Methods and devices for source-coding and decoding of data involving symbol compression

Abstract

A method of encoding input data (D1) in an encoder to generate corresponding encoded data (E2) is provided. The method includes: (a) splitting and / or transforming the input data (D1) into one or more data chunks, and analyzing symbols present in the input data (D1) and compressing the symbols as a function of occurrence of the symbols in the one or more data chunks; (b) generating one or more code tables, and / or one or more frequency tables, and / or one or more length of code word tables for the symbols present in the one or more data chunks; (c) computing one or more sets of indices relating the symbols in each data chunk and / or the compressed symbols to entries in the one or more code tables, and / or the one or more frequency tables, and / or the one or more length of code word tables; and (d) assembling the one or more sets of indices, together with the one or more frequency tables, and / or the one or more code tables, and / or information indicative of such one or more tables, for generating the encoded data (E2). There is also provided an encoder (50) which utilizes the method, together with a corresponding decoder (60), wherein the encoder (50) and the decoder (60) in combination form a codec (100).

Description

technical field [0001] The present disclosure relates to methods of encoding input data to generate corresponding encoded data. In addition, the present disclosure also relates to a method of decoding the above-mentioned encoded data to generate corresponding decoded output data. Furthermore, the present disclosure also relates to encoders and decoders operable to implement the methods described above. Additionally, the present disclosure relates to a computer program product comprising a non-transitory computer readable storage medium having computer readable instructions stored thereon, wherein the computer readable instructions are executable by a computerized device comprising processing hardware for performing the method described above. Background technique [0002] In general, such as figure 1 As shown, a known encoding method for encoding input data D1 to generate corresponding encoded output data E2 involves applying one or more transformations T to the input data...

AI Technical Summary

Problems solved by technology

[0009] The main disadvantage of the simple method of pre-preparing the frequency counts associated with the symbols encoded into the compressed data output stream is that it actually increases the amount of data in the compressed data by at least several kilobytes (KB), so this simple method has minimal practical use

Optionally, the variable length codes themselves can also be written to the encoded output data, but since codes can have different sizes from each other, this may not be suitable in some cases

Alternatively, it is possible to write a Huffman tree to the encoded output data, but this requires more data to be transmitted than just the frequency of occurrences of symbols in a given data

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