MULTIMEDIA SYSTEMS QCODE: 695 SUBCODE: 35281

PART-A Each question carries 2 marks. Answer five question. Q.no.8 compulsory.

1. What is virtual reality? Virtual reality is a system that gives the user the feeling of being in control of the environment or the environment interacting in response to the user’s action (a sense of real environment).

2. What is OpenGL? OpenGL (Open Graphics Library) is a cross-language and cross-platform API (Application Program Interface) used for defining 2D and 3D graphics images.

3. What is cell-based animation? Cell-based animations consists of multiple drawings, each one a little different from others. When displayed in rapid sequence the drawings appear to move.

4. What is the need for compression? (Any two) 1. To reduce the file size 2. To reduce the amount of required storage 3. To increase the speed of data access 4. To increase the speed of data transmission through network 5. To reduce the storage cost and transmission cost.

5. Expand PNG. PNG-Portable Network Graphics PNG format is used for high resolution graphics images and animation.

6. What is the function of DSP? Digital Signal Processor (DSP) controls the contrast and other details of the image and compress it. Then the image is stored as files such as JPG and GIF.

7. What is client side scripting? The scripting programs that run at the client machine is called client-side scripting.

8. What is MOD? Media on demand is a system that allows the user to select and watch the audio or video contents.

PART-B Each question carries 3 marks. Answer five questions. Q.no.16 compulsory.

9. What is 3D technology? How is holography related to 3D technology? If the pixel of an image is represented by three coordinate values X, Y, Z then it is a 3D image. Photographic recording of the light field of an image is known as hologram.

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Holography is a technique of creating 3D images by applying light effects, laser beam and optical illution on a photographic image.

10. Explain briefly about (a) Dithering Dithering is the process of changing the unavailable colors into the closest available colors. This is done by the help of color palette. (b) Rendering The process of converting 3-D objects into 2D objects on a computer display with the realistic effect is called rendering.

11. What is object based animation? Object based animations are created by moving an object across a screen. This type of animations is usually seen in computer games. For example, a car moving across the screen. In this animation only one picture is drawn. Then the entire picture is moved slowly.

12. List down the advantages and disadvantages of fractal compression. Advantages  Compression ratio is very high  Non-lossy compression.  Function are image resolution independent  When expanding the image, sharpness does not change. Disadvantages  It takes longer time for compression  Asymmetric compression.

13. Write briefly about social media sharing. Multimedia files are transferred and shared using storage devices such as CD, DVD and pen drives. It becomes easy to share multimedia files using social media networks such as Whatsapp, tweeter, facebook etc. Information can be shared through social media using computers as well as mobile phones.

14. Explain the working of active LED matrix display. An active LCD matrix display contains 640 x 480 pixels same as passive LCD matrix display. It is faster than passive LCD matrix system because the number of transistors used is very high. For example there are 640 x 480 x 3 = 921600 transistors used for VGA and 800 x 600 x 3 =1,440, 000 transistors used for SVGA display.

15. Discuss briefly about bandwidth bottleneck. Bandwidth is defined as the amount of data that can be transmitted in a given period of time. It is usually measured in bits per second (bps). Bottleneck is a situation occurring in a transmission medium when the bandwidth of incoming data is very lower than the receiving end. Bottleneck generally occurs due to poor transmission medium like telephone medium.

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16. Compare MIDI and digital audio. [Any Three]

S. No MIDI Digital Audio 1 Smaller file size 200 to 1000 times larger than MIDI. 2 Requires less CPU resources More CPU resources required 3 Can be load and play quickly on web Slower performance on web pages. pages 4 Quality depends on the synthesizer Quality depends on the file format 5 Does not support spoken dialogue Supports spoken dialogue 6 Less number of software tools available Very large number of software tools for editing MIDI. available for editing digital audio. 7 Musical knowledge must be required. User need not be having musical knowledge.

PART-C Each question carries 10 marks. Answer division (a) or division (b).

