1. Study Lecture 1: Block 3 part3 study session 1 Block 3 part3 study session 2 Block 3 part3 study session 3 Block 3 part3 study session 4 Block 3 part3 study session 5 Study Lecture 1: Block 3 part3 study session 1 Block 3 part3 study session 2 Block 3 part3 study session 3 Block 3 part3 study session 4 Block 3 part3 study session 5 Arab Open University Faculty of Computer Studies Computing and Information Technology Department T175 B: Networked living: Exploring Information and Communication technologies

2. What is a spreadsheet? How to enter data into a spreadsheet. Select and copy/paste cellsCreate a column chart 2 Spreadsheet basics

3. 2.1 What is a spreadsheet?  A program which allows you to enter, manipulate and display data, including numbers, text, dates and mathematical formulae. It is arranged in a set of columns and rows.  The rows are normally designated by a number and the columns by a letter.  See how can we specify a cell name, what is active or selected cell, how The active cell name appears in the "name box“, and what is formula bar next slide  2 Spreadsheet basics

5. You can usually have more than one sheet in a spreadsheet document (called a workbook in some packages). What is the name of the active workbook or sheet? in the picture below: (what is the name of the spreadsheet document?) 2 Spreadsheet basics

6. Spreadsheets software Examples: Microsoft Excel, StartOffice, SPSS, Visicalc, Lotus 1-2-3, Gnumeric. 2 Spreadsheet basics

7. o The csv format is used to transfer data between spreadsheets from different software products. o This is similar to the way the rtf format allows data to be transferred between word-processor programs from different software companies. o A csv file is a text file that separates every item of data by a comma 2 Spreadsheet basics

8. Can you tell the difference between the two software in the previous slide? Answer: No big difference. The general layout is the same only fine details of the tool bars differs. StarOffice has a toolbar on the left of the screen as well as at the top, however many spreadsheet packages allow you to ‘tailor’ the toolbars to your own requirements. 2 Spreadsheet basics

9. Spreadsheet history:  Spreadsheets were originally designed for applications in finance and accountancy -- in fact, the word ‘spreadsheet’ originally meant a particular ledger layout used for bookkeeping.  The first computer spreadsheets, introduced in the early 1980s, were designed for automating the sorts of calculation performed by accountants and bookkeepers.  Spreadsheets became so popular that they are often referred to as the software ‘killer application’ that helped popularize the PC.  People often talk about spreadsheets enabling you to answer ‘What if ?’ questions 2 Spreadsheet basics

10. 2.2 Creating a spreadsheet with a column chart Activity 3 1) Enter the data (information about the growth of the internet over the period from 1996 to 2002) 2) Select insert then column chart 3) Right click in series then select select data 4) Remove series1, click on series2 then select edit 5) In series name type “Millions of internet hosts”, then click OK 6) In Horizontal Category click edit, then select cells (from A2 to A8) 2 Spreadsheet basics

11. 7) Select Layout from the menu bar, then select Chart Title or Axis Titles to edit the titles of the chart. 8) At the end, you will have a chart similar to the following: 2 Spreadsheet basics

12. You can copy any objet (ex. Table, chart…) in excel or star office and paste it in a word document using copy and paste options: 2 Spreadsheet basics

13. 3.1 Using formulae  In cell A1 put the value 1, in cell A2 type: =A1+1, the ‘=‘ means that the program will treat the cell contents as a formula.  Formula bar shows  the formula ‘=A1+1’  Cell A2 shows  the result  Copy cell A2 paste it on cells A3 to A8  Note that the value in each cell = the value in the cell above+ 1 (depends on the cell position) 3 Spreadsheet activities for Parts 1 and 2

14. Answer A 1 bit word has two possible values (0 or 1) A 2 bit word has four possible values (00, 01, 11, 10) A 3 bit word has eight possible values (000, 011, ……) 3 Spreadsheet activities for Parts 1 and 2

15. The formula can be used in the cells B2 to B9 is: B2=B1*2 or, B2=2^A2 Now complete the table till a 16 bits word and then create a chart for this table 3 Spreadsheet activities for Parts 1 and 2

