Auxiliary information for reconstructing digital images processed through print-scan channels

An image processing method, comprising:

• obtaining scanned image data from a hard copy of output image data containing an input image;
• decoding an auxiliary data structure associated with the output image data to produce decoded auxiliary information;
• estimating locations of corners of the input image in the scanned image data;
• warping the scanned image data within the estimated corner locations to obtain sample points in the scanned image data;
• registering the portion of the scanned image data within the estimated corner locations based on correspondences between the reference pixel values in the decoded auxiliary information and values of sample points at corresponding locations in the scanned image data;
• deriving a color transform between ones of the reference pixel values in the auxiliary data structure and values of corresponding ones of the sample points of the registered image;
• and
• applying the color transform to the registered image to obtain a color-corrected image.

An image processing system, comprising:

• an auxiliary information processing component that extracts auxiliary information, including values of reference pixels, from an input image;
• an encoding processing component that encodes the auxiliary information into an auxiliary data structure;
• and
• an output image processing component that generates output image data containing a representation of the input image;
• wherein at least one of the encoding processing component and the output image processing component stores the auxiliary data structure in association with the output image data in at least one physical storage medium.