Unit-9 :Geographical Information System-GIS (Notes of TU BSc. 4th Year Computer Science)

Geographical Information System (GIS)

Syllabus : Definition of GIS and Remote Sensing; Components of GIS; Map Projections: Spatial and Non- spatial Data; Data Model and Input, Data Analysis and Output; Remote Sensing Applications: Agriculture, Forestry, Land Use / Land Cover Mapping, Water Resources, Snow and Glacier, Wetland Management 

GIS

A GIS is a computer based tool for mapping and analyzing feature events on earth and space. GIS integrates common database operations such as query and statistical analysis with maps.

Simply, we can say that GIS is an integrated set of hardware and software tools used for the manipulation and management of geographical data and related attribute data. GIS performs map making and geographic analysis faster and with more sophistication than traditional manual   methods. Some advantages of GIS are:

1. Improved decision making - Decisions are made easier because specific and detailed information is presented about one or more locations.
2. Reduced costs and increased efficiency : Route of delivery can be optimized with the help of GIS which saves time.
3. Improved communication : Communication in the visual format is easily understood by all.
4. Easy record keeping : Geographical changes are easily recorded by GIS for those responsible for recording the change.
5. Managing geographically : Knowing what is and when will occur in geographic space in order to plan a course of action.

Remote Sensing

Art and science of making measurement of the earth using sensors on airplane or satellites is called remote sensing. Sensors collect data in the form of images and provide specialized capabilities for manipulating, analyzing and visualizing those images. Remote sensed imageries integrated within a GIS. RADAR and LiDAR are examples of active remote sensing. Film photography, infrared, charge couple devices, etc. are examples of passive remote sensing.

Passive sensors gather radiation that is emitted or reflected by the object or surrounding.

Active sensors emits energy in order to scan objects and areas whereupon a sensor that detects and measures the radiation that is reflected or backscattered from the target.

Who uses Remote Sensing and why?

1. Geographer - to look changes on earth’s surface that need to be mapped.
2. Forester - for information about what types of trees are growing.
3. Environmentalist - who wants to detect, identify and follow movement of pollutants such as oil sticks on oceans.
4. Geologist - who is interested in finding valuable minerals. 
5. Farmers - for keeping eye on how crops are growing.
6. Ship captain - for finding routes.

Components of GIS

The different components of GIS are:

1. Hardware
2. Data
3. People
4. Methods
5. Software

a) Hardware

It is the computer on which a GIS operates. Software runs an a wide range of hardware types, from centralized computer servers to desktop computers used in stand alone or networked configurations. 

b) Data

It is most important and often most expensive component of GIS. Geographic data which is comprised of geographical features and their corresponding attribute information is entered into a GIS using a technique called digitizing. Process involves digitally encoding geographic features such as buildings, roads or country boundaries.

c) People

Real power of GIS comes from the people who use them. GIS is being used by people in many different fields as a tool that enables them to perform their jobs more effectively. Police use GIS to solve crime, teachers use GIS to teach lessons in geography, etc.

d) Methods

A successful GIS operators according to a well designed implementation plan and business rules, which are the models and operating practices unique to each organization.

e) Software

It provides functions and tools needed to input and store geographic information. All GIS software packages rely on an underlying database management system for storage and management of the geographic and attribute data.

The functional components of GIS are:

1. Map (Data input system)
2. Data Storage and Retrieval System
3. Data Manipulation and Analysis System
4. Presentation
5. Data Output System

Map Projections : Spatial and Non-Spatial Data

As GIS is based on data, hence there must be a data model that has to be followed to standardize procedure. They are:

1. Spatial data models - Spatial data describes absolute and relative location of a geographic features and is classified as  (a)Raster Data  (b)Vector Data  (c)Image Data. A data model is a way of defining and representing real world surfaces and characteristics in GIS.
2. Attribute data or non-spatial data - Attribute data describes the characteristics of the spatial features which can be quantitative or qualitative in nature.

