To reduce the amount of data lossless processes can be used. These methods make use exclusively of the redundancy of the data.
Processes with this principle are called entropy encoding. There are several of this kind. Entropy encoding is used regardless of the media’s specific characteristics. The data stream to be compressed is
considered to be a simple digital sequence, and the semantic of the data is ignored. Entropy encoding is an example of lossless encoding as the decompression process regenerates the data completely. The
raw data and the decompressed data are identical, no information is lost.