and not an ellipse.

39. Write a C program to draw human face using built in functions.

Ans.

#include#include#includevoid main(){int gdriver=DETECT,gmode=0;int i;initgraph(&gdriver, &gmode,c:\\tc\\bgi);cleardevice();rectangle(0,0,639,479);outtextxy(280,20,HUMAN FACE);arc(320,190,180,120);line(200.190,440,190);arc(320,230,160,380,120);arc(440,230,270,450,20);arc(200,230,90,270,20);circle(260,220,10);circle(380,220,10);for(i=0;i