Patent · US Expired

Image processing apparatus

US4833721A · kind A · utility

27Cited by
4References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 11, 1988
Grant dateMay 23, 1989
Priority date
Expiry dateFeb 11, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06V10/754
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An image processing apparatus comprises a detector which includes an image reading section of a digital copier and which chases outline information of an image pattern in a predetermined direction and thereby extracts outline points; an arithmetic operating circuit to respectively obtain outline tangential directions on the basis of the outline points; an extracting circuit to select a predetermined number of extraction points from the outline points; a coding circuit to sequentially obtain direction differences in the outline tangential directions on the basis of the extraction points and to code the direction differences; and a recognizing circuit to perform a non-linear matching between a code sequence coded by the coding circuit and a reference code sequence, thereby recognizing the image pattern. The coding circuit calculates the outline tangential directions using predetermined direction codes. With this apparatus, an image pattern can be stably and accurately recognized at high speed without being influenced by positional deviation, rotation, change in size, or the like of the image pattern.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.