2-DIMENSIONAL PATTERN-MATCHING BY SAMPLING

We extend the concept of deterministic sampling to the two-dimensional pattern matching problem. We show that almost all patterns have a logarithmic deterministic sample. There are 2D-matching algorithms which work efficiently for almost all patterns. They solve the 2D-matching problem in linear sequential time with O(1) space, or, alternatively in O(1) parallel time with linear number of processors. This is the first attempt to reduce the space for two-dimensional pattern matching.