1. Binary Numbers

2. Remember we count using the decimal system or Base 10. That means there are 10 symbols: 0,1,2,3,4,5,6,7,8 and 9 Computers use the Binary or Base 2 system. They can only use 0 and 1 to represent numbers Recap

3. How do they do it? 168421 01101 Using the binary system we represent numbers in the following way. What number are we representing with this Binary code?

4. Using the cards on your desk can each group show me the binary code for the following decimal numbers. Your term to be a computer!

5. 19

6. 27

7. 6

8. 12

9. We can also go the other way. write down the decimal numbers that are represented by the following Binary codes. Pop Quiz!

10. 00110

11. 11010

12. 11100

13. 10101

14. 10011

15. How can we use binary to represent things other than numbers? How can we represent an image using Binary? How does a computer store an image when it can only use Binary numbers? What good is Binary?

16. A VERY Simple example

17. Run length compression

18. Example

19. How could we extend this idea so that we were also able to represent different colours? We can use another number to represent the colour of the run i.e. 1 = red, 2 = Blue, 3 = Yellow so 3,2 would be a run of 3 pixels each coloured blue What about colour?

20. Example

21. List 5 reasons in your book Why is compression important? -Files are smaller -Files run more smoothly -Saves time transferring or uploading files -Less chance of errors or glitches -Does not require a high spec, expensive machine

22. Copy out the Data Standards table from p148, provide the definition for each acronym and it’s use. Data Standards Type of dataStandardsDefinitionUsed for Images JPEG GIFGraphic Interchange FileAnimations for the web TIFF BMP Sound WAV MP3 AU