151 Oasis Radiant Computer Science, Book 7 Ring Topology In Ring network, each node is connected to two adjacent nodes in the form of a closed ring. In ring topology, the last node connects to the first node to complete the ring. Each node has a dedicated point-to-point connection only with the two devices on either side of it. In this network, data is communicated in one direction from node to node around the entire ring. When a computer in ring network sends message to another computer on the network, the message travels to each node or computer until it reaches its destination. The ring network configuration is shown in the figure above. Bus Topology In bus network, all nodes are connected to a common communication medium using central cable. The central physical cable that connects the nodes is called Bus. The data is communicated between nodes in both directions through bus. A bus topology uses the multipoint connection. The central single cable acts as backbone to link all the devices to the network. In bus network, when a computer sends a message to another computer it also attaches the address of the destination computer. Ring Topology Bus Topology
Oasis Radiant Computer Science, Book 7 152 In LAN, bus topology is mostly used. In this topology, each computer is assigned a unique address. The bus network configuration is given in the above figure. Mesh Topology In this topology, every node has a dedicated point-to-point connection to every other node on the network. In mesh network, each node is directly connected to all nodes on the network. This type of network involves the concept of routes. In this type of network, each node may send a message to the destination through multiple paths. It means that each node of mesh network has several possible paths to send and receive message, but in Bus, Star and Ring topologies each node has only one path. Key Points • Connection of multiple computers to share the resources is called computer networking. • User is allowed to share hardware, software, people and data resources using networking system. • A node is a connection point of networking system that can generate process and transfer data. • Server computer hosts all networking system. It serves the disk space, file and data to other users. • Client is user terminal who utilises the resources given by the server. Client has its own disk space, file and data but if required it gets from the server. Mesh Topology
153 Oasis Radiant Computer Science, Book 7 • Basically there are two sides on networking, server side and client side. • Some components required to connect computer networking are network interface card (NIC), server and client computers, communication media, network connecting devices and signal conversion devices. • A client server network is a network where at least one computer works like server that controls other computers which work like client. • Peer to peer network is simple connection of computers where all computers work like server and clients. • Network topology is the connection configuration of computers in a network structure. • Wide area network (WAN) connects the computers that span multiple geographic locations. • MAN (Metropolitan Area Network) connects the computers that spans on different locations of a metropolitan city. • LAN (Local Area Network) connects the computers in a limited location, such within a building or near by a building in a locality. Exercise 1. Answer the following questions. a. What is computer networking? b. Write any five advantages of computer networking. c. Write any three disadvantages of computer networking. d. List the devices required to connect computer networking system. e. Draw a labelled diagram of typical networking structure. f. What is MAN? g. What is network topology? Write its types. h. Explain the types of computer network on the basis of geographical location. i. What is WAN? Explain with example.
Oasis Radiant Computer Science, Book 7 154 2. Write short notes on: a. Server computer b. Star topology c. Wide Area Network (WAN) d. Local Area Network (LAN) e. Communication media. f. Mesh topology g. Communication media h. Node i. Client 3. Differentiate between: a. Stand alone computer and network system. b. Server and client. c. Wired and wireless communication media. d. LAN and WAN. e. Star and Bus topologies. 4. Write the full form of: a. WAN b. NIC c. LAN d. MoDem e. MAN 5. Fill in the blanks. a. Simple network configuration that describes the connection style of computer is called __________. b. Wired communication media are also called __________ medium. c. Main host computer is called __________. d. All the connection points are called __________. e. Internet is the example of __________. f. Network within a building is called __________.
155 Oasis Radiant Computer Science, Book 7 g. __________ is a network between the computers of a city. h. __________ is a signal conversion device that converts analogue signal to digital. i. __________ is a device that connects computer on star topology. j. Server serves the __________ space to clients. 6. State True and False. a. Server computer is working terminal in a network system. b. MAN is metropolitan area network. c. The full form of NIC is Network Integration Card. d. Topology gives the concept of network connection style. e. There is a server and client structure on all types of network. f. Full form of MoDem is Modulator/Demodulator. g. Node is the connection point of clients on computer network. h. Internet is wide area network. i. Bus topology uses hub. j. User works on server side of network. 7. Class Activity and Project Work a. Make a list of devices used in the networking system of your lab. b. Draw a typical diagram of networking used in your school. c. Write any two application areas of WAN, LAN and MAN. (Refer: bank, school, enterprise, government office etc.) d. What type of topology is used in a networking system of your lab? e. Make a list of merits and demerits of networking system used in your school.
Oasis Radiant Computer Science, Book 7 156 Internet and Email 11 Chapter 8 The concept of internet 8 Some terms used in the study of internet 8 The concept of e-mail 8 Browsing and searching websites
157 Oasis Radiant Computer Science, Book 7 Internet Internet is defined as the International Network which is the network system of various networks. It exists in global form. We can connect to the internet on the basis of standard rules, regulations and structure. The standard rules and regulations adapted to build the network structure are called protocols. Use of Internet Since internet has become a major part of the society and business sector, different institutions should use this application as a major tool to integrate with supplier, customer and other business environment. Here are some major application areas of internet in business and service sector: • For communication between different users and institutions using email, internet etc. • For entertainment -- we can browse different web sites and communication system on the internet for entertainment. • For online news publishing and processing. • For promoting online services and commerce called e-commerce. • For online education and training. Internet and Email 11 Chapter
Oasis Radiant Computer Science, Book 7 158 Requirement to Connect Internet We know that the internet is a global networking system so it is essential to connect the internet as the other network structures are connected. Basically we need the following devices and system to connect the network structure. 1. Computers: We need a working computer system and internet access devices to connect to the internet. Other devices are mobile phone, laptop computer, PDA (Personal Digital Assistant), etc. 2. ISP (Internet Service Provider): ISPs provide the user name and password to get access to the internet system. User should pay some amount to the ISP and get the access rights to the internet. 3. Signal Conversion Devices: We have to use signal conversion devices on the internet so that it is easy to convert analogue data to digital data and vice versa to process with the internet system. For example MoDem (Modulator and demodulator), Router etc. MoDem is a popular device that is used to modulate and demodulate the signals i.e. convert digital to analogue and analogue to digital. 4. Communication Medium: We have some path to transfer data from one location to another. These are called communication medium. We have two types of communication medium: Wired and Wireless. 5. Web Browser Software: We have to use web browser like Internet Explorer, Mozilla, and Netscape Navigator, or Google Chrome etc. to brows the internet.
