Automated tone correction apparatus and method using filtered histogram equalization
US5426517A · kind A · utility
75Cited by
7References
26Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1992 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Nov 30, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing system redistributes image luminance values in an image represented in u'v'L* space to achieve a near-optimal fit of luminance data to available dynamic range and to enhance the shape and detail of the resultant image. Redistribution may be accomplished by passing the image through a filter having a peak response at a spatial frequency at which the human eye is highly sensitive, and then equalizing a cumulative histogram of filtered pixels. An image may be transformed to compensate for tone compression which accompanies printing processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.