Compression of random binary data
danceswithnumbers at gmail.com
danceswithnumbers at gmail.com
Thu Oct 26 16:38:09 EDT 2017
Thomas Jollans
On 2017-10-25 23:22, danceswi... at gmail.com wrote:
> With every transform the entropy changes,
That's only true if the "transform" loses or adds information.
If it loses information, that's lossy compression, which is only useful
in very specific (but also extremely common) circumstances.
If it adds information, that's poetry, not compression.
Not true! You can transform a stream lossless, and change its entropy without adding to or taking away. These two streams 16 bits are the same but one is reversed.
1111000010101011
This equals
61611
This can be represented using
0-6 log2(7)*5= 14.0367746103 bits
1101010100001111
This equals
54543
This can be represented using
0-5 log2(6)*5= 12.9248125036 bits
In reality you can express 54543 with 10 bits.
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