159 Oasis Radiant Computer Science, Book 7 Advantages and Disadvantages of Internet Advantages The internet provides many facilities to the people. The main advantages of internet are: 1. We can share information by using the internet. 2. We can use internet for collection of information from different sources. 3. It is useful for publishing online newspaper. 4. It is effectively used for searching information related to business, jobs and other activities. 5. It is used for communication systems like internet phone, chatting etc. 6. It is used for entertainment for searching and downloading games and other audio visual programmes. 7. It is used for online education and training. 8. It is used for business promotion and e-commerce. 9. It is used for online ticketing system. Disadvantages Although the internet has many advantages, it also has some disadvantages. The main disadvantages are: 1. Viruses may spread using internet as the global network. 2. There is some security problem on internet data. 3. There is hacking and loss of data on internet. 4. User should filter the information before using the internet. 5. There is language problem to get an access to the internet. Basic Terms Web page: The World Wide Web consists of files called web pages which contain information and links
Oasis Radiant Computer Science, Book 7 160 to resources throughout the internet. It is an electronic document written in computer languages like hyper text mark up language (HTML). Web Site: It is a set of related web pages published by an organisation or individual. Normally it contains home page along with other additional web pages. It is addressed with special location name that is called web site address on the internet. Home page: It is the starting page or doorway to the web site like the table of content of book. It gives details about pages linked inside the website. Sometimes it is called index page or host page that contains so many links to get access to the multiple pages. Web Browser: Browser is a programme that displays web pages. It is the basic software that is needed to find, retrieve, view and send information over the internet. Uniform Resource Locater (URL): Each web page has a unique address called a Uniform Resources Locater (URL) that identifies its location on the internet. Basically the format of URL consists of four parts: Protocol, host computer, server or domain and file name. http://www.xyz.com/introduction.html Protocol: http (Hyper Text Transfer Protocol) Host computer: www (Word Wide Web) Domain Name: xyz Domain Type: com (Company) File Name: introduction.html
161 Oasis Radiant Computer Science, Book 7 Hyper Text: It refers to the text which connects to other documents. These texts are known as hyper text link, hyperlink or simply link. It is used to jump to another page or another part of the working page. ISP (Internet Service Provider): It is an organisation that provides the internet connection to different users. They charge some amount to the user and provide the internet service. They provide user name and password to access the internet system. In Nepal, popular ISPs are Mercantile Office System, Worldlink Communication, NTC, etc. Download and Upload: Download refers to the activities of copying a document, programme or other data from internet or other network structure to oone's own computer and working window. It is the “Pulling” of information from server to working window of the system. Uploading is the reverse process that place the information on the internet database. Email Electronic mail is a fast, easy and cheap way to communicate with others using the internet system. It is the basic service of internet. Email has a mail box address to which messages are sent and these are accessed from any part of the world at any time. There are two types of emails. These are web mail and SMTP (Simple Mail Transfer Protocol) mail. Web mails exist on the internet page like hotmail and yahoo mail. SMTP mail is available on outlook express, such as on windows system. We can compare the email and general post mail as below: E-mail Postal Mail Fast mailing Slow in comparison with e-mail Cheap Expensive Easy to send voice, images and other types of data Difficult to send multiple data
Oasis Radiant Computer Science, Book 7 162 Same message can be sent to several recipients at the same time. Same message has to be sent in different envelopes. Recipients can receive message from anywhere at any time. Recipients can receive message from specific points only. Email Address An email address is required to send and receive email. Email addresses are different from “mail” addresses. They usually consist of three parts: a user name, an “at” symbol (@), and a domain name. [email protected] 1. User name: sea_adhikari located to the left of the @ symbol, a user name identifies your account on the email server that handles the email. 2. @: Means “at” and separates your account name and the name of the mail server name. 3. Domain Name: hotmail.com. The domain name usually consists of two parts of identifying information. The first part is the name of the email server and is located to the right of the @ symbol like hotmail. The second part, usually a three-letter extension, indicates the top-level domain. They are separated by periods, ".", called dots like in ".com." Domains Top-level domains may help you know the type of organisation. Some meanings of domain are: Extension Meaning .com A company or business .org A non-profit or not-for-profit institution .gov Governmental agency .mil Military .edu Educational institution .net ISP or Network Provider Advantages of Emails • The delivery of message is very fast and sometimes almost instantaneous. It is similar for all locations, even overseas to a next door neighbour.
