Method of matching hardcopy colors to video display colors in which unreachable video display colors are converted into reachable hardcopy colors in a mixture-single-white (MSW) color space
Method for color image processing
Color processing system
Color image processing with adjustment of computed recording color to match original color
Color printing method and apparatus using an out-of-gamut color table
Methods and apparatus for multigeneration color image processing
Color estimation method for expanding a color image for reproduction in a different color gamut Patent #: 5317426
ApplicationNo. 197055 filed on 02/16/1994
US Classes:345/611, Anti-aliasing or image smoothing358/515Color separation
ExaminersPrimary: Herndon, Heather R.
Assistant: Vo, Cliff N.
Attorney, Agent or Firm
Foreign Patent References
International ClassH04N 001/46
AbstractA method of smoothing a color lookup table minimizes inappropriate shifts away from gray, at the same time reducing the effect of measurement errors and enabling interpolation between the lookup table data points to be performed efficiently. More particularly, data in a preliminary lookup table, comprising a three-dimensional data array in which a location of each data point is designated by a unique tuple, is smoothed so as to satisfy predetermined constraints. A resulting three-dimensional lookup table relates source device colors and destination device colors in a computer graphics system in which a color image source device and a color image destination device have non-coincident color gamuts. The method is performed by, beginning at a data point representing white and concluding at a data point representing black, comparing a data point representing an adjacent shade of gray to neighboring data points and, if a color component of one or more of the neighboring data points differs in value from the same color component of the data point by more than a predetermined amount, adjusting the value of the color component of the one or more neighboring data points such that the color component of the one or more neighboring data points does not differ in value from the color component of the data point by more than the predetermined amount. Related data points whose tuples differ from a tuple of the data point in only one dimension are then compared to neighboring data points. The foregoing steps are repeated until the entire lookup table has been smoothed.