Data Models

Spatial Data Model

1) Vector Data Model: It uses discrete points, lines or areas corresponding to discrete objects with name or code number of attributes.

Advantages:

• Data can be represented at its original resolution and form without generalization.
• Graphic output is usually more aesthetically pleasing.
• Accurate geographic location of data is maintained.
• Since most data (eg. Hard copy maps) is in vector form, no data conversion is required.
• Allows for efficient encoding of topology, and as a result more efficient operations that require topological informations.

Disadvantages:

• Location of each vertex needs to be stored explicitly.
• For effective analysis, vector data must be converted into topological structures.
• Topology is static and any updating or editing of the vector data requires rebuilding of the topology.
• Algorithms for manipulative and analysis function are complex and may be processing intensive.
• Often this inherently limits the functionality of large data sets.

2) Raster Data Model: It is a regular grid of cells divided into rows and columns. An element of the  grid cell is to called a pixel (picture cell).

Advantages:

• It is a simple data structure.
• It has the ability to represent continuous surfaces and performs surface analysis.
• The ability to uniformly store points, lines, polygons and surfaces.
• The ability to perform fast overlays with complex database or sets.
• Also compatible with digital satellite imagery.

Disadvantages:

• There can be spatial inaccuracies due to limits imposed by raster data set cell dimension.
• Raster datasets are potentially very large. Resolution increases as the size of cells decreases. Thus cost and disk space used also increases.
• There is also a loss of precision that accompanies restructuring data to a regularly spaces raster cell boundary.
• Raster maps normally reflects only one attribute or characteristic for an area.

Raster	Vector
1) Simple data structure.	More complex structure.
2) Overlay operations are easily and effectively implemented.	2) Are more difficult to implement.
3) High spatial variability is efficiently represented in a raster format.	3) Representation of high spatial variability is inefficient.
4) Raster data structure is less compact.	4) Vector provides more compact data structure.
5) Topological relationships are more difficult to represent.	5) Provides efficient encoding of topology.
6) Manipulation and enhancement of digital images can be effectively done.	6) Cannot be effectively done in the vector domain.

Non-spatial data (Attribute Data Models)

Attribute data is information appended in tabular format to spatial features. A separate data model is used to store and maintain attributes data for software.

Data Input

Data Input Techniques

The input of attribute data is usually quite simple. The discussion of data input techniques will be limited to spatial only. There are at least 4 basic procedures for inputing spatial data in GIS.

1. Manual Digitizing - While considerable work has been done with newer technologies, the overwhelming majority of GIS spatial data entry is done by manual digitizing. The coordinates are recorded in a user defined coordinate system or map projection. Latitude and longitude is most often used. The ability to adjust or transform data during digitizing from one projection to another is a desirable function of the GIS software. Numerous functional techniques exist to aid the operator in the digitizing process.
2. Automatic Scanning - A variety of scanning device exists for the automatic scanning or capture of spatial data. We can capture spatial features from a map at a rapid rate. Large data capture work are done using scanning technology. Scanners are generally expensive to acquire and operate.
3. Coordinate Geometry - The input of spatial data involves the calculation and entry of coordinate geometry (CoGo) procedures. This input technique is very costly and labor intensive and is rarely used for natural application in GIS. It is more appropriate for land record measurement.
4. Conversion of Existing Digital Data - Conversion of existing digital data is  being increasingly popular. A variety of spatial data including digital maps are openly available from a wide range of government and private sources. The most common digital data to be used in a GIS is data from CAD systems. A number of data conversion programs exists, mostly from GIS software vendors to transform data from CAD to a raster/vector format.

Data Source

Two types of data are input into a GIS, spatial and attribute data. The data input process is the operation for encoding both types of data into the GIS database formats. A wide variety of the data source exists for both spatial and attribute data. 