17. (a) (i) Explain the various multimedia elements. [Any five] [5m]

Multimedia applications require dynamic handling of data consisting of a mix of text, voice, audio components, video components and image animation. Based on the definition of multimedia, its elements fall into 10 categories. Fascimile: FAX was the first practical means of transmitting document images over telephone lines. This basic technology has lower dpi of 100 to 200. Document Images: Document images are used for storing business documents that must be retained for long periods of time or may need to be accessed by a large number of . Providing multimedia access to such documents removes the need for making several copies of the original for storage or distribution. Photographic images: Photographic images are used for a wide range of applications- such as employee records for instant identification at a security desk, real estate systems with photograph of houses in the database containing the description of houses and medical case histories. Geographic information systems map: Map created in GIS systems is being used widely for natural resources and wild life management as well as urban planning. The map containing database items contains wildlife statistics or details of the floors and rooms and workers in an office building. Voice commands and voice synthesis: Voice synthesis is used for presenting the results of an action to the user in a synthesized voice. Application such as a patient monitoring system in a surgical theatre will be prime beneficiaries of these capabilities. Voice commands allow the user to direct computer operation by spoken commands. Audio message: annotated voice already uses audio or voice messages as attachments to memos and documents such as maintenance manuals. Video messages: they are being used in a manner similar to annotated voice mail. Stored and live full-motion video: Stored full-motion videos are used for e-mails and live full-motion videos are used for presentations and video conferencing. Fractals: The objects that are stored as computer generated algorithms are known as fractals.

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(ii) Explain in detail about the structure of a VRML file. [5m] A VRML file contains the following The file header Comments - remarks to the user Nodes - Scene information Fields - Attributes of the node Values - Values of the attributes Node name - Names of the nodes. Example The following VRML code is written to create a 3D cylinder. #VRML V.20 ut f8 #A cylinder Shape { Appearance { Material matrial {} Geometry cylinder { Height 2.0 Radious 1.5 } } }

(Or) (b) (i) Explain in detail about hypermedia documents. [5m] Hypermedia documents are computer based documents that contains text, graphics, audio and video on pages that are connected by navigational links called hyperlinks. These links allow multiple views and non-linear interactions of information. Hypermedia documents can be printed, written, read, sent and received in electronic form through networks. Hypermedia documents are the electronic documents that contain not only text but linked multimedia objects such as image, audio and full-motion video.

The multimedia document with rich set of interlinks and hyperlinks is known as hypermedia document. Hypermedia document contains HYPERTEXT and HYPERSPEECH.

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Hypertext – Text that contains link with another document or another page of the same document is known as Hypertext. Hyperspeech – is a speech only hypermedia application that explores issues of speech user interfaces and navigations.

(ii) Write short notes on Windows and open source API. [5m] The open source helpers like mGitHub and SourceForge provide invaluable resources for those searching for assistance in creating their own applications. Most popular development tools, mobile development tools, , text editors and IDEs are available in open source. Some of the open source. Software are below. (a) Software Development – GW-BASIC, JSript, VBscript, visual studio, Visual Studio, Visual C#, Visual J#, Visual J++, Windows API. (b) 3D softwares – Microsoft Softimage, Direct 3D, Windows 3D Builder, Microsoft VRMI 2.0, Holo studio. (c) Operating Systems – MS-DOS, Windows NT, Windows CE, Windows Mobile, Windows XP, Windows 7, Xenix. (d) Windows Components – , Calculator, Paint, Notepad, Windows Chat, .

18. (a) (i) Explain about hypertext tools. [5m] Hyper text writers need to work with complex structures. Hypertext tools are used to displaying and manipulating these hypertext structures. Example: Storyspace, Eastgate web squirrel These tools are used to build the complex structures through direct manipulation. Instead of describing the structure., the winter just up pick up the objects on the screen, drag them into other objects or draw connection between the objects. The following figure shows creating structure using the hypertext tool story space

In the above figure, the user paced nine objects and drew the links among them.

