Method and apparatus for color-correcting multi-channel signals of a digital camera
AssigneeEastman Kodak Company
InventorsKevin E. Spaulding, Richard M. Vogel, Jeffrey R. Szczepanski
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Abstract
Multi-channel color image signals from a digital camera having multi-channel image sensors are corrected to account for variations in scene illuminant. This is accomplished by determining the scene illuminant and determining an optimum color-correction transformation in response to the scene illuminant which transform minimizes color errors between an original scene and a reproduced image by adjusting three or more parameters.
Claims29
A method for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant comprising the steps of:
- a) determining the scene illuminant;
- and
- b) determining an optimum illuminant-dependent color-correction transformation based on the determined scene illuminant which transformation minimizes color errors between an original scene and a reproduced image when applied to the multi-channel color signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals.
A method for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant comprising the steps of:
- a) determining the scene illuminant;
- and
- b) determining an optimum color-correction transformation in response to the scene illuminant which transformation minimizes color errors between an original scene and a reproduced image when applied to the multi-channel color image signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals wherein the optimum color-correction transformation determining step includes combining the color errors for a set of typical scene colors and determining the optimum color-correction transformation that minimizes the combined error.
A method for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant comprising the steps of:
- a) determining the scene illuminant;
- and
- b) determining an optimum color-correction transformation in response to the scene illuminant which transformation minimizes color errors between an original scene and a reproduced image when applied to the multi-channel color image signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals wherein the color-correction transformation is a color-correction matrix having adjustable matrix coefficients.
A method for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant comprising the steps of:
- a) determining the scene illuminant;
- b) classifying the scene illuminant into one of a set of possible scene illuminants;
- and
- b) selecting an optimum illuminant-dependent color-correction transformation based on the classified scene illuminant from a set of color-correction transformations, each transformation having been predetermined to minimize color errors between an original scene and a reproduced image for a particular classified scene illuminant when applied to the multi-channel color image signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals.
A method for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant comprising the steps of:
- a) determining the scene illuminant;
- b) determining channel-dependent neutral-balance transformations based on the determined scene illuminant to be applied to the multi-channel color image signals for form neutral-balanced color image signals, the neutral-balance transformations being adapted to produce equal signal levels for scene colors that are neutral;
- and
- c) determining an optimum illuminant-dependent color-correction transformation based on the determined scene illuminant which transformation minimizes color errors between an original scene and a reproduced image when applied to the multi-channel color image signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals.
An apparatus for color-correcting multi-channel color image signals from a digital camera having multi-channel image sensors to account for variations in scene illuminant, comprising:
- a) means for determining the scene illuminant;
- and
- b) means for determining an optimum illuminant-dependent color-correction transformation based on the determined scene illuminant which transformation minimizes color errors between an original scene and a reproduced image when applied to the multi-channel color image signals to produce multi-channel color output signals, each of such multi-channel color output signals being dependent upon more than one of the multi-channel color image signals.
Dependencies are inferred from the claim text.