Patent ID: 6574004
Filing Date: 2003-06-03
Classification: H04N

Abstract:
A method for converting color data to gray data, the color data having one or more color components where each color component has a quantitative value ranging from a minimum quantitative value to a maximum quantitative value, the method comprising:specifying a target value for each color component and each combination of color components of the color data, the target value setting a shade of gray which corresponds to the maximum quantitative value for a corresponding color component or combination thereof; deriving a conversion equation to convert the color data into a shade of gray associated with the color data, the conversion equation equaling the sum of the products obtained by multiplying the quantitative value of each color component and each combination of color components with an associated coefficient; determining a gray scale boundary condition equation for each of the color components and the combinations of color components by substituting the maximum quantitative values into the conversion equation for any color component present in the color data and the minimum quantitative values for any color component not present in the color data; determining the coefficients for each color component and for each combination thereof using the gray scale boundary condition equations and the target values; receiving the color data; and converting the color data to gray data by solving the conversion equation using the quantitative values for each color component and for each combination of color components and their associated coefficients.