Lecture 4 - Text Compression Intro Flashcards
1
Q
What is text compression?
A
A special case of data compression, done to save disk space and transmission time.
2
Q
What kind of a compression must text compression be?
A
Lossless, as we don’t want to lose words
3
Q
What does lossless mean?
A
Recoverable without errors
4
Q
What forms of media can afford to be lossy?
A
Pictures, videos, sounds
5
Q
What are the 2 approaches for text compression?
A
statistical and dictionary
6
Q
What is the compression ratio?
A
x/y, where x is the size of the compressed file and y is the size of the original file
7
Q
What is the percentage space saved?
A
(1 - compression ratio) * 100
8
Q
What is a typical percentage space saved?
A
40 - 60%
