Computing - Compression

Why compression is needed

Why is compression needed?

Because data is constantly being moved around computer systems and networks so a smaller amount of data can be beneficial.

What are the two types of compression?

What’s an example of a lossy image compression format?

JPG

What’s an example of a lossy music compression format?

MP3

What is the definition of run length encoding?

A basic method of compression that summarises consecutive patterns of the same default.

When does RLE work best?

Image and sound data where data is repeated many times.

What is dictionary compression?

Where regularly occurring data is spotted and stored in a separate dictionary. Data is then replaced with a reference to the dictionary.

What is the overhead of dictionary compression?

The dictionary also has to be stored.