Patent ID: 6125199
Filing Date: 2000-09-26
Classification: H04N

Abstract:
A color correcting method comprising:converting a first color signal of a first format into a second color signal of a second format using a conversion matrix,said first format being a format used by an imaging device, said conversion matrix being associated with said imaging device,said conversion matrix being obtained based on an achromatic color component conversion matrix and a chromatic color component conversion matrix representing chromaticity and achromaticity of said imaging device; andinversely converting said second color signal into a third color signal of a third format, said third format being a format used by an image output unit,said inverse converting being performed using an inverse conversion matrix, said inverse conversion matrix being obtained based on an inverse of a conversion matrix associated with said image output unit, and said conversion matrix associated with said image output unit being obtained based on an achromatic color component conversion matrix and chromatic color component conversion matrix representing chromaticity and achromaticity of said image output unit,wherein said conversion matrix associated with said imaging device is mathematically independent of said conversion matrix associated with said image output unit; andwherein said achromatic color component conversion matrix and said chromatic color component conversion matrix associated with said imaging device are generated according to the steps of:setting an achromatic color vector associated with said imaging device based on a white point and black point associated with said imaging device;setting chromatic color vectors based on points of three primary colors in said first format associated with said imaging device;decomposing each chromatic color vector into a first and second vector based on said achromatic color vector, said first vector being parallel to said achromatic color vector, and said second vector being perpendicular to said achromatic color vector;determining said achromatic color component conversion matrix in accordance with said first vector decomposed from each of said chromatic color vectors;determining said chromatic color component conversion matrix in accordance with said second vector decomposed from each of said chromatic color vectors; andwherein said determining said chromatic color component conversion matrix step includes the steps of:determining third vectors, each third vector having the same direction and corresponding to one of said second vectors, said third vectors being determined such that a sum of said third vectors equals zero, and a sum of the differences between magnitudes of each third vector and a corresponding one of said second vectors is a minimum; anddetermining said chromatic color component conversion matrix in accordance with said third vectors.