163 Oasis Radiant Computer Science, Book 7 • The cost of emailing is almost free. But it involves negligible amount for communication like phone and for ISP (Internet Service Provider). • Multiple copies of the same message can be sent to different people. • Pictures, files and other multimedia data can be attached with email. • It helps to enhance the communication system of user. Disadvantages of Emails • Although e-mail is delivered on time, receivers may not read their mails on time. • User should stay online to read and write more mails. • The system is totally based on the internet or other network based system. So failure of network may discontinue the email services. • It is knowledge based application so all users are not able to use this system. • Sometimes some unnecessary mails called junk mails may mislead the user. Searching Educational Materials using Website. Internet is the collection of unlimited information arranged in a systematic order. You can search required information on the internet. There are some search engines available on internet. They are called search engines. Popular search engines are Google, AltaVista, and Search.com etc. Google.com is a very popular search engine for information on the internet. Suppose you want to search for information about the History of computer. You can use Google.com with the following steps. - Connect the internet application - Open Web Browser like Internet Explorer - Type the web address as : www.google. com on the address bar of web browser. - Now type the topics to search on the
Oasis Radiant Computer Science, Book 7 164 internet and press OK. Suppose you want to search for information about the history of computer, type the history of computer on Google search bar and search: - Now you will get a list of titles related to history of computer as given in above figure. - Suppose you want to search the pictures of history of computer, you have to select the option Images on Google system and search it. You will get the list of figures as given in the figure below: Like the above example, you can search for educational materials related to science, health, math, social studies, etc. using the internet.
165 Oasis Radiant Computer Science, Book 7 Key Points • Network of networks existing on global form is called the internet. • A big network that integrates various computers from different parts of the world to share the resources globally is called the internet. • To connect to the internet, we need computers, internet service provider (ISP), signal conversion devices like modem, router, communication medium like wired and wireless system and web browser. • There are two types of internet connection technology. These are dialup connection that use a telephone line to connect internet and broadband connection which uses TV cable or other broadband system like ASDL (Asymmetric Digital Subscriber Line), WIFI (Wireless Fidelity). • Collection of web pages addressed with a unique location is called website. • Internet page that consists of different information in the form of text, audio, video, animation etc. is called a web page. • Main index page that contains the links to multiple web pages is homepage. • Programme that helps display the internet pages is called a web browser. Examples: Internet Explorer, Netscape Navigator, Google Chrome, Opera, etc. • Standard rules and regulations that maintain the standard application and structure of network are called protocols. • Internet service provider (ISP) is an organisation that provides internet services to users. • Process to place information to internet server is called upload and process to copy information from server and display on our working window is called download. • We can use internet in different sectors like chatting, telephone network, emails, website, e-commerce etc. • Selling and buying the goods and services using internet in digital form is called the e-commerce. • Payment by using digital data using debit card, credit card, e-cash, e-cheque etc. is called electronic payment.
Oasis Radiant Computer Science, Book 7 166 Exercise 1. Answer the following questions. a. What is internet? b. Write some advantages and disadvantages of internet. c. Define web browser. List some popular web browsers. d. What is downloading and uploading? e. What is website? f. What is URL? g. List the devices and system required to connect to the internet. h. What is e-commerce? Explain. i. What is Domain Name? j. What is protocol? Write the features of FTP. k. What is email? Explain its advantages and disadvantages. l. Write the use of internet in education sector. m. Define home page. 2. Write short notes on: a. Web site b. Downloading and uploading c. URL d. E-commerce e. Web pages f. Email 3. Differentiate between: a. Web page and web site b. Email and internet c. Upload and download d. Homepage and linked pages 4. Fill in the blanks a. Global network connection is called ____________. b. Process to copy information from internet to working system is called ____________. c. Process to place information on internet is called ____________. d. Web site is the collection of ____________. g. Full form of URL is ____________.
167 Oasis Radiant Computer Science, Book 7 h. Software system that helps to display web pages is called ____________. i. MoDem is ____________ conversion device. j. Company that provides internet service to the users is called ____________. 5. Write the full form of: a. PDA b. WWW c. HTTP d. ISP e. ADSL f. MoDem g. URL h. HTML i. Email 6. State True or False. a. Internet deals with the global network connection by collecting so many local networks. b. Internet is international network which distributes information globally. c. E-mail system helps to send and receive electronic mails. d. Selling and buying goods and services using Internet is called electronic commerce. f. Webpage is the collection of websites. g. Internet service providers give internet service. h. Signal conversion devices convert the analogue to digital and digital to analogue signals. i. Web browser is software that displays websites. j. Pulling information form internet is called downloading. k. Crimes committed using internet system are called cyber crimes. 7. Class Activities and Project Work a. Collect some articles from daily newspapers and prepare a project report about use and application of internet in banking sector. b. Find out the internet connection technology in your school. List its advantages and disadvantages over other technology. c. Do you know about social network? Give an example of why and how you use such network.