The most common general source for spatial data are:

1. Analogue maps
2. Imageries
3. Global positioning system
4. Statistical data
5. Existing digital data files

Existing hardcopy maps provide the most popular source for GIS project.

Data Analysis

Geographical analysis reveals new or previously unidentified relationships within and between data sets, thus increasing our understanding of the real world. Geographical analysis module usually contains 4 important function:

1. Selection is a simple operation
2. Manipulation has to do with aggregation, buffering, overlaying and interpolation.
3. Exploration is the 1st step in discovering any kind of pattern or cluster in a data set.
4. Confirmation can be seen as a tool for estimation of process models, stimulation and forecasting.

Types of GIS analysis

1. Spatial measurements: Spatial measurements can be the distance between two points, the area of a polygon or the length of a line or boundary.
2. Information retrieval: With a GIS we can point at a location, object or area on the screen and retrieve recorded information about it.
3. Searches by attribute: As most GIS systems are simply built on the existing capabilities of a database system, searches by attribute are thus controlled by the capabilities of database manager.
4. Searches by geography: GIS spatial retrieval is the generating maps which allows searching for information visually and highlights the results.
5. The query interface: User must interact with the data in appropriate way. To do that we need the query interface.
6. Spatial overlay: The way to identify spatial relationships is through the process of spatial overlay.
7. Boundary analysis: It is often referred to as districting which helps define regions according to certain criteria.
8. Buffer Analysis: Used for identifying areas surrounding geographic features.
9. Neighborhood operations: Can evaluate the characteristics of the area surrounding a specific location.

Data Output

The operation of presenting results of data analysis in a form that is understandable to a user, or in a form that allows data transfer to another computer system is called data output.

Remote Sensing Applications

Can be useful and employed in almost area. Some major areas are,

1. Agriculture : Satellite and airborne images are used as mapping tools to classify crops, examine their health and viability and monitor farming practices. Agriculture application of remote sensing includes crop type classification, crop condition assessment, crop yield estimation, mapping of soil management practices, etc.
2. Forestry : Includes reconnaissance mapping, commercial forestry and environmental monitoring, etc. Objectives to be met by national forest/environment agencies include forest cover updating, depletion monitoring and measuring biophysical properties of forest stands, forest cover type, etc.
3. Land cover and land use : Resource managers involved in parks, oil, timber and mining companies are concerned with both land use and cover, as are local resource inventory or natural agencies. Land use application of remote sensing include natural resource management, wildlife habitat protection, routing and logistic planning for seismic/exploration/resource extraction activities, etc.
4. Hydrology or water resources : Offers a synoptic view of the spatial distribution and dynamics of hydrological phenomena. Examples of hydrological applications includes wetlands mapping and monitoring, soil moisture estimation, measuring snow thickness, flood mapping and monitoring, glacier dynamics monitoring, irrigation scheduling, etc.
5. Snow and Glacier : The snow bound areas in the Himalaya lie at high altitudes where the terrain is rugged and inaccessible which causes the conventional methods of study not only difficult but hazardous as well. Remote sensing techniques, therefore, have a vital role to play in these studies for quick results with much less cost. Visual interpretation of Landsat imagery and use of aerial photographs for glacier inventory is facilitating in snow and glacier study.
6. Wetland management : To better manage and conserve wetland resources, we need to know the distribution and extent of wetlands and monitor their dynamic changes. Wetland maps and inventories can provide crucial information for wetland conservation, restoration, and management. Geographic Information System (GIS) and remote sensing technologies have proven to be useful for mapping and monitoring wetland resources.

Unit-8 : Computer Security (Notes of TU BSc. 4th Year Computer Science)

Computer Security

Syllabus : Introduction; Security threat and security attack; Malicious software; Hacking; Cryptography (symmetric key and public key); Introduction to Firewall; Users identification and Authentication; Security awareness; Security policy; Antivirus and Antispyware.  

