How is Information Stored

Transcription

1 Binary CSCE 101

2 How is Information Stored Information is stored in the computer as binary numbers (0 s and 1 s). Even images are stored in this way, where a combination of 0 s and 1 s represent each color in the picture Each binary number is a switch where 0 is off and 1 is on How to read/write binary:

3 Base 10 The system we generally talk about numbers is in a 10 based system, also called decimal In 10 based system we talk about how many 1 s we have, how many 10 s, how many 100 s etc For example the following number 4567 is 7 ones 6 tens 5 hundreds 4 thousands

4 Base 10 Each of the categories, ones, tens, hundreds, thousands, are different powers of 10

5 Binary (Base 2) Now the categories we use to represent a number are powers of 2

6 Binary (Base 2) What is the number 1101 in the two based system? First we put the number in the chart, aligning it to the right Then we add up the numbers 1 (8), 1 (4) and 1 (1) which means the number is = 13

7 Practice Convert the binary number to decimal Answer = = 54

8 Practice Convert the binary number to decimal Answer = = 7

9 Practice Convert the binary number to decimal Answer = = 35

10 Writing numbers in binary You follow the same process as when you write a number in decimal format. First find the highest power of two that goes into the number Subtract that amount from the number, Put a 1 in that spot and repeat

11 Example (37) Write 37 in binary First we see that the largest power of 2 that goes into the number is 2 5 or 32 so we put a 1 in that spot =5 Now we need to add 5 to this number

12 Example (37) Now we need to add 5 to our number We see that the largest power of 2 that goes into the number is 2 2 or 4 so we put a 1 in that spot 5 4 =1 Now we need to add 1 to this number

13 Example (37) Now we need to add 1 to our number We see that the largest power of 2 that goes into the number is 2 0 or 1 so we put a 1 in that spot We then put zeros everywhere else

14 Example (37) And we now have represented 37 in binary We can add as many 0 s to the left of the numbers as we like and it stays the same. So this number is the same as

15 Practice Now write the following numbers in binary Answers 9 = = =

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18 Practice Convert 3567 to binary?

19 Practice Convert 3567 to binary? Ans :

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28 Hexadecimal (Base 16) Now the categories we use to represent a number are powers of 16 Since, our numbers go higher then 10 we need more characters. Our numbers are now

29 Hexadecimal (Base 16) Now the categories we use to represent a number are powers of 16

30 Hexadecimal (Base 16) What is the number 123 in the 16 based system? First we put the number in the chart, aligning it to the right Then we add up the numbers 1 (256), 2 (16) and 3 (1) which means the number is = 291

31 Hexadecimal (Base 16) Let s try ABC in the 16 based system? First we put the number in the chart, aligning it to the right Then we add up the numbers 10 (256), 11 (16) and 12 (1) which means the number is = 2748

32 Hexadecimal (Base 16) Let s try taking a decimal number and converting it to Hexadecimal. Let s convert the number We do this by repeatedly dividing by 16, the remainder goes on the farthest right column. 3000/16 = 187 R 8 (Put 8 in farthest right) 187/16 =11 R 11 (But B in next right) 11/16 = 0 R 11 (Put B in next right)

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43 1. a. b. c. d.

44 ASCII Stands for American Standard Code for Information Interchange The way we represent English characters as numbers (binary) Each letter is assigned a number form 0 to 1 A = B = C =

45 Text Compression Can take body of text and make it smaller Makes it more feasible for you to send these files Will find simplify repeated patterns so they take up less space. the rain in Spain falls mainly on the plain. becomes? r! in Sp! falls m!ly on? pl!.! = ain? = the

46 Color Colors are made up of a certain percent of: Red, Green, and Blue. e.g. We use binary numbers to represent different colors

47 Images Each pixel of color in an image is represented by a binary number The more pixels in an image the less pixelated the image looks, the higher the resolution, and the more space it takes up (The extra pixel data needs to be stored)

48 Image Compression In a vector image there is a lot of repeated color. Hence the compression can be very effective, and you can use lossless compression.

49 JPG JPG Images is a compressed file format, making it take up less space on your website and become faster to load The compression is lossy. This means that some of the image data is actually lost; however, the change in quality is said to be invisible to the human eye. JPG compression works well for pictures JPG does not work well for lettering or simple images of few colors.

50 GIF GIF uses a losless compression. Only supports 256 colors GIF is better than JPG for images that have few colors. Simple images. Images like sunsets have tons of colors, even though they are close in shade and should use JPG rather than GIF.

51 PNG An improvement on GIF Can be compressed slightly more, and supports more transparency.

52 Calculating image size 1) Black n white or grayscale or monochrome a) Image Size = 640 x 480 b) Total pixels = 640 x 480 c) 1 pixels = 8 bits d) Total bits = 640 x 480 x 8 2) Color Images a) 3 colors - RGB b) Monochrome * 3