Abstract: An apparatus and method for parallel decompression of compressed canonical Huffman encoded data.

Abstract: A method for coding "unconstrained" fixed codebook (FCB) excitation for ACELP speech coders is proposed. The unconstrained FCB does not place track-based constraint on the pulse positions. The coding method combines Huffman codes and combinatorial codes. The method is less sensitive to bit errors and is nearly as efficient as the combinatorial codes. A method for efficiently storing the parameters needed in the combinatorial codebook is also proposed.

Abstract: There are provided a Huffman decoding method and decoder which is capable of carrying out a decoding process at a high speed with a small memory capacity, and requires only a small-sized circuit. Input data encoded by a Huffman code is decoded. A Huffman decoding table is prepared which describes a binary tree corresponding to the Huffman code and having leaves each storing data. A binary tree-based search of the table is carried out based on the input data sequentially acquired by at least one bit to thereby decode the input data encoded by the Huffman code.

Abstract: Huffman coding ( 302 ) is first performed on uncompressed data ( 402 ) to obtain Huffman data ( 406 ). Additionally, the frequencies of one or more variable-length bit strings are also determined ( 408 ). At least one bit string is selected ( 304 ) when compression savings provided by the at least one bit string compares favorably with compression savings provided by the Huffman data. The Huffman data ( 406 ) is modified to account for the selection of the at least one bit string. Thereafter, compression is performed ( 306, 308 ) on the uncompressed data based on token replacements for the at least one bit string and, where necessary, on the modified Huffman data ( 420 ). In this manner, performance will be no worse than those techniques that employ Huffman coding. Using the present invention, greater compression efficiencies may be achieved without knowledge of the data being compressed while still preserving random accessibility of the data being compressed.

Abstract: A system and method for coding technique which achieves a high coding gain with simple, low-price implementation The system comprises a transmitter for transmitting encoded code words, and a receiver for receiving and decoding the code words, via a network In one embodiment, a low complexity modified R-S coding process is used to R-S encode smaller-bit words (eg, 7-bit words, instead of 8-bit words) In a second embodiment, a feed-back block concatenated coding process improves coding gain by utilizing concatenation and an erasure algorithm In a third embodiment, a feed-back block concatenated coding process is designed for an Ethernet The decoding processes utilize error-correcting capabilities built in during the three encoding processes described herein

Abstract: A new technique is proposed for decoding Huffman codes. In this technique a Condensed Huffman Table (CHT) for decoding purposes replaces a typical Huffman table. It is shown that a CHT is much smaller in size and the decoding becomes significantly faster. In an example with a typical Huffman table containing 108 codewords, it is shown that a CHT with only 14 codewords is sufficient to perform the decoding.

Abstract: Unique Huffman codes are generated with each being associated with a symbol. The unique codes are grouped according to a property of the unique codes such as length. The segments of a data stream to be decoded are compared with the grouped unique codes. Each segment has the same property as the grouped unique codes being compared with.

Abstract: The present invention provides a system that compresses and decompresses an image. The system includes a first codec a first stage codec for identifying runs of pixels of a defined value in a data stream of the image data beginning from the left and right margins of a line, such that information regarding the runs is assigned as a header and appended to the data stream. The compression device includes a second stage codec for scanning over remaining data in the data stream and compressing all but the header by utilizing a Huffman encoding scheme to reduce amount of data stored in the data stream, wherein the Huffman encoding scheme interleaves Huffman code values with unencrypted data while maintaining long word boundaries for the unencrypted data. The second codec also performs the operation of decompressing a compressed image.

Abstract: This paper summarizes the origin and the catalogue of data compression and analyses three kinds of data compression algorithms,which are Huffman coding,arithmetic coding,and LZ series algorithm.Their advantages and disadvantages are compared.At last,the concluding remarks on these algorithms are presented.

Abstract: Summary form only given. It is a well-known observation that when a DCT block is traversed in a zig-zag order, the AC coefficients generally decrease in size and the run-length of zero coefficients increase in number. Therefore, use of a single AC Huffman code table in the JPEG baseline algorithm leads to sub-optimal coding, and it is desirable to use multiple code tables, one for each DCT coefficient position, if necessary. It creates a problem, because a nonzero coefficient, X, and the run-length, Z, of zero coefficients that precede X, are coded as one element (Z,X), and therefore, the decoder may not know which table to use to decode the next X. To solve this problem, we made a minor modification to the JPEG Huffman coding algorithm. To evaluate reduction in the code size using our method, we compressed the luminancec component of ten well-known test images at default quality level and computed AC Huffman code size.

Abstract: Novel synchronous coding schemes are introduced and relationships between optimal synchronous codes and Huffman codes are also discussed. Although the problem of existence of optimal synchronous codes has not been resolved yet, we show that any synchronous code can consider as an optimal synchronous code for some information source and that there always exist optimal synchronous codes for the information source with a dyadic probability distribution. Comparing with Huffman coding, the synchronous coding is used not only for statistical modeling but also for dictionary methods. Moreover, it is proven that breaking a synchronous code is NP-complete.

Abstract: We have seen that Huffman coding has been widely used in data, image, and video compression. In this paper novel maximal prefix coding is introduced. Relationship between the Huffman coding and the optimal maximal prefix coding are discussed. We show that all Huffman coding schemes are optimal maximal prefix coding schemes and that conversely the optimal maximal prefix coding schemes need not be the Huffman coding schemes. Moreover, it is proven that, for any maximal prefix code C, there exists an information source I = (∑ P) such that C is exactly a Huffman code for I. Therefore, it is essential to show that the class of Huffman codes is coincident with one of the maximal prefix codes. A case study of data compression is also given. Comparing the Huffman coding, the maximal prefix coding is used not only for statistical modeling but also for dictionary methods. It is also good at applying to a large information retrieval system and improving its security.