Computer security is about securing a computer system (desktop or laptop) or a host. It is about securing a computer system which ensures a computer free of danger and contains no virus by using anti-virus software.

We need computer security because:

• It maintain confidentiality, availability, and integrity of data.
• It prevent electronic mail form getting hacked and unauthorized access.
• It protects easy passwords and pins being cracked.
• It eradicates vulnerabilities in the system or data. 

Security Threats

Security threat is possible danger that might explode vulnerabilities in a computer system to breach security and thus cause possible harm. Simply security threat is the interaction of actor, motivation and vulnerability.

A threat is something that may or may not happen but has potential to cause serious damage. A threat can be either intentional or accidental. Intentional threats are normally due to intelligent person like crackers, hackers or criminal organizations. On the other hand, accidental threats are due to malfunctioning of computer users. A threat can cause damage through unauthorized access, destruction, disclosure, modification of data or denial of service.

The four types of security threats are:

1. Interception : It refers to the situation that an unauthorized party has gained access to a service or a data. Example : communication between two parties has been overheard by someone else.
2. Interruption : It refers to the situation in which services or data become unavailable, unusable, destroyed and so on.
3. Modification : It involve unauthorized changing of data or tampering with a service so that it no longer adhere to its original specifications.
4. Fabrication : It refers to the situation in which additional data or activities are generated that would normally not exists.

Security Attack

Security attack is any attempt to destroy, expose, alter, disable, steal or gain unauthorized access.

Intruders first of all analyze our environment and collect informations in order to exploit vulnerabilities and then perform desired type of attack in our computer system.

Our networks and data are vulnerable to any of the following types of attacks:

1. Passive attacks : An attack that attempts to learn or make use of information from system but does not affect system resources is called passive attack. It results in the disclosure of information or data files to attacker without the consent or knowledge of the user.
2. Active attacks : An attack that attempts to alter system resources or affect their operation is called active attack. It results in the disclosure of data files, medication of data.
3. Insider attacks : An attack initiated by an entity that is authorized to access system resources but uses them in a way not to approved by those who granted the authorization is called insider attack.
4. Outsider attack : An attack initiated by an unauthorized or illegitimate user of the system is called outsider attack.

Malicious Software

Malicious software (commonly known as Malware) is any software that brings harm to a computer system. It can be used to disrupt computer operation, gather sensitive information or gain access to private computer systems.

Malicious software can be in the form of worms, viruses, trojans, etc. which steal protected data, delete documents or add software not approved by users.

Worms:

This type of malware uses network resources for spreading. This is called worms because of its peculiar feature to creep from computer to computer using network, mail and other informational channels. Worms intrude our computer, calculate network address of other computers and send these to these addresses its copies.

The biggest danger with a worm is its capability to replicate itself on your system, so it could sent out hundreds or thousands of copies of itself creating a huge devastating effect.

Due to the copying nature of a worm and its capability to travel across networks, the end result in most cases is that the worm consumes too much system memory, causing web servers, network servers and individual computers to stop responding.

Father Christmas is an example of worm. It was distributed in 1987 and was designed for IBM networks.

Virus:

A computer virus is a program that inserts itself into one or more files and then performs some (positive null) action. It works into two phase.

1st - the virus inserts itself into a file, is called the insertion phase

2nd - it performs some action and is called execution phase.

It is important to note that a virus cannot be spread without human action.

The brain virus, written for IBM PCs is an example of this category.

Trojan horse:

They are the files that claim to be something desirable but, in fact are malicious codes or logic.

The trojan horse at first glance will appear to be useful software but will actually damage once installed or run on your computer.

Trojans are also known to create a backbone on your computer that gives malicious users access to your system.

A program named “waterfall.scr” serves as a simple example of a trojan horse.

Hacking

It is the practice of modifying the features of a system in order to accomplish a goal outside of the creator’s original purpose.

A hacker is someone who seeks and exploits weakness in a computer system or computer network.