Oasis Radiant Computer Science, Book 7 168 Number System 12 Chapter 8 Types of number system 8 Process to convert decimal to binary number 8 Working with octal number 8 Working with hexadecimal number Decimal Binary 0 0 1 1 2 10 3 11 4 100 5 101 6 110 7 111 8 1000 9 1001 Decimal Octal Hexadecimal Binary 0 0 0 0000 1 1 1 0001 2 2 2 0010 3 3 3 0011 4 4 4 0100 5 5 5 0101 6 6 6 0110 7 7 7 0111 8 8 1000 9 9 1001 10 A 1010 11 B 1011 12 C 1100 13 D 1101 14 E 1110 15 F 1111 The number system having base 8 is called octal number system. It includes 8 digits: 0, 1, 2….., 7
169 Oasis Radiant Computer Science, Book 7 The number system has its own history. You cannot imagine life without numbers. Decimal number was developed in the 8th to 11th centuries AD by Hindu-Arabic mathematicians. There are different types of number systems used in electronics. They are decimal numbers, binary numbers, octal numbers and hexadecimal numbers. Decimal (Denary) Numbers The number system having base 10 is called the decimal number system. It includes 10 digits: 0, 1, 2….., 9 The number of base or radix 10 is called decimal number. It is the first number system in which all the ancient and modern mathematical calculations are done. Other number systems are derived from it. Our daily life transactions are done in the decimal system. Binary Number Binary number is a number of bases (radix) 2. It is represented by 1 and 0. The digits, 1 or 0, are called bits (binary digits). These numbers represent two logical conditions, TRUE and FALSE. Decimal Binary 0 0 1 1 2 10 3 11 4 100 5 101 6 110 7 111 8 1000 9 1001 Number System 12 Chapter
Oasis Radiant Computer Science, Book 7 170 Convert the following decimal into binary numbers: a) (45)10 = (101101)2 Remainder 2 45 1 2 22 0 2 11 1 2 5 1 2 2 0 1 b) (225)10 = (10111001)2 Remainder 2 225 1 2 112 0 2 56 0 2 23 1 2 11 1 2 5 1 2 2 0 1 Binary to Decimal Conversions a) (1110001)2 = (113)10 26 = 64 25 = 32 24 = 16 23 = 8 22 = 4 21 = 2 20 = 1 1 1 1 0 0 0 1 1 × 26 = 64 1 × 25 = 32 1 × 24 = 16 0 × 23 = 0 0 × 22 = 0 0 × 21 = 0 1 × 20 = 1 113
171 Oasis Radiant Computer Science, Book 7 b) Convert 10011011 into decimal equivalent. 1 × 27 = 128 0 × 26 = 0 0 × 25 = 0 1 × 24 = 16 1 × 23 = 8 0 × 22 = 0 1 × 21 = 2 1 × 20 = 1 155 \ (10011011)2 = (155)10 c) Convert the following binary numbers in decimal equivalents: a) 00111 b) 01011 0 × 24 = 0 0 × 23 = 0 1 × 22 = 4 1 × 21 = 2 1 × 20 = 1 (7)10 1 × 20 = 1 1 × 21 = 2 0 × 22 = 0 1 × 23 = 8 0 × 24 = 0 (11)10 d) Convert into decimal. a) 1001 = 1 x 23 + 0 x 22 + 0 x 21 + 1 x 20 = 8 + 0 + 0 + 1 = 9 b) 1101 = 1 x 23 + 1 x 22 + 0 x 21 + 1 x 20 = 8 + 4 + 0 + 1 = 13 Octal The number system having base 8 is called octal number system. It includes 8 digits: 0, 1, 2….., 7 The number with base 8 is called octal number. It is represented by Q or O. It was a very popular number system, especially used in the Digital Equipment
Oasis Radiant Computer Science, Book 7 172 Corporation PDP/8 and other old computers. It is rarely used today. The octal number system has eight numbers going from 0 to 7. Weighted value 85 84 83 82 81 80 32768 4096 512 64 8 1 Decimal to Octal Decimal number is repetitively divided by 8 and remainders are arranged in the form of octal numbers. Example Convert 240 decimal into octal. Remainder 8 240 0 8 30 6 3 (240)10 =(360)8 Octal to Decimal Each octal digit is multiplied by its weighted position. The sum of all products is known as decimal form of octal. Example: Convert 340 octal into decimal. (340)8 =3 x 82 + 4 x 81 + 0 x 80 = 192 + 32 + 0= (224)10 Convert 175 octal into decimal number. (175)8 = 1 x 82 + 7 x 81 + 5 x 80 = (125)10 Convert 35610 into base 8. 8 356 4 8 44 4 4 (365)10 = (444)8
173 Oasis Radiant Computer Science, Book 7 Hexadecimal The number system having base 16 is called a hexadecimal number system. It includes 16 digits 0, 1, 2….., 9,A,B,C,D,E. It is also called Hex number system. The number with base 16 is called hexadecimal number. It is denoted by H. It has 16 symbols starting from 0 to 15 ( 0,1,2,3,4,5,6,7,8,9,A=10,B=11,C= 12,D=13,E=14,F=15). The following table shows the relationship between hexadecimal and binary numbers. Decimal Octal Hexadecimal Binary 0 0 0 0000 1 1 1 0001 2 2 2 0010 3 3 3 0011 4 4 4 0100 5 5 5 0101 6 6 6 0110 7 7 7 0111 8 8 1000 9 9 1001 10 A 1010 11 B 1011 12 C 1100 13 D 1101 14 E 1110 15 F 1111 Decimal to Hexadecimal Conversion The decimal number is repetitively divided by 16 and remainders are collected to represent hexadecimal numbers.
