Data Representation - Images

Lesson Objectives

To remember that computers interpret only zeros and ones (binary)

To understand how an image is represented by pixels(picture elements) in binary format

To recognise why metadata needs to be included in an image file(height, width, colour depth)

Starter

How are images represented on the computer?

Main

Red Task

Download and complete the Bitmap Images file HERE


Orange Task

 

TASK - on squared paper

Green Task
Do some research on Lossy and Lossless compression.

Find an image and open in a graphics package of your choice. 
Save a version of the file in a Lossy format and a second copy in a Lossless format.

Look at the file size and image quality. 
What do you notice?

Use fileinfo.com to investigate other file formats

Extension
Images in Computing TEST

Further Reading

http://www.bbc.co.uk/education/guides/zqyrq6f/revision/1
http://www.aifweb.com/2d_graphics/resolution.html
http://www.teach-ict.com/gcse_computing/ocr/214_representing_data/bitmap/miniweb/index.htm
http://www.yourhtmlsource.com/images/fileformats.html
http://www.scantips.com/basics1d.html

Plenary

Add a post to your Blog about how images are are stored on the computing.

Try to include as many of the following key words as you can:

Bitmap

Pixel

File Size

Resolution

Metadata

Compression

Lossy

Lossless