Image processing apparatus
US5134503A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 19, 1990 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Jul 19, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The image processing apparatus of the present invention determines the number of surrounding pixels to be averaged and their locations, determines a weighting coefficient based on the density and contrast levels of an input image data derived from a continuous tone image, and performs an averaging operation on the input image signal by performing a weighting operation using the averaged result of the surrounding pixels, the input image data, and the weighting coefficient. Therefore, the image processing apparatus of the present invention is capable of reducing the noise level over a wide range of image types, from shadow regions with high density. Further to highlight regions with low density, and images reproduced by this apparatus do not exhibit a deterioration of the sharpness of image boundaries in the high density regions, images characterized by a gradual change in the density level do not turn out having an unnatural quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.