Faster two dimensional scaled matching

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, proportionally enlarged according to an arbitrary real-sized scale, in a given text. The currently fastest known algorithm for this problem uses techniques from dictionary matching to solve the problem in O(nm ³+n ² mlog∈m) time using O(nm ³+n ²) space, where T is a two-dimensional n×n text array and P is a two-dimensional m×m pattern array. We present a new approach for solving the scaled matching problem improving both the running time and the space requirements. Our algorithm runs in O(n ² m) time and uses O(n ²) space.