Decompression software in the transfer of information: Difference between revisions

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== Evaluation of lossy compression ==  
== Evaluation of lossy compression ==  
 
Credit to [https://www.cs-ib.net/sections/C-03-distributed-approaches-to-the-web.html these guys for this material!]
* Significant reduction of file size –> important for file storage, transfer of data over the internet
* 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
* E.g. image files can be reduced to be around 90% smaller before quality degradation is noticeable
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** Decompression speed
** Decompression speed
** Compression ratio
** Compression ratio


== Evaluation of lossless Compression ==
== Evaluation of lossless Compression ==

Revision as of 15:57, 12 January 2018

Web Science[1]

Evaluation of lossy compression[edit]

Credit to these guys for this material!

  • 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[edit]

  • 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?[edit]

From the IB: Students can test different compression methods to evaluate their effectiveness.

Standards[edit]

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

  • Evaluate the use of decompression software in the transfer of information.

References[edit]

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