1. Representing Nonnumeric Data
Everything is really a number

2. Its all 1’s and 0’s How do we represent other things?
Words/Pictures/Sound?

3. Text To store English we need Letters (upper case & lower) Punctuation
Special marks (space, newline, etc…)

4. Text To store English we need Assign each a number
Letters (upper case & lower)
Punctuation
Special marks (space, newline, etc…)
Assign each a number
ASCII encoding : most popular such scheme

5. ASCII table Partial table  Full Table: http://www.ascii-code.com/
DEC
OCT
HEX
BIN
Symbol 47
057 2F / 48
060 30 49
061 31 1 50
062 32 2 51
063 33 3 52
064 34 4 53
065 35 5 54
066 36 6 55
067 37 7 56
070 38 8 57
071 39 9 58
072 3A : 59
073 3B ; 60
074 3C
< 61
075 3D = 62
076 3E
> 63
077 3F ? 64
100 40 @ 65
101 41 A 66
102 42 B 67
103 43 C 68
104 44 D 69
105 45 E 70
106 46 F 71
107 G 72
110 H 73
111 I
Partial table 
Full Table:
A = 65 =
My name: A n d r e w

6. Text Why 0-127? Need more characters? Well it seemed like enough
127 is 2^7 – the biggest number you can write with 7 binary digits.
Need more characters?
Extended ASCII – 8 bits (1 byte) – 256 characters
Unicode – universal scheme – up to 4 bytes per character

7. Bitmaps
Image divided into pixels
Each pixel either on (1) or off (0)

8. Adding gray
2 digits for each square give 4 “colors” (00, 01, 10, 11)

9. Adding gray
2 digits for each square give 4 “colors” (00, 01, 10, 11)

10. Image Size Image is 2000 pixels wide & 1000 pixels tall.
2000 x 1000 = 2,000,000 pixels
Bits per Pixel 24 8 1
Number Colors
16,777,216
256 (color)
256 (grays) 2
Image Size
48,000,000 bits or ~5.7 MBytes
16,000,000 bits or ~1.9 MBytes
2,000,000 bits or ~244 KBytes

11. Vector Art Vector images are mathematically based
Everything described as lines and curves
Shapes are filled with solid color, gradients or patterns

12. Computer Sounds Two approaches to representing sound as numbers:
MIDI sequences
Samples