Computer Science

a compression method where data is permanently lost during the process

a compression method where no data is permanently lost during the process

how good, reliable or suitable something is for its intended purpose

Lossy and lossless compression

In this unit pupils will be introduced to the concept of data compression and why it is needed. The will compare lossy and lossless compression methods and their typical uses. They will have the opportunity to compression methods such as run length encoding (RLE) and Huffman coding.

Data compression

Put these image formats into size order (smallest to largest):

Why might lossy compression be used instead of lossless compression?

What is one advantage of lossless compression?

Yes, because data is permanently removed.

Yes, because it reduces the file size significantly.

No, it removes unnecessary data that may not affect perceived quality.

Does lossy compression always result in a poor-quality file?

Match each file type with the type of compression it commonly uses.

Which of the following is commonly compressed?

the maximum amount of data that can be transferred

the time delay between a signal being sent and received

What is one advantage of compressed files?

This lesson will be removed by end of Summer Term 2025.

Lossy and lossless compression

Lesson outcome

This lesson will be removed by end of Summer Term 2025.