Decompression software in the transfer of information

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Web Science[1]

Evaluation of lossy compression

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  • Significant reduction of file size –> important for file storage, transfer of data over the internet
  • E.g. image files can be reduced to be around 90% smaller before quality degradation is noticeable
  • Most important use is streaming multimedia files and VoIP –> bandwidth is usually limited
  • However, doesn’t work with all file types –> text files or binary data cannot be compressed in a lossy way, as the meaning of the data are lost
  • Different things to consider:
    • Compression speed
    • Decompression speed
    • Compression ratio

Evaluation of lossless Compression

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  • When compressing a file if decompressed will have the same data/Information as the initial file
  • Important when compressing an installation file and programs
  • It is required that the installation files and programs’ information is the same in the compressing and decompressing phase
  • No loss in quality in lossless compression in Images and Audio files
  • Larger file sizes than lossy compressions

Do you understand this?

From the IB: Students can test different compression methods to evaluateAssess the implications and limitations; make judgments about the ideas, works, solutions or methods in relation to selected criteria. their effectiveness.

Standards

These standards are used from the IB Computer Science Subject Guide[2]

  • EvaluateAssess the implications and limitations; make judgments about the ideas, works, solutions or methods in relation to selected criteria. the use of decompression software in the transfer of information.

References

  1. http://www.flaticon.com/
  2. IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.