16. 3.2 Dealing with large ranges of numbers If you refer to the chart can you estimate the number of combination for the words of lengths from 1 to 6??? Is it zeros!!!! 3 Spreadsheet activities for Parts 1 and 2

17.  In order to cope with this situation, instead of a vertical (y) axis with linear scale (chart in the previous slide) a logarithmic scale is used.  Linear scale -> each increments corresponds to adding a certain amount (0, 5000, 10 000….) adding 5000 each time.  Logarithmic scale -> each increments corresponds to multiplying by a certain amount (1, 10,100…..) multiplying by 10 each time. 3 Spreadsheet activities for Parts 1 and 2

18.  To use different scale, double-click on the vertical axis, then check the ‘logarithmic’ box under the ‘Scale’ tab: Go to next slide to see the new chart 3 Spreadsheet activities for Parts 1 and 2

19. The chart will be as the following (using logarithmic scale) Now can you give an approximate value for the number of combinations for the word lengths from 1 to 6, using logarithmic scale we can see more details of the smaller word lengths 3 Spreadsheet activities for Parts 1 and 2

20.  In this example, the values increases in a very particular way it doubles for each increase in word length of 1 bit. Growth like this is called exponential.  Any growth where the value increases by a given factor with respect to something else is exponential.  For example, compound interest on a savings account is an example of exponential growth with respect to time. The term is often misused, however. You will hear people refer to any rapid growth as ‘exponential’.  Plotting data using a logarithmic scale offers a rough-and-ready way of checking whether growth really is exponential -- if it is, the column heights will form a straight line 3 Spreadsheet activities for Parts 1 and 2

21. Activity 9 (self-assessment) The area of a square is given by the length of a side multiplied by itself Is this type of growth exponential?? See the figure next slide a Area= a*a=a^2 3 Spreadsheet activities for Parts 1 and 2

22.  The growth is slower than exponential, since the increment in column heights gets less as the square size increases (Page 28) 3 Spreadsheet activities for Parts 1 and 2

23. 3.3 The grapevine Activity 11 (exploratory) How fast the news can travel, if you tell a story to a couple of people who each tell it to two or three more people. 1) Can you represent the situation in a table? 2) What will be the formula used to produce each generation ? 3) Is this type of growth exponential? How can you answers this question? 3 Spreadsheet activities for Parts 1 and 2

25. 3.4 The price of flash memory Activity 12 (exploratory) Assume that each year the cost of flash memory is a quarter of what it was the year before, and this rate of cost reduction remains steady over the period. 1) Can you represent the situation in a table? 2) What will be the formula used to produce each generation ? 3) Is this type of growth exponential? How can you answers this question? 3 Spreadsheet activities for Parts 1 and 2

26. Note: In order to select how many decimals in a number, you highlight the cells you want to change, right click, select cell format, then select the ‘Number’ tab. Numbers with4 decimal places and 1 leading zero (i.e. a single zero before the decimal place) 3 Spreadsheet activities for Parts 1 and 2

27. The chart will look like this: To let the x-axis start from 0.0001 change the value as shown in the following figure 3 Spreadsheet activities for Parts 1 and 2

28. Note: Notice how the plot on a log scale is again linear, but that it is falling. This is an example of exponential decay. Just as multiplying repeatedly by a given factor results in exponential growth, so dividing repeatedly by a factor (dividing by 4 each year in this case) causes exponential decay. 3 Spreadsheet activities for Parts 1 and 2

29. Moore’s Law: Although it seems to be improbable that the price will continue falling in this way, the exponential growth of memory size and computing power per unit cost was remarkable over the last few decades this is known as Moore's Law. 3 Spreadsheet activities for Parts 1 and 2

30.  Using a new graphics editing package (IrfanView)  Picture representation.(pixels)  File sizes and data compression 4 Graphics

31. You can install from the DVD with the T175 Guide IrfanView is a graphics editing package From the File drop down menu select open then for instance to open a preinstalled image called Mellor follow this path C:\T175\Block_3_Images\Mellor.bmp How can I open a file? Click on the icon form the irfanView tool bar now you can check all image properties as shown in the next slide How can I see image properties? 4 Graphics