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(ii) Write briefly about colour image processing. [5m] Color image is a digital image in which each pixel having colour information. A colour image has three values per pixel, they measure the intensity, chrominance and brightness of light. A colour image is usually stored in memory as a two dimensional array of small integer triplets. The number of bits used to indicate the colour of a single pixel is known as colour depth. Colour image processing includes the following: Colour balance: It is the adjustment of the intensities of the primary colors Red, Green, Blue. Colour mapping: It is a function that transforms the colors of one image to the colors of another image. Colour normalization: It is a function that is used to compensate the variations in colour values of each pixel. Colour constancy: It allows the user to assign a constant colour to the object even under different illumination conditions. Colour Quantization: This is a process that reduces the number of distinct colours in an image. Colour indexing: In this technique, colour information is not stored in the pixel data, but it is stored in a separate piece of data called palette. This is only for memory saving purpose. Colour moments: This technique is used for scaling and rotating the colour images using algorithms.

(b) (i) Explain the various audio formats supported by internet. [5m] The sound formats supported by internet are based on the web browser. There are various sound formats supported by internet. The WAVE Format: The WAVE format was developed by IBM and Microsoft. It is one of the more popular formats it is not only supported by computers running the windows , but also by all popular web browsers. Files in the wave format have the extension .WAV The MP3 Format: This format is developed by Motion Pictures group for storing music. They offer good compression and high quality. They are supported by most popular web browsers. The MP3 files have the extension .MP3. The windows media format: the windows media format was developed by Microsoft. It is one of the very popular formats on the internet and on computers with the windows operating systems. It should be noted that this format requires the installation of an additional components in non-windows computers. Files in the windows media format have the extension .WMV The MIDI format: The Musical Instrument Digital Interface is an internationally accepted file format used to store MIDI data. Most of the popular browsers support MIDI files. These files are stored with extension .MID. The shock wave format: The shock wave format was developed by Macromedia and is used to store multimedia components created using Flash. This format requires an extra component to play. The additional component comes preinstalled with the latest version of Netscape and Internet Explorer Files in the shockwave format have the extension .SWF.

(ii) Explain briefly about image enhancement. [5m] The process of improving the quality of a digitally stored image is known as image enhancement. For example to increase or decrease the contrast of the image, to make an image lighter or darker etc.

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Advanced image enhancement software tools are available, to provide better human view and better input images to multimedia projects. Image enhancement includes: Image stretching: It is also known as normalization that is used to change the range of pixel intensity values of an image. This technique is used to improve the contrast of a photograph with poor contrast. Image sharpening: Sharpening is a technique for increasing the apparent sharpness of an image. It is done by increasing the resolution and acutance. Image shrinking: Shrinking is the process of decreasing the contrast by making brighter pixels less bright and darker pixels less dark. Image sliding: Sliding is the process of changing the overall visible effects by brightening or darkening the image. Image Scaling: Scaling is the process of enlarging or shrinking the whole part of an image. Image rotation: Rotation is the process of rotating the whole image about a center point. Image Filtering: Filtering is the process of reducing the noise and highlighting the edge of an image.

19. (a) (i) Explain non-lossy compression schemes. [5m] Non-lossy compression is a standard that can retain all information in the original multimedia object. The CCITT (International consultative Committee for Telephone and Telegraph) group introduced many algorithms for non-lossy compression. CCITT Group2 It is very earlier compression scheme for low resolution images. It is not in use anymore. CCITT Group 3 – ID This compression scheme is used for black and white images. It is also known as run-length encoding.

CCITT Group 3 – 2D This compression scheme is used for document imaging systems. It is also known as modified run-length encoding. This compression gives a better compression ratio. CCITT Group 4 This compression is a 2D coding scheme for images with high resolution. This scheme also gives the best compression ratio. CCITT Group 5 This compression scheme is used for gray scale and 256 colour images.

