Computing - Compression
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 comression?
- Lossy
- Lossless
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 occuring data is spotted and stored in a seperate 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.