Oasis Radiant Computer Science, Book 7 174 Example: Convert the following into hexadecimal number: (1047)10 = (417)16 Remainder 16 1047 7 16 65 1 4 Convert (333)10 into hexadecimal. Remainder 16 333 13 16 20 4 1 (333)10 = (14D)16 Hexadecimal to Decimal Each hexadecimal digit is multiplied by weighted positions, and sum of product is equal to decimal value. Example: (A 3 7 E)16 = (?)10 A × 163 + 3 × 162 + 7 ×161 + E × 160 Convert (1230)16 to decimal. = 1 × 163 + 2 × 162 + 3 ×161 + 0 × 160 = 4096 + 2X768 + 3X 16 +0 = (5680)10 A = 10 E = 14 = (41854)10
175 Oasis Radiant Computer Science, Book 7 Key Points • The first number system was the decimal number system which was developed by Hindu philosophers. • Decimal numbers are generated with the combination of 0,1,2,3,4,5,6,7,8,9. • Binary numbers are digital numbers generated with the combinations of 0 and 1. • Octal numbers are eight base numbers that are generated with the combination of 0,1,2,3,4,5,6,7. • Hexadecimal numbers are 16 base numbers and generated with the combination of 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F where A=10, B=11, C=12, D=13, E=14,F=15 • We can convert different numbers from one form into another form using simple calculations. 1. Answer the following questions. a. What is a decimal number system? b. What is a binary number system? c. Define the octal number system. d. Define the hexadecimal number system. e. Write the digorithm to convert octal to decimal with example. 2. Differentiate between: a. Binary and octal numbers b. Decimal and hexadecimal numbers c. Octal and binary numbers 3. State True and False. a. Octal numbers are two base numbers. b. Decimal numbers are ten base numbers. Exercise
Oasis Radiant Computer Science, Book 7 176 c. General arithmetic uses binary numbers. d. Electronic devices use binary numbers. e. Hexadecimal number is similar to octal number. 4. Solve the following: a. Convert the following decimal numbers into binary: i. 234 ii. 542 iii. 158 b. Change the following decimal into octal and hexadecimal numbers: i. 756 ii. 5164 iii. 51818 c. Convert the following hexadecimal numbers into decimal: i. 78AB ii. EFA25 iii. 9E2C iv. ABC d. Convert (333)10 into hexadecimal number. e. Convert the following numbers according to the given instruction: i. (240)10 into octal number i. (ABC)16 into decimal number f. Convert (356)10 into base 8. g. Convert (520)10 into base 16. h. Convert the following octal numbers into decimal i. 4532 ii. 6743 iii. 1234 iv. 2342 ii. Convert (A5B)16 into decimal number. iii. Convert the following binary numbers into decimal numbers. i. 101111 ii. 1101010 iii. 11111 iv. 10010100
177 Oasis Radiant Computer Science, Book 7 Computer Graphics 13 Chapter 8 The concept of Adobe Photoshop 8 The process to handle photo 8 Working with tool bar 8 Working with different menu
Oasis Radiant Computer Science, Book 7 178 Adobe Photoshop Photoshop is the leading professional image-editing programme, released by Adobe. Photoshop is useful for both creating and editing images to be used in print or online. Photoshop is the best choice for any image manipulation job because it is easy to use. How to start? Click the “Start” menu and go to the “Programs” folder. You will see an “Adobe” folder with “Photoshop 7.0” inside; click this icon. Computer Graphics 13 Chapter
179 Oasis Radiant Computer Science, Book 7 You will get the system of Photoshop. Menu Details of Photoshop We can view the main menu of Photoshop as given below: File– Create new images, open pre-existing images, print, exit the programme, etc. Edit – Undo, copy, paste, cut, preferences, basic image manipulation, etc. Image – Change the image or canvas size, rotate, adjust brightness & contrast, etc. Layer – Create/delete layers, merge layers together, layer effects, etc. Select – Adjust the selected area of your image. Filter – Apply filters and effects to your images. View – Zoom in and out of your images. Window – Open or close different windows within Photoshop Creating a New Canvas/ Image Working area of graphic design is called canvas. We have to create the new image on the new canvas. - Click on “File” menu and select “New” (or press Ctrl+N). A Window will display. Now select the required size of design or canvas and choose Ok.
Oasis Radiant Computer Science, Book 7 180 Your canvas will open as a blank, white window. Now make the design and save it. Opening a Pre-existing Image - Click on “File” menu and select “Open” (or press Ctrl+O). Find the image on your computer that you wish to edit, and click “Open.” Your image will open in a new window within Photoshop. Tools Used on Photoshop Once you have an image created or opened, you can edit or draw on top of it with Photoshop’s “Tools” window, which is the long, thin window that is automatically open on the left side. Here is a breakdown of all the tools contained on this bar: ● Marquee Tool – used for selecting areas of an image ● Move Tool – used for moving an image to a different area of the canvas ● Lasso Tool – used for selecting areas of an image that may not necessarily comprise of straight lines ● Magic Wand Tool – used for autoselecting large areas of an image that are similar in colour ● Crop Tool – used for reducing the image to a certain area (“cropping”) ● Slice Tool – used to “slice” an image
181 Oasis Radiant Computer Science, Book 7 into different sections; generally used for the creation of images for a web page design ● Healing Brush Tool – used to fix imperfections in an image by copying other pixels from the image. The Healing Brush tool will also match the texture, lighting, and shading to perfectly match the area you are fixing. ● Brush Tool – used with the mouse to simply draw lines on your image ● Clone Stamp Tool – used to “clone” or copy one area of an image to another; first hold “Alt” and click an area of the image to copy, then click on a different area to copy it there. ● History Brush Tool – used to copy and draw a pre-existing image in different artistic styles ● Eraser Tool – used to erase certain areas of an image ● Gradient Tool – used to create gradient fills for an image, of any colour ● Blur Tool – used to blur or blend areas of an image ● Dodge Tool – used to uniquely adjust the brightness and contrast of an image ● Path Selection Tool – used merge overlapping components into a single component ● Type Tool – used to place text on an image ● Pen Tool – used to draw lines and curves with better precision ● Rectangle Tool – used to draw rectangles and other polygons ● Notes Tool – used to leave notes for yourself on your image ● Eyedropper Tool – used to select and match specific colours ● Hand Tool – used to quickly view different areas of an image ● Zoom Tool – used to zoom in and out of an image ● Set Foreground/Background Colour – used to set the foreground (front) and background (back) colours of an image; can also be used to change the colours of text, etc.