32. The original size before resizing. Tell you the maximum number of colors you can have when you use 8 bits per pixel. Number of pixels here it is just over 2 million(2.05 Mpixels). different than the original size because you can resize the picture 150 dots per inch both horizontally & vertically. Dot here means pixel. Tell you the maximum number of colors you can have when you use 8 bits per pixel. How many colors there are rather than how many there could be. Here the used color are 256 refers to the size of this file on your hard drive refers to the amount of space taken by this picture in your computer’s RAM

33. 4.2 Greyscale Activity 13 (exploratory) use IrfanView to compare the data of the two pictures (Reddish Vale.bmp and Mellor.bmp). You should have found that the data for Reddish Vale.bmp was very similar to that of Mellor.bmp, except in one respect. In ReddishVale.bmp the number of unique colours is 2, whereas in Mellor.bmp it is 256. 4 Graphics

34. ‘monochrome’, which literally means ‘one colour’. ‘greyscale’, meaning that they consist only of shades of grey. Here 8 bits per pixel are used to represent ‘colour’. 8 bits correspond to 256 different values (256 = 2^8) ‘colour’ is any one of those 256 different numbers. For example, binary number 0000 0001 is one colour. 256 is the maximum number of colours, the picture might have fewer. 4 Graphics Screenshot of Mellor.bmp properties

35. 1 bpp, 2 1 = 2 colors (monochrome) 2 bpp, 2 2 = 4 colors 3 bpp, 2 3 = 8 colors 4 bpp, 2 4 = 16 colors 5 bpp, 2 5 = 32 colors 6 bpp, 2 6 = 64 colors 7 bpp, 2 7 = 128 colors 8 bpp, 2 8 = 256 colors 4 Graphics

36. Size In this example number of colours ia 256  2^8. Which means 8 bits to represent 1 pixel. Which means also 1 byte to represent 1 pixel. 2051318 bytes is used to represent 2051318 pixels. 2051318 bytes/1024 bytes = 2003.24 KB 2003.24 KB/1024bytes = 1.96 MB Disk size  Compressed size Current memory size  decompressed size. 4 Graphics Screenshot of Mellor.bmp properties

37. No compression  disk size= Current memory size Else  disk size< Current memory size, because loading a compressed file (ex. Jpeg) into RAM involve decompression 4 Graphics

38. 4.3 Reducing the file size Activity 14 (self-assessment) (a) What is the smallest number of bits per pixel that can be used in Reddish Vale.bmp without affecting the appearance of the picture? (b) What will be the effect of using that number of bits per pixel on the file size? Answer (a) One bit per pixel will be enough. This is because we need to represent only two colours: black or white. We could use 0 to represent black and 1 to represent white. (b) The file size will be reduced considerably if we use 1 bit per pixel. There will still be about 2 million pixels, but each one will be represented by 1 bit rather than 8 bits. We can expect the file size to shrink to one-eighth of its former value. 4 Graphics

39. Activity 15 (exploratory) 1. Open Reddish Vale.bmp in IrfanView. 2. Go to Image, then select decrease color depth. 3. Reduce color depth for Reddish Vale.bmp to 2. 4. Check image properties. 5. The current size is less than the disk size by a factor of 8. this is without saving. Do the same for Mellor.bmp, what would be the result!! (bring your solution next meeting) 4 Graphics

40. Colour depth is the term used to represent the maximum number of possible colours in a digital image. We can express colour depth either as a number of levels or as a number of bits per pixel. So, for instance we would speak of a colour depth as 256 colours, or as 8 bits per pixel (or just ‘8 bits’). 4 Graphics

42. Do lossless compression for Reddish Vale.bmp and Mellor.bmp images: Activity 20 (exploratory) 1. Open Reddish Vale.bmp in IrfanView. 2. Save the image as a TIF (tagged image file) with LZW compression in any folder. 3. Reopen the saved image, and then check the image properties. 4. The disk size is less than the current size(RAM). Because the disk size is the compressed size, RAM is the uncompressed size. Do the same for Mellor.bmp, what would be the result!! (bring your solution next meeting) 4 Graphics

