Questions tagged [lz77]
LZ77 is a lossless data compression algorithm published by Abraham Lempel and Jacob Ziv in 1977.
lz77
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Is the DEFLATE compression algorithm in ZIP and GZip formats based on LZ77 or LZSS?
Wikipedia states that the DEFLATE algorithm (used among others by the ZIP and the GZip compression formats, but also by the PNG image format) is based on the LZ77 algorithm :
Deflate is a lossless ...
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Is it possible match initial bytes of Deflate compressed data using knowledge of first portion of uncompressed data?
So my obsession with deflate compression is leading me no where but i feel like there is something i can do the process better.
Here is what i understood so far:
def lz77(uncompressed):
#find ...
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LZ77 using the suffix tree
I have some problems understanding of how to effectively use the suffix tree in LZ77 with a sliding window, especially with deleting the suffix.
I seems that if I have the window of length m I need to ...
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Wrong encoding in LZ77
This function is somehow avoiding the ascii special characters such as space, new line sign or '\r', etc. It gives me wrong output basing on that implementation, implicating, that it is stricte ...
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Malformed PNG pixel data from deflate "unknown edge cases"
For the past 2 months, I've been implementing a png/deflate decoder, (for various reasons but mainly for learning purposes) but only returns the correct expected data in some cases.
Here in this table,...
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LZ77 and LZ78 differences in dictionaries
you can find in many sources this statement regarding LZ77 and LZ78.
They are both theoretically dictionary coders. LZ77 maintains a
sliding window during compression. This was equivalent to the
...
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How to use the "compressed binary" `C` arg for the compression type parameter of `^GF` in ZPL?
I'm trying to use this parameter with value C:
Here's a link to the manual page to read more:
https://support.zebra.com/cpws/docs/zpl/zpl_manual.pdf#page=210&zoom=auto,-20,721
Here's an xxd ...
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Big O time and space complexity of LZ77
What is the Time and space
complexities of the
LZ77 compression algorithm?
I'm trying to implement the algorithm with the best possible space and time complexity
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LZ77: storing format
I started to write a little program that allow to compress a single file using LZ77 compression algorithm. It works fine. Now I'm thinking how to store the data. In LZ77, compressed data consists in a ...
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decompress a doc file using LZS algorithm
https://github.com/sgherro/Exercises-cpp/blob/89bbd78eeac9666ed20f083ebf116e693a8c23ce/Lempel-Ziv-Stac/main.cpp
I am using this algorithm to decompress my doc file but it only decompress the partial ...
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LZ77 Extra Bits in DEFLATE
In the LZ77 phase of the DEFLATE compression, extra bits are used to represent the length and distances of the back reference. However, are these extra bits concatenated onto the base values to form a ...
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Could you give me some explain of LZ77 Algorithm?
I'm trying to learn LZ77 algorithm with my friend, and some case give us a confusion.
for example)
init
search buffer size: 7
look-ahead buffer size: 8
original string: abcabbcabbcabca
current
...
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How does DEFLATE optimize this so much?
I am trying to understand the deflate algorithm, and I have read up on Huffman codes as well as LZ77 compression. I was toying around with compression sizes of different strings, and I stumbled across ...
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How to extract the encoding dictionary from gzip archives
I am looking for a method whereby I can extract the encoding dictionary made by DEFLATE algorithm from a gzip archive.
I need the LZ77 made pointers from the whole archive which refer to patterns from ...
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How to design an efficient algorithm to support random access in LZ77 compressed sequences?
I'm working on a project in text compression and I need to design an efficient algorithm in a LZ77 compressed sequences. Specially, Given a LZ77 compressed sequence and an index i, we can
recover a ...
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