January 8th and 9th: Bitmaps and Compression

Learning Objectives

You will learn to:

Task 1:

The first task today is to ensure that you have notes in your yellow notebooks on Bitmaps and Compression.  We will look at the Teach-ICT.com resources:

http://www.teach-ict.com/gcse_computing/ocr/214_representing_data/bitmap/miniweb/index.htm


ENSURE THAT THESE NOTES ARE COMPLETE BY NEXT LESSON

EXTENSION AND HOMEWORK

1. Examine the files  A, B and C which can be found at:

Student shared/Subjects/Creative Technologies/GCSE Computing/Activity 1:1

2. Next complete the following questions:

Activity 1.1

Fill in this table to help you see what a difference compression makes to file size.
	File A	File B	File C
How many characters does the file contain?
What type of content does the file contain?
What is its file size before compression?
What is its file size after compression?
What is its compression ratio (decompressed size/compressed file size)?
Which file compresses the most? Explain why.