Patent · US Expired

Tonal conversion method of pictures for producing reproduced pictures free of color-fog

US5057931A · kind A · utility

11Cited by
4References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 16, 1990
Grant dateOct 15, 1991
Priority date
Expiry dateFeb 16, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/6027
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A tonal conversion method of pictures useful upon producing reproduced pictures such as halftone pictures free of color-fog from color-fogged color original pictures of continuous tone. The tonal conversion is conducted in a manner that objective data relating to color-fog from a color original picture having color-fog thereon are obtained using undistorted X-axis pictorial information values for respective C, M and Y color plates obtained from the corresponding density values on the D axis in accordance with corresponding density characteristic curves of R, G, B photosensitive emulsion layers of a color film used upon photographing the original color pictures, thereby providing reproduced pictures free of color-fog by using a specific tonal conversion formula.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.