Image recognition method and apparatus
US5805727A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 5, 1995 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Dec 5, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/2504
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A non-compressed template image is compared with compressed object images stored in a memory to find an object image corresponding to the template image. Each object image is DCT transformed and compressed according to JPEG algorithm such that the compressed image data includes DCT coefficients representing DC components which indicate average intensity or brightness of the respective block of the object image. The template image is processed to obtain average intensity for each of blocks corresponding in size to the blocks of the object image. Image recognition is performed by rough matching and fine matching. In the rough matching, the average intensity of the template image and the average intensity of the object image represented by the DC components are used to examine the degree of matching. When a maximum rough matching value is found, the object image is restored or decompressed and the fine matching is done with use of pixel intensity. The rough matching is carried out using DC components without restoration of the compressed image which involves an enormous amount of computations, and only the compressed image with the maximum rough matching value is restored. This reduce…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.