Patent · US Expired

Image tone interpolation method and apparatus therefor

US5999658A · kind A · utility

5Cited by
4References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 26, 1997
Grant dateDec 7, 1999
Priority date
Expiry dateJun 26, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06T2207/20192
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

All possible image levels of image data are input to tone conversion characteristics, and a tone jump included in the image after tone conversion is detected from the resultant output data. An A-type contour line and a B-type contour line constituting the contours of a target area for tone interpolation are obtained from the multi-tone image. The target area is then detected by checking the inclusive relationship between the A-type and B-type contour lines to extract at least one set of contour lines indicating the contour of the target area. In the target area, an area defined by the A-type contour line and the B-type contour line is divided into (N+1) divided areas, and N intermediate image levels are sequentially allocated to the N divided areas of the (N+1) divided areas.

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