Image processing method based on processing of interrelated image gradients
US4561022A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 1983 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | Aug 11, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/409
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved image processing method prevents unwanted processing artifacts from degrading the reproduction of an image by stressing the interrelationship of various image gradients in the image. Image signals are generated representative of the light value of elements of the image. A local gradient signal is generated in response to a combination of image signals representative of an image gradient over a local portion of the image. An extended gradient signal is also generated representative of an image gradient over an image portion greater than the local portion. The image gradients are interrelated in a composite signal generated from a combination of the local and extended gradient signals. As an example of the combination, the composite signal is made to vary as a function of the difference between the gradient signals. The image signals are then modified subject to a characteristic of the composite signal, e.g., the magnitude of the composite signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.