What is Compression Gain?
Posted on 2004-04-05
Can someone please tell me what is meant by compression gain.
I have compressed a text string with LZW, the efficiency before compression is 99.5% and after compression 92.3% using:
(Entropy / Av Codeword Length) * 100
It takes 50 bits to encode the data before compression and 60 bits after (so its not really worth compressing with this method).
So is the compression gain simply a bit value (ie 10 bits) or is it related to the efficiency (ie 99.5 - 92.3)
Thanks In Advance