Questions tagged [lempel-ziv-76]
10 questions
3
votes
4 answers
What is the POSIX System Library for the LZW Algorithm Used by the Compress Utility
This has been an incredibly difficult question to Google. I am not looking for gzip or Zip or deflate. The algorithm I want to use is called "compress" but that does not mean I am trying to implement compression in general. I am looking for a…
William Rosenbloom
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2
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2 answers
Can ziv lempel efficiency be improved by compressing longer repetitions
I have a question - I was introduced to a version of Ziv- Lempel that encodes only repetitions of size 3 or longer(repetitions of 1 or 2 characters aren't encoded - the characters themselves are placed to the coded string and not the (m,k) value). I…
user3167141
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2 answers
Can I create a .Z file with gzip?
I need to create a .Z (compress) file as the receiver is expecting to read it with uncompress utility. But I don't have the possibility to install compress package on my Linux host.
Is there a way to get the compressed .Z file (using adaptive…
Stefano Radaelli
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vote
0 answers
LZ78 implementation
A quick but sufficient definition of LZ78 is the one from Wikipedia:
Each dictionary entry is of the form dictionary[...] = {index,
character}, where index is the index to a previous dictionary entry,
and character is appended to the string…
Jean-Baptiste Yunès
- 34,548
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1
vote
1 answer
Entropy Estimator based on the Lempel-Ziv algorithm using Python
This function allows to estimate the entropy of a time series. It is based on the Lempel-Ziv compression algorithm. For a time series of length n, the entropy is estimate as:
E= (1/n SUM_i L_i )^-1 ln(n)
where L_i is the longness of the shortest…
Zhicong Chen
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0
votes
0 answers
Problem in Reading/Writing Files in Python
I have an assignment where I have to apply the Lempel-Ziv Algorithm (Python). I have to read an input file build a program that compresses it and generates the compressed file, and then build another program that decompresses the compressed file…
Pedro Leite
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Problem with decomressing multiple equal symbols with Lempel-Ziv
Working on a lempel-ziv decompression method, and we're having some trouble. Text lines like below won't decomress correcctly.
----------+----+----+----+----+----+----+----+----
It becomes like below and makes a mess of the next…
Kristina
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UTF-16 string compression implementation
C language/compression algorithm noob here, apologies in advance.
I am looking into a utf-16 string compression algorithm based on Lempel-Ziv as explained here http://www.unicode.org/notes/tn31/
According to the implementation…
user3689913
- 382
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0
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2 answers
Lempel-Ziv 76 complexity
Can someone explain to me Lempel-Ziv 76 complexity? I was under the impression that you initialize with the first letter of the string in your dictionary, and then check subsequent blocks for existence in the previous substring, growing one letter…
aznpwnzor
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-2
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1 answer
IndexError: list assignment index out of range python 3.4
In lempel-ziv decode methode I get indexError
this is my code, I know that size will be 3, while len(LT) is just 2.
But I just converted the pseudocode to the python code .
def decode(self,target):
tlen = len(target)
source = ''
…
AJProg
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