Patent ID: 6778704
Filing Date: 2004-08-17
Classification: G06K

Abstract:
A pattern recognition method for determining the category of an unknown pattern, the category being one of a set of categories corresponding to a set of known patterns, the method comprising:providing a subcategory-level recognition dictionary adapted to store reference information for each one of plural subcategories obtained by partitioning the categories comprising the category set, wherein each of the categories is partitioned into the subcategories by at least one partitioning vector; receiving a pattern signal representing the unknown pattern and processing the signal to extract a feature vector therefrom; selecting the reference information of one subcategory of each category in the recognition dictionary in response to the feature vector, the reference information of one subcategory of each category being selected from the recognition dictionary, and calculating the inner product of the feature vector and at least one partitioning vector; and determining a distance between the feature vector and the selected reference information of the subcategory of each category to determine the category of the unknown pattern; wherein there are n partitioning vectors, n being a positive integer; and wherein selecting the reference information of one subcategory of each category in the recognition dictionary further comprises: initializing an index i to 0, i being a positive integer, and iterating the following processes upon the index i being less than n: comparing the i-th inner product with a threshold and generating Zi(k)=1 when the inner product is greater than the threshold and otherwise generating Zi(k)=0; and accumulating the results of multiplying 2i by Zi(k) to generate an index of a selected subcategory.