This document discusses file compression. It defines file compression as a data compression method that reduces the original size of a file to save disk space and enable faster transmission. File compression can impact data transfer speed, security, server disk space, energy conservation and server requirements on the internet. Compression is classified as either lossy or lossless, where lossy reduces bits by removing unnecessary information and lossless reduces bits by eliminating redundancy. The document outlines the file compression process and how to calculate compression ratios. It notes the advantages of compressed files taking up less space and allowing more efficient transfers, while the disadvantage is the time required for compression.

1. File Compression

2. Group Members
Samiha Tahsin
2015-2-50-008
Jannatun Nayeem
2015-2-50-013
Taslima Yasmin
2015-2-50-022

3. What is File Compression?
A data compression method
Reduce original size of file
Save disk space
Easier & faster transmission

4. File Compression Impacts on Internet
Data Transfer
Speed
Data Security
Server Disk
Space
Energy
Conservation
Server
Requirements

5. Classification of Compression
• reduces bits by
detect the
unnecessary
information and
removing it
Lossy
Compression
• reduces bits by
identifying and
eliminating redundancy
Lossless
Compression

6. Overview After Compression

7. Creationg Process of Compress File

8. How Does Compression File Works :
Letters & character along with the frequency
in the message
Pairs to be nodes as leaf nodes and pick the
two nodes with the lowest frequency
Make a new node out of these two
Node is the sum of the frequencies
Continue till the time only one node left.

9. Creationg Process of Compress File

10. Creationg Process of Compress File

11. Compression Ratio Calculation
.
• 10 MB file to 2 MB compression ratio is 10/2 =
5/1 , 5:1
,
• 10MB file to 2MB space savings of 1 - 2/10 =0.8,
percentage 80%

12. Ratio Between the Original Size &
Compressed Size
F.S-59460
C.S-20952
Ratio-65%
F.S-39173
C.S- 36507
Ratio-7%
F.S-
1131654
C.S-7417
Ratio-99%
F.S-
1131654
C.S-33225
Ratio-97%

13. Ratio Between the Original Size &
Compressed Size
 The highest
compression ratio
is almost always
lossy compression
 The lowest
compression ratio
is almost always
lossless
compression

14. Advantages of Compressed File
Take less space
• unplanned files zip
• Storing of movies
More efficient transfer
• Emailing a large file
• Recipient extract the files buy WinZip
Can save money
• Buy a expensive hard drive
• 200GB after ZIP file 100GB

15. Disadvantages of Compressed File
Compress action takes time
Uses extra memory to run the sub-files

16. “Compression optimizes backup storage
performance
Compression will be an important method of
data reduction as data continues to grow
exponentially”

17. THANKS!

18. Any Question