Finite Automata Computing Real Functions
SIAM Journal on Computing
String matching in Lempel-Ziv compressed strings
STOC '95 Proceedings of the twenty-seventh annual ACM symposium on Theory of computing
Automata, Languages, and Machines
Automata, Languages, and Machines
On the Complexity of Pattern Matching for Highly Compressed Two-Dimensional Texts
CPM '97 Proceedings of the 8th Annual Symposium on Combinatorial Pattern Matching
Pattern-Matching Problems for 2-Dimensional Images Described by Finite Automata
FCT '97 Proceedings of the 11th International Symposium on Fundamentals of Computation Theory
Algorithms on Compressed Strings and Arrays
SOFSEM '99 Proceedings of the 26th Conference on Current Trends in Theory and Practice of Informatics on Theory and Practice of Informatics
| Hi-index | 0.00 |
We investigate how the size of the compressed version of a 2-dimensional image changes when we cut off a part of it, e.g. extracting a photo of one person from a photo of a group of people. 2-dimensional compression is considered in terms of finite automata. Let n be the size of the smallest acyclic automaton which describes an image T. We show that the tight bound for the compression size of a subsegment (subimage) in the deterministic case is Θ(n2:5) and in the weighted case is Θ(n). We also show how to construct efficiently the compressed representation of subsegments given the compressed representation of the whole image. Two applications of subsegments compression are more efficient automata-compressed pattern-matching and the first polynomial time algorithm for the fully compressed pattern-checking problem for weighted automata.