43. Do lossy compression for Reddish Vale.bmp and Mellor.bmp images: 1. Open Reddish Vale.bmp in IrfanView. 2. Select image type JPG – JPEG, then set the ‘Save quality’ slider to about 30. 3. Save the image in any folder. 4. Reopen the saved image, and then check the image properties. 5. The disk size (345 KB) is less than the current memory size (5.8 MB). Do the same for Mellor.bmp, what would be the result!! (bring your solution next meeting) 4 Graphics

44. Now you would be able to complete the following table: After completing the table you will notice the following: 1. Disk size of Mellor image with lossless compression is larger than the disk size of Mellor before compression, why? 2. Lossless compression is more effective when used in Reddish Vale image than lossy, why? 3. Memory size of Mellor image after lossy compression is larger than before compression, why? (bring your answers next meeting..) 4 Graphics picture Compression typeOriginal (BMP)Lossy (jpg-jpeg)Lossless (LZW) Mellor Current memory size1.96 MB Disk size1.96 MB Reddish Vale Current memory size1.96 MB Disk size1.96 MB

45.  The JPEG standard is defined in terms of a colour depth of 24 bits per pixel.  in JPEG there are 2 steps : 1) lossy (reduce the variation, sacrifice subtle variations of colour in order to reduce file size. ) 2) lossless (representation using any lossless method)  Images with few colors – hence a lot of repeating patterns  lossless is more effective. Else  lossy is more effective. 4 Graphics

46. 4.5 From grey to colour  The colour of a pixel on a display comes from combining three primary colours: red, green and blue.  A computer display has millions of tiny emitters of primary-coloured light: some emit red, some emit blue and some emit green.  Clusters of these emitters are grouped into pixels.  The overall colour of the pixel is varied by adjusting voltages applied to the primary emitters within the pixel.  When you first open an image without zooming in or out, each pixel of the picture is displayed using one pixel on your screen.  If you zoom in or out, the relationship between pixels in the picture and pixels in the monitor changes. 4 Graphics

47.  In a bitmap file, such as a BMP file or a TIF file, an 8-bit number is typically used to indicate the ‘brightness’ of a primary colour in a pixel.  Because there are three primary colours, three 8-bit numbers are needed to specify all three primaries of a pixel.  This means a 24-bit number is needed to represent the ‘colour’ of the pixel. 4 Graphics Brightness of the red colour Brightness of the green colour Brightness of the blue colour Binary11001000 Denary200

48.  Turning all three primaries off, by giving them a value of 0, 0, 0, produces black.  When all three primaries have maximum values of 255, 255, 255, the result is white. (see figure below, using MS Paint program)  What would be the colour presented by adjusting the values by 200, 200, 200? (bring your answer next meeting). 4 Graphics

49. 4.6 Other formats  Two of the most widely used of formats are GIF and PNG. Both of these are intended primarily for use with Web graphics (for instance, on websites) and uses lossless compression.  The GIF format incorporates LZW lossless compression. It also restricts files to a colour depth of 256 colours (8 bits per pixel). Thus, if you start with a file with more than 256 colours and save it as a GIF, it will have only 256 colours after you have saved it.  The PNG format (Portable Network Graphics) incorporates lossless compression, but is not restricted to 256 colours. 4 Graphics

50.  With 24 bits per pixel we can have 256 different red values, 256 different green values and 256 different blue values. This means that the total number of colours that can be displayed by a pixel is: 256 x 256 x 256 = 16 777 216  True colour monitor: the monitor that can display this number of colours. 4 Graphics

51.  Today, computer generated imagery (CGI, ex. Maya program ) is used extensively to provide virtual sets, animated scenes and characters in movies  watch the movie Computers and animation (you can find this on your course DVD) then summarize the 6 sections of the movie then draw a suitable spray diagram summarizing what have been learned: ( please post your answers to our course forum) 4 Graphics