Objectives:    Students will Identify methods for encoding images into binary and reproduce an image based on binary code.

 

• Inquiry question: How can computers store pictures when they can only use numbers?

• Stimulus resource = https://www.youtube.com/watch?v=0CYMC5b8KLE

• Computer screens are divided up into a grid of small dots called pixels (picture elements).  In a black and white picture, each pixel is either black or white. The letter “a” has been magnified above to show the pixels. When a computer stores apicture, all that it needs to store is which dots are black and which are white.

 

 

 

 

 

 

 

 

 

 

 

 

The picture above shows us how a picture can be represented by numbers. The first line consists of one white pixel, then three black, then one white. Thus the first line is represented as 1, 3, 1.  The first number always relates to the number of white pixels. If the first pixel is black the line will begin with a zero.

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Therefore the code for the letter "a" above is:

1, 3, 1

4, 1

1, 4

0, 1, 3, 1

0, 1, 3, 1

1, 4

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• Demonstration activity:  Activity 1

• Explanation video:  https://youtu.be/VsjpPs146d8

• Example video:  https://youtu.be/uaV2RuAJTjQ

• Activities:  Independent / pair work to complete  Activity 2.  Answer document to Activity 2 = Answers

 

Extension = Make your own picture and share it with a partner - Activity 3.

 

Differentiation:   Allow extra time for students.  Mixed groupings to collaborate understandings.  VAK strategies.

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Assessment:  Observations.  Completion of worksheets.

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Teacher resource:  http://www.bbc.co.uk/education/guides/zqyrq6f/revision

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