color image processing method and apparatus for correcting a color signal from an input image device

Claim 2

A color image processing method for correcting R, G, and B color signals output from an arbitrary image input device, comprising the sequential steps of: obtaining a model variable of a first transform matrix with respect to a selected all color samples; transforming the R, G and B output signals from said image input device with respect to the color samples into the color space value using the first transform matrix; and determining error characteristics based on the color space value transformed in said transforming step, dividing the color space into regions, and selecting a model of each region, calculating the variable value of a model, and storing the calculated value in a second transform matrix for each region.

Claim 3

A color image processing method according to claim 1, wherein region dividing is carried out according to a hue shift inclination change of said color image input device.

Claim 4

A color image processing method according to claim 1, wherein region dividing is carried out according to a reflectance or lightness inclination change.

Claim 5

A color image processing method according to claim 1, wherein region dividing is carried out by considering both a hue shift inclination change and a reflectance or lightness inclination change.

Claim 6

A color image processing apparatus for correcting the color signal from an arbitrary image input device, comprising: a first transform matrix for holding model variables for a transform matrix with respect to selected all color samples (distributed in gamut of an image input device) and for transforming R, G, and B output signals from said image input device into a color space value; a region discriminator for discriminating a region to which a transformed color space value by said first transform matrix belongs and for selecting a second transform matrix (one of TM of the respective regions 50); and transform matrices for holding model variables for respective regions and for transforming the color space value (converted from R, G, and B signals) into the final value of the color space.

Claim 7

A color image processing apparatus for correcting the color signal from an arbitrary image input device, comprising: a first transform matrix for holding model variables for a transform matrix with respect to selected all color samples (distributed in gamut of an image input device) and for transforming R, G, and B output signals from said image input device into a color space value; a region discriminator for discriminating a region to which a transformed color space value by said first transform matrix belongs and for selecting a second transform matrix (one of TM of the respective regions 50); and transform matrices for holding model variables for respective regions and for transforming the color space value (converted from R, G, and B signals) into the final value of the color space.

Claim 8

A color image processing apparatus according to claim 5, wherein the color space is CIEXYZ.

Claim 9

A color image processing method for correcting R, G, and B color signals output from an arbitrary image input device, comprising the steps of: obtaining a model variable of a first transform matrix with respect to a selected color sample having a colorimetric color space value; transforming the R, G, and B output signals from the arbitrary image input device with respect the selected color sample into a color space value using the first transform matrix; determining error characteristics based on the color space value transformed in said transforming step; dividing the color space into regions responsive to the error characteristics in accordance with a conversion between the colorimetric color space value of the selected color sample and the color space value; selecting a model for each of the regions using the colorimetric color space value and the color space value; determining a variable value of the model for each of the regions; and converting the variable value for each of the regions using a second transform matrix into corrected R, G, and B signals for independent color processing.

Claim 10

A color image processing method for correcting R, G, and B color signals output from an arbitrary image input device, comprising the steps of: obtaining a model variable of a first transform matrix with respect to a selected color sample having a colorimetric color space value; transforming the R, G, and B output signals from the arbitrary image input device with respect the selected color sample into a color space value using the first transform matrix; determining error characteristics based on the color space value transformed in said transforming step; dividing the color space into regions responsive to the error characteristics in accordance with a conversion between the colorimetric color space value of the selected color sample and the color space value; selecting a model for each of the regions using the colorimetric color space value and the color space value; determining a variable value of the model for each of the regions; and converting the variable value for each of the regions using a second transform matrix into corrected R, G, and B signals for independent color processing.