Hackers may be motivated by a multitude of reasons such as profit, protest, challenge, enjoyment or to evaluate those weakness to assist in removing them.

Hacking practice can either be ethical (who don’t violate its security and credentials) or unethical (crackers).

Categories of Hackers:

1. Black hats : The type of hackers that violate computer security for personal gain such as stealing credit card numbers or harvesting personal data for sale to identity thieves, etc.
2. White hats : They are opposite of black hat hackers. They are ethical hackers, experts in compromising computer security systems who use their abilities for good, ethical and legal purpose rather than bad, unethical and criminal purpose.
3. Grey hats : They falls between black and white. They don’t work for their personal gain but they may technically commit crimes.

Cryptography

Cryptography is the art and science of making crypto system that is capable of providing information security. Cryptography deals with the actual securing of digital data. It refers to the design of mechanisms based on mathematical algorithms that provide fundamental information security services.

It is the science of providing security for information. It has been used historically as a means of providing secure communication between individuals, government agencies and military forces.

Today cryptography is a cornerstone of the modern security technologies used to protect information and resources on both open and closed networks.

The word cryptography means “secret writing” and is the art and science of information hiding. In ancient days, it was mostly referred as encryption (readable plain text to unreadable) and decryption.

Types of cryptography:

Secret/Symmetric Key	Public Key
Same key is used for encryption and decryption. Key must be kept secret.	Different keys are used. Key used for encryption is called public key and for decryption is called private key.
Encryption and decryption process is more faster than public key.	Slower.
It cannot be used for other systems than achieving confidentiality.	Can also be used in digital signatures and authentication systems.
Secrecy of the system entirely depends upon shared secret key. So if the key is lost, then whole system will fail.	Relatively more secure than private key.
Useful in the system where it is possible to share the secret key by meetings.	Useful when communication parties are at distant location and is difficult to share secret key.
It is feasible when numbers of users that is involved in communication is few.	Also feasible when the number of users that involve in communication is large.
Examples : caesar cipher, transportation cipher, etc.	Examples : RSA algorithm, EIGamal, etc.

Firewall

Firewall is a system designed to prevent unauthorized access to or from a private network. It can be implemented In both hardware and software or a combination of both.

Hardware firewalls can be purchased as a stand alone product but are also typically found in routers and should be considered as important part of system and network set-up. Software firewalls are installed on your computer.

There are several types of firewall techniques that will prevent potentially harmful information from getting through.

1. Packet Filter : It is typically set up of a list of rules based on matches to fields in the IP or TCP header. They are usually part of router.
2. Application Gateway : It applies security mechanism to specific applications such as FTP and Tenet servers. It is also called application proxy or application level proxy.
3. Circuit Level Gateway : It works at the session layer of OSI model or transport layers of TCP/IP protocol suite. The information that is passed to remote computer through circuit level gateway will appear as if originated from gateway.
4. Stateful Inspection Firewall : It keeps track of the state of network connections and is able to hold significant attributes of each connection in memory.

Basic purpose of firewall:

• It blocks incoming data that might contain a hacker attack.
• It hides information about the network by making it seem that all outgoing traffic originates from the firewall rather than the network. This is called Network Address Translation (TAN).
• It screens outgoing traffic to limit internet use and/or access to remote sites.

User Identification and Authentication

It is the process of determining and providing user identity. The process of authentication is often considered to consist of two distinct phases : identification and authentication.

Identification occurs when a user claims an identity. Authentication is the process of providing an identity and it occurs when subject provides appropriate credentials or evidences to prove their identity.

There are typically three components involved in the process of user authentication. They are:

1. Supplicant : The party in the authentication process that will provide its identity and evidence for it, and as a result will be authenticated.
2. Authenticator : It is the server that is responsible for verifying authenticity of users based on the evidence provided by him/her.
3. Authentication Database : It is the database that stores identity and other attributes that the user possesses. User need to provide these attributes to prove his/het identity.

