Image processing method and apparatus

Patent 5479537 Issued on December 26, 1995. Estimated Expiration Date:

December 26, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Logarithmically normalized cross-correlation bar-code reader
Patent #: 3986000
Issued on: 10/12/1976
Inventor: McJohnson

Confirmed boundary pattern matching
Patent #: 5018218
Issued on: 05/21/1991
Inventor: Peregrim, et al.

Image processing apparatus Patent #: 5068746
Issued on: 11/26/1991
Inventor: Ohsawa, et al.

Inventors

Assignee

Nikon Corporation

Application

No. 880592 filed on 05/08/1992

US Classes:

382/266, Edge or contour enhancement382/199, Pattern boundary and edge measurements382/218, Comparator382/263Highpass filter (i.e., for sharpening or enhancing details)

Examiners

Primary: Boudreau, Leo H.
Assistant: Anderson, Harold D.

Attorney, Agent or Firm

Shapiro and Shapiro

International Class

G06K 009/40

Foreign Application Priority Data

1991-05-13 JP

Abstract

In an image processing method of effecting the pattern matching of an input image and a pre-memorized reference image, the reference image is pre-memorized in memory means and the input image is input to input means. The reference image and the input image obtained from the memory means and the input means, respectively, have the same differential filters applied thereto by differentiation means, whereby a differential reference image and a differential input image are obtained. The differential reference image and the differential input image are input to differential correlation value calculation means or inner product sum calculation means, whereby the cross-correlation value or the inner product sum of these is calculated, and the local maximum value of the cross-correlation value or the inner product sum is found by image recognizing means to thereby find the relative positional relation between the reference image and the input image.