Cross-camera color constancy using calibrated color correction matrices

A method for cross-camera color constancy, the method comprising:

• receiving a raw image from a camera and color correction matrices (CCMs) including a first CCM corresponding to a first correlated color temperature and a second CCM corresponding to a second correlated color temperature;
• generating a camera fingerprint embedding (CFE) by transforming predefined illuminant chromaticities from a device-independent color space into a raw RGB color space of the camera using interpolation between the CCMs, and encoding the transformed illuminant chromaticities into a CFE vector;
• converting the raw image into a histogram representation using log-chroma mapping;
• concatenating the CFE vector with the histogram representation to form a combined feature representation;
• and
• estimating an illuminant color in the raw RGB color space of the camera through an illuminant estimation neural network based on the combined feature representation.

A non-transitory computer-readable storage medium storing instructions that, when executed by at least one processor, cause the at least one processor to:

• receive a raw image from a camera and color correction matrices (CCMs) including a first CCM corresponding to a first correlated color temperature and a second CCM corresponding to a second correlated color temperature;
• generate a camera fingerprint embedding (CFE) by transforming predefined illuminant chromaticities from a device-independent color space into a raw RGB color space of the camera using interpolation between the CCMs, and encoding the transformed illuminant chromaticities into a CFE vector;
• convert the raw image into a histogram representation using log-chroma mapping;
• concatenate the CFE vector with the histogram representation to form a combined feature representation;
• and
• estimate an illuminant color in the raw RGB color space of the camera through an illuminant estimation neural network model based on the combined feature representation.