Oasis Radiant Computer Science, Book 7 182 Cropping an Image If an image is too large and you would like to cut it to just focus on one section of the image, you can “crop” it to that size and area. - Select the “Crop” tool, and click and drag around the area you want. - You can resize the area with the mouse by clicking any of the corners. - Now press enter to crop the image. You will get the resized form of image. Resizing an Image If you don’t want to crop your image and you want the entire image, just at a smaller size, you can resize your image to any dimension you wish. - Select “Image Size” from the “Image” menu. - Select the width and height of the image. Note: The default in Photoshop is to keep image resizing at “Constrain Proportions.” This means that if the height is changed, the width will be changed at the same ratio.
183 Oasis Radiant Computer Science, Book 7 This keeps your image looking approximately the same, only at different sizes. If you wish to change this, just un-click the “Constrain Proportions” check box at the bottom of the “Image Size” window. You can change the image size either by pixels or percentages. You may wish to enlarge or reduce the size of your image. Enlarging image may reduce the quality of the image. Moving an Image You can move an image to any area of the canvas you wish. - Select the “Move” tool, and click and drag the image to any area of the canvas you wish. Selecting / Deleting a Part of an Image - Choose the “Marquee” tool. - Click and drag around a part of an image. A rotating, dotted line will surround that area. To delete this section that you’ve selected, hit the “Delete” key on your keyboard. Working with Magic Wand The “Magic Wand” can select a larger area of an image by grabbing
Oasis Radiant Computer Science, Book 7 184 similar looking pixels and grouping them together. Select the Magic Wand tool and click an area of an image. It will select a large portion of the area which you can move, delete, etc. Adding Text - Click the “Text” tool on the tool bar and click in your image where you want to add text. - The text will appear on top of the image, and it will be on its own new layer. You can change the font, style, size, antialiasing, and colour of your text on the menu directly below the main Photoshop menu. Brush / Pencil Tool The Brush tool can be right-clicked to also show the Pencil tool as an option. Both are very simple tools that allow you to directly draw on top of an image. Select a colour with the Foreground Colour option on the tool bar, and select a brush size from the tool’s sub-main menu, above. Click and drag across an image to draw on top of it. Clone Tool The Clone tool will copy pixels from one part of an image and copy them to a new part of the image. The Clone tool is most useful in situations such as removing blemishes from a face in a photograph, clearing a few clouds out
185 Oasis Radiant Computer Science, Book 7 of a bright blue sky, etc. - Choose the Clone tool. - Hold the “Alt” button on your keyboard, and click in an area of the image that you’d like to copy. - Now click elsewhere on the image, and move the cursor around. The image will “clone” itself to that second area. Eraser Tool The eraser simply deletes sections of an image. - Click the Eraser tool, and click and drag around your image. - The eraser will “erase” the image to what’s set as the Background colour. Gradient/Paint Bucket Tool The Gradient tool can be used on its own, or right-clicked to also select the Paint Bucket tool. A gradient is a horizontal fading of colours, most commonly used in the creation of banners for web pages. - Select the Gradient tool, the sub-main menu for a drop-down of available gradients. The default is the most common.
Oasis Radiant Computer Science, Book 7 186 Once you’ve selected which gradient you wish, just click and drag across your image. - The direction you drag (left to right, right to left, etc.) determines the flow of the gradient. The Paint Bucket lets you fill in a large section with the same colour. Select the Paint Bucket by right-clicking the Gradient tool, and click in an area of your image. It will fill with the colour selected as the Foreground colour. Blur Tool The Blur tool is useful for covering up small distortions in an image by blending the surrounding pixels together. To blur something, - Select the Blur tool. - Click and drag around the area you wish to blur. Rotating an Image
187 Oasis Radiant Computer Science, Book 7 You can rotate and flip your image in any direction you wish. In the “Rotate Canvas” list under the “Image” menu, there’s a wide variety of options to choose from. If you select “Arbitrary” for a rotation, a new window will appear asking you for the direction (clockwise or counter-clockwise) and the degree of the rotation. Zoom Tool If you find that you need to zoom in or out of your image for any reason, you can use the Zoom tool. Click the Zoom tool (it looks like a magnifying glass). If you click once on your image, it will zoom to double its size (100% to 200%, and so on). If you right-click, you can select the “Zoom Out,” which will reduce its size. Note that this doesn’t actually change the size of the image. It simply changes your view of the image on the canvas. Brightness & Contrast Sometimes when working with images, you may need to adjust the brightness and contrast. Photoshop makes this very easy. Select “Brightness/Contrast” from the “Adjustments” >> “Image” menu. A new window will appear allowing you to slide the brightness and contrast any way you wish. The Brightness/Contrast command lets you make adjustments to the overall tonal range of an image. Adjustments made here will affect every pixel in your image, unless a selection is made beforehand.
