Lossless Compression
  • In Lossless Compression, the redundant information contained in the data is removed.
  • Due to the removal of such information, there is no loss of the data of interest. Hence it is called lossless compression.
  • Lossless compression is also known as Data Compaction.
  • Lossless compression techniques, as their name implies, involve no loss of information.
  • If the data has been losslessly compressed, the original data can be recovered exactly from the compressed data.
  • Lossless compression is generally used for applications that cannot tolerate any difference between original and reconstructed data.
  • Text compression is an important area for lossless compression.
  • The reconstruction must be identical to the original text, as very small differences can result in statements with very different meanings.

 

 

Lossy Compression
  • In this type of compression, there is a loss of information in a controlled manner.
  • The lossy compression is therefore not completely reversible.
  • But the advantage of this type is higher compression ratios than the lossless compression.
  • The lossless compression is used for digital data.
  • For many applications, lossy compression is preferred due to its higher conversion without a significant loss of important information.
  • For digital audio and video applications, we need a standard compression algorithm.
  • Lossy compression techniques involve some loss of information and data that has been compressed using lossy techniques generally can be recovered or reconstructed exactly.
  •  In return for accepting this distortion in the reconstruction, we can generally obtain much higher compression ratios than is possible with lossless compression.