Computer Science

the file size before any compression has been applied

a comparison of the original file size to the compressed file size

the file size after compression has been applied

Compression ratios

Measurements of storage

The need for compression

Lossy and lossless compression

Run length encoding

Huffman coding

Comparing compression algorithms

Practical applications of 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

What is a potential downside of a higher compression ratio?

Which factors should be considered when choosing a compression algorithm?

What happens to a file size with a higher compression ratio?

a comparison of original and compressed sizes

time taken for compression or decompression

Yes, because it improves the resolution of the file.

No, it means the file size has been reduced more, often lowering quality.

Yes, because it makes files easier to process.

Does a higher compression ratio always mean better quality?

What is the main characteristic of lossy data compression?

It reduces file size without losing data.

Which of the following is true about lossless compression?

What is the effect of lossy compression on quality?

How does lossy compression affect file size?

What type of compression does the JPEG format use?

What type of compression does the PNG format use?

Compression ratios

Lesson outcome