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Efficient and Compact Representations of Some Non-canonical Prefix-Free Codes [chapter]

Antonio Fariña, Travis Gagie, Giovanni Manzini, Gonzalo Navarro, Alberto Ordóñez
2016 Lecture Notes in Computer Science  
For many kinds of prefix-free codes there are efficient and compact alternatives to the traditional tree-based representation.  ...  We also consider a kind of optimal prefix-free code introduced recently where the codewords' lengths are non-decreasing if arranged in lexicographic order of their reverses.  ...  It started at a StringMasters workshop at the Research Center on Information and Communication Technologies (CITIC) of the university. The workshop was  ... 
doi:10.1007/978-3-319-46049-9_5 fatcat:al2egz5monaujp766k7vxwlooi

New Free Distance Bounds and Design Techniques for Joint Source-Channel Variable-Length Codes

Amadou Diallo, Claudio Weidmann, Michel Kieffer
2012 IEEE Transactions on Communications  
For that purpose, it introduces improved techniques to bound the free distance of variable-length codes.  ...  This paper proposes branch-and-prune algorithms for searching prefix-free joint source-channel codebooks with maximal free distance for given codeword lengths.  ...  Among the proposed algorithms, the most efficient relies on the exploration of canonical tree representations, which describe the structure of equivalent prefix-free codebooks.  ... 
doi:10.1109/tcomm.2012.072412.110706 fatcat:bbnmzi4ypbcwtppubzvveg32ia

Optimizing the free distance of Error-Correcting Variable-Length Codes

Amadou Diallo, Claudio Weidmann, Michel Kieffer
2010 2010 IEEE International Workshop on Multimedia Signal Processing  
The aim is to find a prefix-free codebook with the largest possible free distance for a given set of codeword lengths, ℓ = (ℓ1, ℓ2, . . . , ℓM ).  ...  Three methods for building the tree of codebooks are presented and their efficiency is compared.  ...  ACKNOWLEDGMENTS The authors would like to thank Pierre Duhamel for helpful discussions and suggestions.  ... 
doi:10.1109/mmsp.2010.5662027 dblp:conf/mmsp/DialloWK10 fatcat:4aqnd54ucjeatejzmdmp3i4jaq

Page 4 of Journal of Research and Practice in Information Technology Vol. 26, Issue 1 [page]

1994 Journal of Research and Practice in Information Technology  
Note that, although the code is variable length, every stream of bits can be uniquely decoded into a stream of positive integers, and the code has the “prefix-free” property.  ...  For example, x = 15 has a unary prefix part of “1110” and a binary suffix partof “1 11". yielding atotal code of “1110111”. Some gamma codes for other values of x are shown in Table 2.  ... 

Compressing Feature Sets with Digital Search Trees

Vijay Chandrasekhar, Yuriy Reznik, Gabriel Takacs, David M. Chen, Sam S. Tsai, Radek Grzeszczuk, Bernd Girod
2011 2011 IEEE International Conference on Computer Vision Workshops (ICCV Workshops)  
State-of-the-art image retrieval pipelines are based on "bag-oj-words" matching.  ...  We propose a coding scheme based on Digital Search Trees that reduces size oj a set o.ff eatures by approximately log2(m!) bits.  ...  After scanning prefixes, we scan the suffix stream till we decode 2 Huffman prefix-free codes and reconstruct each feature descriptor. bits over a range of bitrates.  ... 
doi:10.1109/iccvw.2011.6130219 dblp:conf/iccvw/ChandrasekharRTCTGG11 fatcat:rhwcoy5yybaxhiqktzkqitsbmm

Space-Efficient Huffman Codes Revisited [article]

Szymon Grabowski, Dominik Köppl
2021 arXiv   pre-print
Canonical Huffman code is an optimal prefix-free compression code whose codewords enumerated in the lexicographical order form a list of binary words in non-decreasing lengths.  ...  Gagie et al. (2015) gave a representation of this coding capable to encode or decode a symbol in constant worst case time.  ...  Conclusion and Open Problems Canonical codes (e.g., Huffman codes) are an interesting subclass of general prefix-free compression codes, allowing for compact representation without sacrificing character  ... 
arXiv:2108.05495v1 fatcat:jnlh52nsufc6pbf6xpa4tf4ety

Compressing a set of CHoG features

Vijay Chandrasekhar, Sam S. Tsai, Yuriy Reznik, Gabriel Takacs, David M. Chen, Bernd Girod, Andrew G. Tescher
2011 Applications of Digital Image Processing XXXIV  
orderings, and if the order of transmission can be discarded, one can reduce the query size by an additional log 2 (m!) bits.  ...  We apply the two schemes to a set of low bitrate Compressed Histogram of Gradient (CHoG) features, and compare their performance. Both schemes achieve approximately log 2 (m!)  ...  After scanning prefixes, we scan the suffix stream until we decode 2 Huffman prefix-free codes and reconstruct each feature descriptor. An example of CHoG DST coding is illustrated in Figure 6 .  ... 
doi:10.1117/12.895431 fatcat:3xbhrwxgmzed7bgqidvn7tqjxe

