What is data compression?

Data compression is a reduction in the number of BIT needed to represent data.

Compressing data can save storage capacity, speed up file transfer, and decrease costs for storage hardware and network bandwidth.

Data compression methods

Compressing data can be a lossless or lossy process. Lossless compression enables the restoration of a file to its original state, without the loss of a single bit of data, when the file is uncompressed. Lossless compression is the typical approach with executables, as well as text and spreadsheet files, where the loss of words or numbers would change the information.

Lossy compression permanently eliminates bits of data that are redundant, unimportant or imperceptible. Lossy compression is useful with graphics, audio, video and images, where the removal of some data bits has little or no discernible effect on the representation of the content.

Example data compression LossLess

 

IMS gives the compression exit routine control whenever a segment that requires compression or expansion is accessed. As shown in the following figure, the phrase “this is data” is compressed from 12 bytes down to 5 bytes.

Example data compression Lossy

Lossy compression permanently eliminates bits of data that are redundant, unimportant or imperceptible you still recognition

Pros and cons of compression

Pros

  • Reduction in storage hardware
  • Data transmission time
  • Communication bandwidth

=> Resulting cost savings

Cons

  • Impact resulting from the use of CPU and Memory
  • Added complexity
  • Effect of errors in transmission