Summary: ALPHABET INDEPENDENT AND DICTIONARY
SCALED MATCHING \Lambda
Amihood Amir y Gruia C–alinescu z
Georgia Tech Georgia Tech
and
Bar­Ilan University
Abstract
The rapidly growing need for analysis of digitized images in multimedia systems has
lead to a variety of interesting problems in multidimensional pattern matching. One of
the problems is that of scaled matching, finding all appearances of a pattern in a text
in all sizes. Another important problem is dictionary matching, quick search through a
dictionary of preprocessed patterns in order to find all dictionary patterns that appear
in the input text.
In this paper we provide a simple algorithm for two dimensional scaled matching.
Our algorithm is the first linear­time alphabet­independent scaled matching algorithm.
Its running time is O(jT j), where jT j is the text size, and is independent of j\Sigmaj, the size
of the alphabet. The main idea behind our algorithm is identifying and exploiting a
scaling­invariant property of patterns.
Our technique generalizes to produce the first known algorithm for scaled dictionary
matching. We can find all appearances of all dictionary patterns that appear in the

Source: Amir, Amihood - Computer Science Department, Bar Ilan University

Collections: Mathematics