LZW dictionary search method based on character string parallel search

Abstract

The invention discloses an LZW dictionary search method based on character string parallel search, belongs to the field of communication, and can effectively reduce the dictionary search frequency while ensuring the same compression rate, thereby realizing the balance between compression delay and complexity. The method comprises the following steps: taking N character strings in a current character string sequence as a parallel search group, wherein each character string comprises a prefix character and a suffix character, and the current parallel search group comprises N character strings; performing search matching in the LZW dictionary by utilizing the current parallel search group to obtain a group matching result; in the group matching result, taking every '1' interval and taking every '0' sequence; taking an address every '1', taking a prefix every '0' to obtain code values, and outputting all the code values in sequence as an LZW dictionary search result of the current parallelsearch group. in the current character string sequence, combining the LZW dictionary search results of all the parallel search groups into an LZW dictionary search result of the current character string sequence.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to an LZW dictionary search method based on character string parallel search. Background technique [0002] The LZW dictionary encoding method establishes a dictionary according to the input character sequence, and replaces the original characters with the index value of the dictionary to achieve the purpose of data compression. In the compression process, the dictionary index value is used to replace the input string sequence, and the strings that have not appeared are dynamically added to the dictionary; in the decompression process, search and match are performed in the dictionary according to the input compression codeword, and Output the corresponding string according to the matching result, and update the dictionary at the same time. It can be seen that the compression and decompression process of the LZW encoding method needs to dynamically build and search the dictio...

AI Technical Summary

Problems solved by technology

The sequential search method searches serially according to the order of dictionary addresses from small to large until a matching dictionary entry is found. This method is simple and easy to implement, but the search delay is very large

The parallel search method first divides the dictionary into multiple small dictionaries, and then searches the small dictionaries in parallel. This algorithm effectively reduces the search delay, but each small dictionary needs to be updated, resulting in complex control logic

The hash table search finds the storage position of the input character in the dictionary according to the mapping function, which can reduce the search delay, but the hash table search has the problem of address conflict

[0005] The above existing dictionary search methods still have the problem of unbalanced compression delay and complexity. Therefore, there is an urgent need for a LZW dictionary search method that can balance compression delay and complexity.

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