Methods of Authentication

1) Password based authentication:

Passwords are an example of an authentication mechanism based on what people know. The user supplies a password and the computer validates it.

A password is an information associated with an entity that confirms the entity’s identity. It can be sequence of characters and digits or sequence of words such as phrases. Password can be used in storage in many ways such as in plain text form, in encrypted form or in the form of hash value of password.

2) Smart card based authentication:

A smart card is a small plastic cards, about the size of a credit card containing an embedded microchip that can be programmed to store specific user authentication information.

Smart cards help to eliminate the threats of hackers stealing stored or transmitted information from a computer. The information is processed on the smart card, so the authentication information is never transmitted to another machine.

3) Biometric based authentication:

It is a type of a system that relies on the unique physiological or behavioral characteristic of individuals to verify for secure access t electronic systems.

Some of the widely used physiological or behavioral characteristics are faces, fingerprints, voices, DNA structure, etc. Among all, biometric is the most secure and convenient authentication tool. It can’t be borrowed, stolen or forgotten but demerits are they are slow, intrusives and expensive.

Security Awareness

Security awareness is about educating employees about corporate security policies and procedures for working with information technology. Employee should receive information about who to contact if they discover a security threat and be taught that data as a valuable corporate asset.

By educating employees, suppliers, partners and customers, we can reduce the chances of securing threats and ensure that that all the staffs can properly handle an incident if it occurs.

Security Policy

Security policy is just a statement about what is allowed and not allowed to do in a system while security mechanism is a procedure how to implement the security policy. Policies may be presented mathematically, as a list of allowed (secure) and disallowed (non-secure) states.

Formulating security policy:

It depends upon the needs of particular organization. Main purpose of security policy is to secure organizational resources. Following steps id followed while formulating security policy.

• Analysis of existing security policy
• Identification of resources that needs to be secured
• Identification of possible security threats and attacks
• Formulation of possible security policies
• Evaluation of alternatives
• Selecting the best among alternatives

Antivirus and Anti-spyware

Anti-virus programs scan for viruses and related malware by examining the files on system for patterns of data that have been identified as being viruses. On some regular basis the database of patterns the programs use is updated to contain the latest information on known viruses.

Anti-spyware programs monitor system as someone use it for actions that are known to be spyware-related. For example, an anti-spyware program might trap attempts to change browser home page, or attempts to install software that starts automatically.

Anti malware applications

It is a type of software program designed to prevent, detect and remediate malware infections on individual computing devices and IT systems. The term antivirus software and anti-malware software are often used as synonyms. It provides or protects against infection caused by many types of malware, including viruses, worms, trojan horses, etc.

Unit-7 : Multimedia (Notes of TU BSc. 4th Year Computer Science)

Multimedia

Syllabus: What is Multimedia? What is Multimedia Computer System? Multimedia Components (Text, Graphics, Animation, Audio, and Video) Multimedia Applications 

Multimedia is the field concerned with the computer-controlled integration of texts, graphics, drawings, videos, animation, audio, and any other media where every type of information can be represented, stored, transmitted, and processed digitally. Multimedia must possess the following four basic characteristics;

1. Must be computer-controlled
2. Should be integrated
3. Must represent information digitally
4. Must provide an interactive interface to presentation

A multimedia application is an application that uses a collection of multiple media sources. Example: text, graphic, image, audio, animation, and video. It can be divided into three categories,

1. Information System
2. Remote Representation
3. Entertainment

Multimedia Computer System

A multimedia computer system is a computer system capable of processing multimedia data and applications. Multimedia computer system is capable of processing and interpreting two or more components of multimedia which includes text, graphic, animation, audio, and video. One of the main requirements of multimedia systems is real-time operation. Multimedia computer system usually requires a fast processor, large storage, graphic cards, and fast input/output devices.

