How does file compression work?

To make it simple, let’s take this famous quote:

“Ask not what your country can do for you -- ask what you can do for your country”. Notice that almost each word appears twice and that there 79 characters. When you compress a file, the computer takes the data that repeats and puts it in a “dictionary” and alphanumeric data. So the compressed phrase would be 1234567890—13607845, and the dictionary would be 1-ask, 2-not, 3-what, 4-your, and so on… until you run out of characters to add. That means the phrase after compression would be just only 19 characters!

What are the different types of file compression?

There are many software and types of file compression out there, but .rar compression with WinRAR has been known the be the best, along with .zip compression with 7Zip. The purpose of this experiment is to find out which compression software & format would have both quality and quantity.

Software

File Type

Windows Explorer (control)

.zip (control)

7Zip

.7z .zip

WinRAR

.zip .rar (normal) .rar (best compression)

.rar (fastest compression)

Lev

el o

f IV

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Software

File Type

Trial 1 Time

Trial 1 Size

Trial 1 Score

Trial 2 Time

Trial 2 Size

Trial 2 Score

Trial 3 Time

Trial 3 Size

Trial 3 Score

Average Score

Windows Explorer

.zip

28.4

44.7

73.1

28.5

44.7

73.0

FAILED!

73.05

7Zip

.7z

.zip

62.1 6.4

33.2 43.7

95.3 50.1

62 6.4

33.2 43.7

95.2 50.1

62 6.3

33.2 43.8

95.2 50.1

95.23 50.1

WinRAR

.rar (norm)

.rar (fast)

.rar (small)

.zip

30.1 20 30 6.9

41 42.3 40.7 44.4

71.1 60.3 70.7 51.3

30.1 20 30.1 6.7

41 42.3 40.7 44.4

71.1 60.3 70.8 51.3

30.1 20 30 6.7

41 42.3 40.7 44.3

71.1 60.3 70.7 51

71.1 60.3 70.7 51.2

Note: 100.1 mb of files were compressed! Remember that lower scores are better!

As I d

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com

pressed

file sizes are pre

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same acro

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bo

ard w

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time varie

s wid

ely.

During this experiment, I tested 7 different ways to compress some files. I learned how to actually go advanced into compressing a file and I also learned how to use the software.

My results from my experiment proved my hypothesis wrong… I had barely any experience with file compression prior to doing this experiment and the internet generally said using WinRAR with .rar compression would be the best. However the internet was wrong . It actually resulted in using 7Zip with .zip compression being the best! Within my results, I noticed that my trials for WinRAR were pretty much constant and the ending compression size were pretty much the same!

Problems that may have affected my experiment are probably inaccuracies in my screen capture software. I noticed that when I looked at the footage, some frames seemed to be “skipped”. Also, the points system may not have been the best way to find out the best way to compress a file…

Works Cited