Color digital halftoning with vector error diffusion
Apparatus and method for color selection
Computer system with monochrome display unit capable of converting color code to gradation code
Method and apparatus for rapid scanning of color images
Color processing system Patent #: 5243414
ApplicationNo. 965685 filed on 10/22/1992
US Classes:345/591Color processing in perceptual color space
ExaminersPrimary: Nguyen, Phu K.
Attorney, Agent or Firm
Foreign Patent References
International ClassG06F 015/20
AbstractA method of rendering a color image on a designated output medium is disclosed which maps colors to the gamut of the designated output medium while preserving the semantic consistency of the object color and illumination information in the image. The method performs gamut mapping earlier in the image synthesis process than current gamut method methods, at the point where information about object primitives and their spectral attributes in a scene description is available, but after the fixed scene geometry has been determined by the rendering system. The method makes use of the output of a symbolic rendering system which produces symbolic pixel expressions, having basis spectra variables which represent the interplay of light and object primitives in the scene description, and spectral data having color information about the light and object primitives in the scene, and which is indexed to the basis spectra variables. The method performs spectral change calculations using the symbolic pixel expressions, the spectral data, and spectral information about the gamut of the specific output medium to determine the modifications to the original spectral data that need to be made to the individual object primitives in the scene in order to produce image pixel colors which are in the gamut of the output medium. The resulting image colors are locally and globally consistent with the semantics of the image, make effective use of as much of the available gamut of the display device as is possible, and require no further post-rendering gamut mapping prior to display or reproduction on the designated medium.
Field of SearchSpecific signal processing circuitry