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
103 = 1000
102 = 100
101 = 10
100 = 1 4 5 6 7

5. Binary (Base 2)
Now the categories we use to represent a number are powers of 2
26 = 64
25 = 32
24 = 16
23 = 8
22 = 4
21 = 2
20 = 1

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 1 26 64 25 32 24 16 23 8 22 4 21 2 20 1
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 11011026 64 25 32 24 16 23 8 22 4 21 2 20 1 1
Answer
= = 54

8. Practice Convert the binary number to decimal Answer 00011126 64 25 32 24 16 23 8 22 4 21 2 20 1 1
Answer
= = 7

9. Practice Convert the binary number to decimal Answer 010001126 64 25 32 24 16 23 8 22 4 21 2 20 1 1
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 25 or 32 so we put a 1 in that spot 26 64 25 32 24 16 23 8 22 4 21 2 20 1 1
37 – 32 =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 22 or 4 so we put a 1 in that spot 26 64 25 32 24 16 23 8 22 4 21 2 20 1 1
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 20 or 1 so we put a 1 in that spot 1 1 26 64 25 32 24 16 23 8 22 4 21 2 20 1
We then put zeros everywhere else

14. Example (37) And we now have represented 37 in binary 10010126 64 25 32 24 16 23 8 22 4 21 2 20 1
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 9 17 63 Answers26 64 25 32 24 16 23 8 22 4 21 2 20 1
Now write the following numbers in binary 9 17 63
Answers
9 = 1001
17 =
63 =

16. 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… 1 2 3 4 5 6 7 8 9 A B C D E F 10 11 12 13 14 15

17. Hexadecimal (Base 16)
Now the categories we use to represent a number are powers of 16
165 = 32
164 = 65536
163 = 4096
162 = 256
161 = 16
160 = 1

18. 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
165 = 32
164 = 65536
163 = 4096
162 = 256
161 = 16
160 = 1 1 2 3
Then we add up the numbers 1 (256), 2 (16) and 3 (1)
which means the number is = 291

19. 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
165 = 32
164 = 65536
163 = 4096
162 = 256
161 = 16
160 = 1 A B C
Then we add up the numbers 10 (256), 11 (16) and 12 (1)
which means the number is = 2748

20. 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)
165 = 32
164 = 65536
163 = 4096
162 = 256
161 = 16
160 = 1 B 8

21. 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 = …

22. 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

23. Color
Colors are made up of a certain percent of: Red, Green, and Blue. e.g.
We use binary numbers to represent different colors
Red
Green
Blue
Color
Black
255
White
Yellow
130
Pink

24. 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)

25. 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.

26. 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.

27. 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.

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