Method and apparatus for determining the sharpness of images
US3984184A · kind A · utility
6Cited by
10References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1975 |
| Grant date | Oct 5, 1976 |
| Priority date | — |
| Expiry date | Aug 6, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/462
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The variation in transparency along the surface of an original is detected and a corresponding transparency-indicating signal is generated. The spectral components of the transparency-indicating signal having frequencies above a predetermined frequency associated with sharp images are integrated to form an integration signal corresponding to the time integral of these higher-frequency spectral components. The determination of whether the original bears an image whose sharpness warrants copying of the original is made by comparing the integration signal against a reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.