Multimedia Components

As multimedia is a combination of more than one type of media or elements, key elements of multimedia are as follows:

Text

It is basic for word processing programs and is still the fundamental information used in many multimedia programs. In fact, many multimedia applications are based on the conversation of a book to a computerized form.

Text is a combination of alphabet symbols, digits, punctuations, etc. In multimedia applications, other media or screens can be linked through the use of text. This is called hypertext. Text in a multimedia system can express specific information or it can act as support for the information contained in other media items.

Data say textual or numerical is easy to represent using general characters but it is difficult to represent in computers so binary digit coding for text representation is IRA (International Reference Alphabet) coding. It is also called the ASCII code. UNICODE is another mechanism that includes larger sets of characters and uses 16 bits for each character.

Graphics (Images)

It refers to any computer program that makes a computer capable of displaying and manipulating pictures. Graphics make the multimedia application attractive and help to illustrate ideas through static pictures. Digital image files use a variety of formats and file extensions. Among the most common are JPEG, GIFs, PNG, etc.

Graphics design software such as photoshop and point.net allows developers to create complex visual effects with digital images. There are two types of graphics used:

I) Bitmaps (Raster images)

An image is represented as a two-dimensional array of “spots” (pixels). Pixel stands for picture element and is the smallest element of the monitor. Every pixel is represented by a group of bits. Therefore it is also called the “bitmap” image.

It can contain any number of colors but we distinguish between four main categories:

1. Linear - only two-color (black and white)
2. Grayscale image - (pure black and white)
3. Multi tones - (two or more colors)
4. Full-color images - (RGB, CMYK)

The size of raster images is determined by the following two factors, a) resolution and b) color depth.

II) Vector graphics

An image is represented as a collection of straight and curved line segments. Here the image is described as a collection of line segments. Vector images are simply combinations of lines and curves. CDR, PS use vector images.

Audio

It has a greater role to play in multimedia development. It gives life to the static of multimedia. Incorporation of audio is one of the most important features of multimedia which enhances multimedia usability. 

The application of audio service is telephone communication, telemarketing, voice mail, entertainment radio, etc. Audio formats include MP3, WMA, Wave, MIDI.

The quality of sound is characterized by bandwidth used. Voice of telephone uses 3000Hz of bandwidth, the voice of teleconferencing used 7000Hz and for better quality 15000Hz is used.

A sound wave is characterized by the following characteristics:

• Amplitude
• Frequency
• Bandwith

Videos

Video clips can be combined with the audio, text, graphics for multimedia presentation. Video is the sequence of images over time. Video conferencing, television, multimedia, CCTV, etc. are the application of video communication. The size of the video is much higher than that of the image. Common digital video formats include flash, MPEG, MP4, AVI, etc. which re actually compression techniques used with videos.

Animation

It is a simulation of movement created by displaying a series of pictures or frames. Cartoons on television are one example of animation. Animation on computers is one of the chief ingredients of multimedia presentations.

Video is live or real footage of an event taken with a video camera. But animation is a computer-generated moving picture produced in either two or three dimensions by using the software.

• It can draw the user’s attention and can also explain the things in detail and a better way.
• It can help users to visualize the 3D nature of the object.

The most common tool for creating animations is Adobe Flash.

Applications of Multimedia

We are familiar that using multimedia makes things clear, easier to understand, and more informative. Some of the areas are:

1. Education and Training: Computer Based Training (CBT) is a type of multimedia product which allows users to learn at their own pace.
2. Product Promotion: Advertising is perhaps one of the biggest industries that use multimedia to send their message to the masses.
3. Engineering: Computer-Aided Design (CAD) is used by engineers where they can view the design from many aspects and improve on it before production.
4. Leisure and Entertainment: Multimedia systems designed for leisure and entertainment are generally classified as computer games.
5. Information Provision: A multimedia encyclopedia is an example of a multimedia system used to provide information.
6. Virtual Reality and Simulations: Flight simulators are used to train pilots.

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