Oasis Radiant Computer Science, Book 7 188 Filters Photoshop has a wide variety of filters you can apply to your images. They include obvious ones such as blurring and sharpening, but also very advanced ones such as ripples, distortions, and rendering clouds. You can browse through the available filters by selecting the Filters menu. Work with the available filters, and remember that you can undo your actions at any time with the History window. Saving Images – PSD Format If you are working with a very complex image, you may want to think about saving it. Saving as a PSD file (Photoshop’s native format) allows you to open it up again with all the layers and such intact. If you save it as another type of image, Photoshop will “flatten” the image. To save your image as a PSD, just select “Save” from the “File” menu, and select a place on your hard drive or disk to save it. Saving as a GIF (Graphics Interchange Format) File Underneath “Settings,” select “GIF” from the drop-down menu. One of the most important features in this menu is the “Colors” setting. The more colours your image has, the more colours you should allow your GIF to have. However, since you want to create optimised images for the web, it is best to use as little possible colour as possible, while still saving a clear image. If your image has very few colours, you should change the colour setting
189 Oasis Radiant Computer Science, Book 7 to reflect the small number of colours. The smaller the number of colours, the smaller the file size the GIF will have. If you want, your image can have a solid outline colour. You can choose this by going to the “Matte” selection, and picking a colour. Other options in this menu need not be changed. These are standard defaults for saving GIFs. When you are ready, click “Save” and save the image by giving it a file name. Saving as a JPEG (Joint Photographic Expert Group) File Underneath “Settings,” select “JPEG” from the drop-down menu. Go to the drop-down menu with “JPEG High” displayed. There you can determine the quality of the image for the web. Naturally, higher quality images will have a larger file size. It is not necessary that images be of extremely high quality. Usually, “Medium” is a good setting to choose. To refine the quality of the image, use the “Quality” setting. Here, you can save the JPEG as a percentage of the original image’s quality. For example, 50% would be half the quality of the original image. When you are ready, click “Save” and save the image by giving it a file name. Key points • Photoshop is the design packaged software used to handle the photos and other design. • We can use Photoshop to handle photo for studio work and for the design. • The area where to draw the picture or handle photo is called canvas. • There are different formats of Photoshop file. • We can maximise and minimise the view of the working window of Photoshop. • History tool of Photoshop helps to go back to original pictures or design.
Oasis Radiant Computer Science, Book 7 190 1. Answer these questions. a. Write down the uses of Photoshop. b. How do we start Photoshop? c. What is canvas? d. How do we create new canvas? e. List out the tools used on Photoshop. f. Write the steps to resize the image. g. How do we work with magic wand? h. How do we add text on picture? Write steps of the process. i. What is blurring? Write the steps to blur a picture. 2. Write short notes on: a. Rotating image b. Zoom tool c. Eyedropper tool d. History tool e. Working with file format 3. Differentiate between: a. PSD format and Web format of file b. GIF and JPEG format of file c. History tool and Eyedropper tool d. Zoom in and Zoom Out Exercise • Picture quality depends on the number of pixels. The higher the pixel, better the quality. • We can resize the picture according to our requirement using image size option. • GIF format files are popular for web design. • JPEG format is popular for Photo graphic use. • PSD format is popular for design and publication.
191 Oasis Radiant Computer Science, Book 7 4. Give full form of: a. PSD b. JPEG c. GIF 5. Fill in the blanks: a. Photoshop is developed by …………….company. b. The working area of file is called ……………………. c. The higher the ………………..of image better the quality. d. To maximise the view is Zoom …………….. e. To hide or display some part of image is called ……….tool. 6. State true or false: a. Photoshop is used to prepare documents. b. Image quality depends on the number of pixels. c. Blur tool is used to increase the brightness of image. d. It is possible to write text on image. e. We can rotate the canvas of Photoshop file. 7. Lab and Project Work a. Open your photo and make it bright and balance the colour used on your photo. b. Crop the image according to your requirement. c. Use gradient tool to fill multiple colours. d. Design an advertisement format for "admissions open" announcement of your school. e. Rotate the canvas of your design. f. Draw different shapes using drawing shape tool. g. Use history tool to get the original image. h. Use filter tool to alter the shape of your image. i. Save your design to make PSD file. j. Save same design by making GIF and JPEG file.
Oasis Radiant Computer Science, Book 7 192 Multimedia Application 14 Chapter 8 The concept of multimedia 8 Uses of multimedia 8 Components of multimedia
193 Oasis Radiant Computer Science, Book 7 Introduction Multimedia is the use of any combination of text, graphics, audio and video aids in presentation of information. Different technologies of communication such as television, computer printer and video recorder can be connected to create multimedia applications of information with textual, graphic, audio and video presentations, etc. Components of Multimedia Multimedia is mainly concerned with the computer-controlled integration of text, graphics, drawing, video, animation and audio where every type of information can be represented, stored, transmitted and processed digitally. The key elements used in most multimedia applications include text, graphics, animation, sound, and video. • Text • Graphics • Animation • Sound • Video Text Humankind developed text and symbols so that they could communicate using them. In the past, content was produced primarily via text. Text is still an effective way to communicate. In multimedia, text is used as headlines, subtitles, and captions. Graphics It is a generic term used to describe the information using a pictorial form. It Multimedia Application 14 Chapter
Oasis Radiant Computer Science, Book 7 194 is very essential to use visuals, graphics, 2D and 3D images, for multimedia development. In fact, multimedia applications are based on graphics. Animation Animation refers to an arrangement of a sequence of images that change or move. Animation can provide information, add visual interest, or draw attention to important information in a multimedia application. Sound Computer and digital technology have changed the face of music industries. It is essential to add sound into a multimedia application. We can add this effect on the multimedia so that user can understand the information and enjoy it better with their ears. In multimedia applications, digitised sound is called audio. Video Video can do a great deal to enhance a presentation. It can easily illustrate a proper technique to prepare TV advertisement, film show and other clips related to some issues. The term video refers to the moving picture accompanied by sound such as a picture on TV or film. Multimedia Applications The multimedia is a very dynamic media of representation. It is applied in business, government agency, school, and home. Different application areas of multimedia are discussed below. Multimedia in Education Interactive CDs for science, mathematics, biology, computer and other subjects are available. They are important for all types of educational institutions today. The concept of distance learning is based on computer. Some universities provide multimedia CDs to their enrolled students. The CDs contain study materials, audio-video materials, which are, sometimes, impossible to get in a lecturer hall. Multimedia in Training Schools, colleges, business organisations, etc. use video clips, slide shows etc to train manpower. Driving, engineering process, airplane and spacecraft
195 Oasis Radiant Computer Science, Book 7 launching, monitoring and controlling, for example, are done today with models made through multimedia. Multimedia in Entertainment It is a medium of entertainment at home and office. The multimedia kits of game are available in market. Audio-video facilities are provided by multimedia kits. You can enjoy national as well as foreign films, music, etc. using multimedia. Multimedia in Advertisement It helps in advertisement of products for business organisations. The concept of e-commerce is needed not only for online purchasing, but also for advertising products amongst internet users. Multimedia in Presentation It is a strong medium of presentation of graphs, reports, and any other materials. Business organisations, training centres, and learning all depend on effective presentations. Multimedia in Business Communication Multimedia is used in business communication. It is a very powerful tool to maintain the quality of business communication. Business communication includes: customer information, product information, reports for investors, etc. Multimedia in Web Page Designing Multimedia is used for web page designing. The web page is attractive only if multimedia is used. Multimedia adds chart, graph, colour and sound, etc. Key Points • Multimedia is the use of any combination of text, graphics, audio and video to present the information. • Multimedia enhances the information presentation system and makes it easy to create a better learning environment in different sectors. • Multimedia is used in different areas such as education, training, entertainment and film making.