(ii) Explain TWAIN architectures. [5m] The multimedia objects such as text, images, audio and video are created and captured using different types of input devices such as scanners, cameras and microphones. When data are created from different sources with the help of different software applications, the data had to be stored in a number of disk files. The stored data can be accessed by different applications at anytime through network. This is very complex and conjuctive. The architecture of TWAIN is shown in the following figure.

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Application Layer This layer makes the connection between the application and device. Protocol Layer It is the most important layer in the TWAIN architecture. This layer is responsible for communication between the application layer and the acquisition layer. Acquistion Layer This layer contains the virtual device driver to interacts directly with the device driver. This layer is also called source layer. Device Layer The purpose of device layer is to receive the software commands and control the device hardware accordingly.

(b) (i) Explain briefly about JPEG compression. [5m] JPEG is a compression standard for colour and gray scale images. It is a lossy compression. The major concept of this compression scheme is removing the data redundancy. The JPEG compression algorithm is done through three major steps.  Discrete cosine Transform (DCT)  Quantization  Entropy Encoder Discrete Cosine Transform DCT is a mathematical function that removes the data redundancy by transforming data from the spatial domain to a frequency domain. Quantization Quantization is the process of determining whether the information discarded by DCT without a significant loss of visual performance. Quantization is done by a Quantizer that uses many-to-one mapping fundamental. Entropy Encoder Entropy is defined as a measure of disorder, randomness and the measure of systems ability. The Entropy encoder compresses the quantized DCT coefficients.

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The following figure shows the JPEG compression methodology.

The JPEG compression is a symmetrical algorithm that means the decompression is the exact reverse process of compression.

(ii) Explain in detail about user generated media content sharing. [5m] User generated content (UGC) or User Created Content is any form of content created by the users of a system and made available publicly on that system. The content may be images, videos and audios and they can be shared to online platforms such as any social media web sites. UGC is used for a wide range of applications including news, advertising, entertainment and research. Social media sites like Face book, Twitter and Instagram allows the user to interact with other people chatting, messaging and image postings. Media hosting sites such as YouTube allow users to post media contents. The following figure shows that how much do sites profit from UGC in 2010.

Advantages of UGC  Better understanding of the customer  More site engagement  Increased customer satisfaction  Stronger community  Increasing SEO.

20. (a) (i) Explain the various types of video image processing. [5m] Image processing is a process of manipulating images such as brightening, sharpening and other several image operations. Types: 1. Pixel processing 2. Interframe image processing 3. Frame processing 4. Filter processing Pixel Processing  Histogram sliding: Histogram sliding is used to change the overall visible effect by brightening or darkening of the image.

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 Histogram stretching: Histogram stretching is used to increase the contrast by making the brighter pixels even more brighter and the darker pixels even more darker.  Histogram shrinking: Histogram shrinking is the process of decreasing the contrast by making the brighter pixels less bright and darker pixels less dark.  Pixel threshold: Pixel threshold is the process of set a limit on the bright and darkness of a picture. Interframe image processing  Image averaging: Image averaging is the process of minimizing the effect of random noise.  Image subtraction: Image subtraction is the process of determining the change from one frame to the next frame. Frame Processing  Image scaling: Image scaling is the process of enlarging or shrinking the whole part of an image.  Image rotation: Image rotation is the process of rotating the whole image about a center point.  Image translation: Image translation is the process of moving the image from up, down, left or right. Filter processing  Low pass filter: Low pass filter is used to blurring the image by reducing noice.  High pass filter: High pass filter is the process of emphasizing the edges of an image.  Laplacian Filter: Laplacian filter is the process of highlighting all edges of an image.

