Compression Flashcards
What is compression?
Compression is the process of making a file size smaller. This may be advantageous as it allows more data to be stored on the disk, and files may also be transferred more quickly. There are two primary methods that are used to compress files stored on a computer system; these are lossy and lossless.
Advantages and disadvantages of compression
This may be advantageous as it allows more data to be stored on the disk, and files may also be transferred more quickly.
How to compress?
There are two methods of achieving disk compression; one is software based and the other hardware based.
Software based disk compression is often included as a facility of an operating system and so it is readily available on most computer systems. The disadvantage of this is that it slows down the process of reading and writing to disk.
Hardware disk compression requires specialist hardware, which can be expensive. However, it does not affect the speed of access as much as software based disk compression.
What is lossless compression?
Lossless compression uses an algorithm that compresses data into a form that may be decompressed at a later time without any loss of data, returning the file to its exact original form. It is preferred to lossy compression, when the loss of any detail, for example in a computer program or a word-processed document, could have a detrimental effect.
What is lossy compression?
Lossy compression is a technique that compresses the file size by discarding some of the data. The technique aims to reduce the amount of data that needs to be stored.
