Today the class carried out an investigation into the JPEG image compression technique.  The pupils were tasked with finding out.

• Why we use JPEG compression on images?
• How does JPEG compression work?
• What is JPEG good at?
• What is JPEG bad at?
• When would we use JPEG compression?

The Pupils had to report on a powerpoint slide and include an example of a good and bad use of JPEG.

Why?

We use JPEG to make an image file size smaller. This helps to store more files on a device and also allows us to send it quicker on a network.

How?

JPEG works by removing the parts of the image that the human eye would have difficulty seeing (lossy compression).

Good at?

Photographs and complicated images using lots of colours.

Bad at?

Line art or images of written text. (see image for examples of JPEG artefacts)

When would we use it?

We would use it any time we want to have a photographic type image with a very small file size.