Tonal conversion method for a faded color photographic original picture
US5212518A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1992 |
| Grant date | May 18, 1993 |
| Priority date | — |
| Expiry date | Apr 8, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4072
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Herein disclosed is a tonal conversion method for a faded color original picture useful upon producing a printed picture in a halftone from a faded color photographic original in a continuous tone. As picture information of tonal conversion, unfaded light intensity values (Xn) of a pixel in a faded color photographic original, instead of density information values (D.sub.Fn) of a corresponding pixel of the same, are used. The light intensity values (Xn) may be rationally determined, utilizing an assumption of dye loss and density characteristic curves (S-DCC) of a photographic photosensitive material. The light intensity values (Xn) are then converted into halftone dot area % values by conduction of a specific tonal conversion formula.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.