(ii) Write about instant multimedia. [5m] Size of a multimedia project is measured by the duration of development process and number of persons in the team. Mostly multimedia projects are developed in a couple of weeks or months by a team of 10 to 20 members. Some multimedia projects are developed in a couple of hours by a single person. This product is called Instant Multimedia. Instant multimedia projects need the following requirements. 1. Developer must have skill in all types of multimedia tools such as text editing tools, audio editing tools, movie editing tools and animation tools. 2. Computers must be able to run all types of multimedia software. 3. Computers must have all types of multimedia related devices. 4. Computers must have a large number of collections in already captured images, audio, videos and clipart.

(b) (i) Explain the architecture of a video capture board. [5m] A full-motion video capture board is a circuit card that is used to capture videos. It consists of the following architecture.  Video input  S-video input  Video compression decompression processor  Audio compression-decompression processor  ADC  DAC  Audio input

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The following figure shows the architecture of video capture board.

Video input-Video input system accepts video signals in RS170 standard. Video compression decompression processor- Video compression and decompression processor is used to compress and decompress the video data. Audio compression-decompression processor- Audio compression and decompression processor is used to compress and decompress the audio data. ADC- (Analog to digital converter) converts the input data into digital. DAC- (Digital to analog converter) converts the digital data into analog for output. Audio input- Audio input system accepts audio inputs from microphone, line-in and CD-in.

(ii) Explain how multimedia applications are produced for web. [5m] Multimedia applications can be developed for the web that means they can be accessed through internet. To create web based multimedia applications the following languages are used.  HTML (Hypertext Markup Language)  XML (Extensible Markup Language)  Java  Java script  AJAX (Asynchronous Java Script And XML)  CSS (Cascading Style Sheet)  ASP (Active Pages)

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21. (a) (i) Explain the various user interfaces. [5m] User interface can be done by the following.  Menus  Dialog boxes  Buttons  Icons Menus Menus are the most common elements in multimedia user interface. Menus are used for grouping the commands so that the user can easily access them. Each command in the menu is called menu items. When the user selects a menu item the corresponding operation is processed. Dialog Boxes Dialog boxes are small text boxes that provides place to the user for entering any information. Buttons Buttons are the small clickable text that is covered by a rectangle. When the user clicks a button the corresponding action will be performed. Icons Icons are the graphical symbolic representation of processes. When clicking an icon, the corresponding process is executed.

(ii) What are the various factors to be considered when adding video on web? [5m] When adding video on web, the developer must consider the following:  Video must be compressed for increasing the bandwidth.  Use high speed cable modems for internet connection.  Convert the video file format into MPEG format.  Avoid using more video files in an application.  Edit the video such as trimming, cutting before embedding the video in the application.

b. (i) Define plug-in. Explain its types. [5m] Plug-ins are helper applications that are used by browsers to view and interact with new types of documents and images. With the help of plug-ins, browsers can view any type of information. Types: There are several plug-ins  Text Plug-ins  Image Plug-ins  Sound Plug-ins Text Plug-ins Text plug-ins are used to download large text documents with special fonts. Example: Adobe Acrobat Reader Acrobat Reader is a plug-in that is used to deliver a text document from internet to the client in the PDF format. Image Plug-ins Image plug-ins are used to enable viewing the vector formats. They are used to decompress the images and display on client machine. Example: Adobe Photo-viewer

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Sound Plug-ins Sound plug-ins are used to receive and playback any kind of sound files from the web. Example: Windows Media Player, Real-time Player etc.

(ii) Explain briefly about E-learning and education. [5m] A learning system with the help of electronic resources instead of traditional class room is known as E-Learning. E- Learning can be termed as a network based transfer of skills and knowledge in which education is delivered to a large number of recipients at the same or different time. Advantages of E-learning:  Web based distance education  No face-to-face interaction  Flexible timing and place  Students can share their problems with teachers  Faster delivery of notes and syllabus  Lower cost  Lower environmental impact  Not necessary for physical presence to the class room.

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Prepared by

PUSHPA SHEELA E [41205212] Part Time / Guest Lecturer 120, Government Polytechnic College, Purasawalkam, Chennai – 12.

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