Method of embedding color information in printed documents using watermarking
View Patent ↗A method for enhancing color fidelity in multi-reproduction, includes scanning an image to be reproduced, wherein the image contains an invisible digital watermark including color information; decoding the color information contained in the watermark; comparing the decoded color information with the scanned image; generating a correction table from the differences between the decoded color information and the scanned image; and performing color correction on the scanned image using the correction table. This method confines the color error to one generation, even when copies go through multiple reproduction.
1. A method for enhancing color fidelity in multi-reproduction, comprising:
scanning an image to be reproduced, wherein the image contains a digital watermark including color information;
decoding the color information contained in the watermark;
comparing the decoded color information with the scanned image;
generating a correction table from the differences between the decoded color information and the scanned image; and
performing color correction on the scanned image using the correction table.
2. The method of claim 1 , further comprising completing the correction table using interpolation and extrapolation.
3. The method of claim 1 , wherein the color information comprises color information from sub-sampled smooth regions of the original image.
4. The method of claim 1 , wherein the color information contained in the watermark is compressed prior to encoding into the watermark and further comprising decompressing the compressed color information.
5. The method of claim 1 , wherein the digital watermark further includes edge information, registration information and information describing the color extraction technique.
6. The method of claim 1 , wherein the scanned image comprises a black and white image.