Oasis Radiant Computer Science, Book 7 196 • Basic elements of multimedia are: text, audio, video, animation, and graphics. • Video deals with the recording and displaying of images. • Animation deals with the movement of text, graphics and other images. • Audio deals with the recording and playing of sound with the help of a computer system. Exercise 1. Answer the following questions. a. What is multimedia? b. Have you used multimedia? Where have you used it? c. What is the role of multimedia in academic sector? d. Write the role of multimedia in communication sector. e. Discuss the components of multimedia. f. How is multimedia used in entertainment? g. Explain the role of animation for film making and advertisement design. h. Discuss the use of multimedia in the business sector. i. List some areas of use for multimedia. j. Discuss the role of graphics and animation for training. 2. Write short notes on: a. Animation b. Graphics c. Multimedia d. Use of multimedia in training 3. Differentiate between: a. Film and audio work b. Audio and video data c. Graphics and animation
197 Oasis Radiant Computer Science, Book 7 d. Multimedia and ordinary text e. Use of multimedia in education and business 4. Fill in the blanks. a. ____________ is the integration of audio, visual, text, animation, etc to represent the information. b. Recording and display of a sequence of images in a certain time frame to move an object is called ____________. c. We need ____________ configuration computer to work with multimedia. d. Graphics deals with display of ____________ for data presentation. e. Basic elements of multimedia are ____________, ____________, ____________ and ____________. 5. State True or False. a. Animation deals with video data. b. Synthesising, recording and playback of audio or sound to represent data is called audio data. c. Multimedia is applicable for designing advertisement. d. We need high configuration computer system to work with multimedia. e. Virtual reality is a technology which explains and defines the computer graphics and computer simulation programmes. 6. Class Activities and Project Work a. Discuss any five application areas of multimedia in your school. b. Discuss the types of data available in a third generation (3G) mobile phone. c. Explain the terms: MMS, SMS, web pages and GPRS. d. List the devices and software required to work with multimedia.
Oasis Radiant Computer Science, Book 7 198 Programming Tools and Techniques 15 Chapter 8 The concept of programming 8 Algorithms and their uses to develop programme 8 Flowchart with its uses for programming Terminal Symbol Input / Output Symbol Processing Symbol Decision Symbol Connector Symbol Data Flow Line Start / End Input / Output Data Process Decision Connect Read the value for n Start Display ‘n is odd number’ Display ‘n is even number Yes End No is rem =0 Calculate, rem = n%2 Flowchart
199 Oasis Radiant Computer Science, Book 7 Introduction We know that a computer is a user dependent machine. It does not think and work by itself. All the activities of a computer are controlled and processed by the instructions and information provided by the user. These instructions are called commands. Collection of such instructions and data in a systematic form to solve a particular problem is called a programme. To use a computer to solve problems, we have to make some systematic plans of action. Such plans of action can be represented in a systematic order using different tools and techniques. They are called the programme presentation tools and techniques. Popular tools and techniques used for programmes are flowchart and algorithm. Algorithm An algorithm is defined as a set of rules that state how a particular problem can be solved in a finite number of steps. In other words, an algorithm is a step by step representation of instructions to solve a problem. An algorithm must be composed of a finite set of steps, each of which may require one or more operations. A good algorithm should have the following features:- Input: specified and required input values Output: outcome values or solution of the problem Definite: clear definition of what should be done Effective: each step performed exactly in a finite amount of time Finite: have finite number of steps or operations Correct: must generate correct and desirable output Programming Tools and 15 Techniques Chapter
Oasis Radiant Computer Science, Book 7 200 Flowchart A flowchart is a pictorial representation of step by step solution of a problem. It is one of the oldest techniques to depict an algorithm and is an important tool in programming. A flowchart is independent of the programming language like the algorithm. A flowchart facilitates the computer programmer in the following ways: • Helps users understand the problem and steps more easily (even nonprogrammers understand) i.e. efficient means of communication. • Runs the process more effectively. • Helps correct the programme more readily and act as an analytical tool. The basic flowchart symbols are: Terminal Symbol Input / Output Symbol Processing Symbol Decision Symbol Connector Symbol Data Flow Line Start / End Input / Output Data Process Decision Connect