Finite State Models in the Study of Comma-Free Codes

J. A. Llewellyn
1983 Computer journal  
Compact representations of comma-free binary 1 codes are given for variable length codewords with maximum even fixed lengths (6,8 and 10) and in one case (length not greater than 6) it is seen that the  ...  S = (xxx, yxy | prefix = xxy). Guibas and Odlyzko 1 discuss the choices of prefixes to maximise the number of codewords in a fixed length prefix code.  ...  There are well established efficient algorithms for achieving the unique canonical form.  ... 
doi:10.1093/comjnl/26.4.303 fatcat:3fpj7gw3ffgsdnlsf2ddjsdf4m

Kleenex: compiling nondeterministic transducers to deterministic streaming transducers

Bjørn Bugge Grathwohl, Fritz Henglein, Ulrik Terp Rasmussen, Kristoffer Aalund Søholm, Sebastian Paaske Tørholm
2016 Proceedings of the 43rd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages - POPL 2016  
, worst-case linear-time performance and sustained high throughput.  ...  such as AWK, sed, grep, RE2, Ragel and regular-expression libraries.  ...  The order of authors is insignificant; please list all authors-or none-when citing this paper.  ... 
doi:10.1145/2837614.2837647 dblp:conf/popl/GrathwohlHRST16 fatcat:e5nzqgpisban5lk44oi5hqcjty

Kleenex: compiling nondeterministic transducers to deterministic streaming transducers

Bjørn Bugge Grathwohl, Fritz Henglein, Ulrik Terp Rasmussen, Kristoffer Aalund Søholm, Sebastian Paaske Tørholm
2016 SIGPLAN notices  
, worst-case linear-time performance and sustained high throughput.  ...  such as AWK, sed, grep, RE2, Ragel and regular-expression libraries.  ...  The order of authors is insignificant; please list all authors-or none-when citing this paper.  ... 
doi:10.1145/2914770.2837647 fatcat:awp6t3efmva6xg5dlewzclsp6e

Optimizing hash-array mapped tries for fast and lean immutable JVM collections

Michael J. Steindorfer, Jurgen J. Vinju
2015 Proceedings of the 2015 ACM SIGPLAN International Conference on Object-Oriented Programming, Systems, Languages, and Applications - OOPSLA 2015  
The resulting general purpose design increases cache locality and features a canonical representation.  ...  It outperforms Scala's and Clojure's data structure implementations in terms of memory footprint and runtime efficiency of iteration (1.3-6.7 x) and equality checking (3-25.4 x).  ...  Acknowledgments We thank Mark Hills for providing PHP control flow graphs, and our colleagues and the anonymous referees for providing feedback on earlier drafts of this paper.  ... 
doi:10.1145/2814270.2814312 dblp:conf/oopsla/SteindorferV15 fatcat:2ldqqnjz2rex7f2cgdalgshvpi

Optimizing hash-array mapped tries for fast and lean immutable JVM collections

Michael J. Steindorfer, Jurgen J. Vinju
2015 SIGPLAN notices  
The resulting general purpose design increases cache locality and features a canonical representation.  ...  It outperforms Scala's and Clojure's data structure implementations in terms of memory footprint and runtime efficiency of iteration (1.3-6.7 x) and equality checking (3-25.4 x).  ...  Acknowledgments We thank Mark Hills for providing PHP control flow graphs, and our colleagues and the anonymous referees for providing feedback on earlier drafts of this paper.  ... 
doi:10.1145/2858965.2814312 fatcat:wc3s6s4q7rcipdpk6tb4bgafca

A binary decision diagram based approach for mining frequent subsequences

Elsa Loekito, James Bailey, Jian Pei
2009 Knowledge and Information Systems  
In terms of mining time, it can be substantially more efficient when the support is low, the number of patterns is large, or the input sequences are long and highly similar.  ...  In this paper, we introduce a new type of BDD, namely a Sequence BDD (SeqBDD), and show how it can be used for efficiently mining frequent subsequences.  ...  NICTA is funded by the Australian Government as represented by the Department of Broadband, Communications and the Digital Economy and the Australian Research Council through the ICT Centre of Excellence  ... 
doi:10.1007/s10115-009-0252-9 fatcat:d2hbnlxio5hw7p7begpicgima4

Canonical Prefixes of Petri Net Unfoldings [chapter]

Victor Khomenko, Maciej Koutny, Walter Vogler
2002 Lecture Notes in Computer Science  
Such a notion is based on a cutting context and results in the unique canonical prefix of the unfolding.  ...  the canonical prefix.  ...  Acknowledgements This research was supported by an Ors Awards Scheme grant ORS/C20/4, Epsrc grants GR/M99293 and GR/M94366 (Movie), and an Arc grant JIP.  ... 
doi:10.1007/3-540-45657-0_49 fatcat:uel5iffojfavpavmt2q6a7bqz4

Canonical prefixes of Petri net unfoldings

Victor Khomenko, Maciej Koutny, Walter Vogler
2003 Acta Informatica  
We prove that both algorithms, despite being non-deterministic, generate the canonical prefix.  ...  Such a notion is based on a cutting context and results in the unique canonical prefix of the unfolding.  ...  Acknowledgements This research was supported by an Ors Awards Scheme grant ORS/C20/4, and by Epsrc grants GR/M99293 and GR/M94366 (Movie).  ... 
doi:10.1007/s00236-003-0122-y fatcat:n76auledibdzrdnzssp7sw27uu
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