Apparatus and method for pattern recognition

A method and an apparatus for pattern recognition are described. Features characterizing at least two significant portions or regions of the printed pattern on a model document are extracted from a scanned-in image of the model document. Statistical characteristics of each significant region are calculated from the extracted features and saved in a memory. In addition, geometrical relationships, e.g. distances and angles, between the regions are also saved in a memory. The geometrical relationships are represented by the coordinates of the regions in a predetermined coordinate system, e.g. the x-y coordinate system corresponding to the scan area on the platen of a scanner. When a new or trial document is scanned and examined through a search window, features are extracted from the search window blocks and compared to the statistical characteristics of the model document previously stored in memory. If there is a match, the coordinates of the search window having the matching features in the trial document are recorded in a candidate list. After the entire trial document has been processed, the geometric relationships between the window blocks on the candidate list are compared with the geometrical relationships of the matching significant region blocks of the model document and if the relationships correspond the trial document is considered a match.