Patent ID: 7957560

Claim:
An unusual action detector comprising: differential data generating means for generating inter-frame differential data from moving image data comprised of image frame data; feature data extracting means for extracting feature data from three-dimensional data comprised of immediately adjacent inter-frame differential data on a pixel-by-pixel basis through cubic higher-order local auto-correlation; pixel-by-pixel feature data generating means for adding the extracted feature data for pixels within a predetermined range including each of pixels spaced apart by a predetermined distance; index calculating means for calculating an index indicative of unusualness of feature data generated by said pixel-by-pixel feature data generating means with respect to a subspace of a usual action; unusualness determining means for determining unusualness when the index is larger than a predetermined value; and outputting means for outputting the result of the determination which declares unusualness for a pixel position for which said unusualness determining means determines unusualness; the unusual action detector further comprising: principal component subspace generating means for finding the subspace which exhibits the usual action based on a principal component vector from extracted feature data in the past in accordance with a principal component analysis approach; and a classifying means for finding an index of similarity based on a canonical angle of a subspace found from pixel-by-pixel feature data generated by said pixel-by-pixel feature data generating means to the subspace which exhibits the usual action, and classifying a screen on a pixel-by-pixel basis using a clustering approach, wherein said principal component subspace generating means adds the feature data on a class-by-class basis to calculate a class-by-class subspace, and said index calculating means calculates an index indicative of unusualness of the feature data generated by said pixel-by-pixel feature data generating means with respect to the class-by-class subspace.