SPOT COLOR SUBSTITUTION FOR DIGITAL WATERMARKING

摘要

The present disclosure relates generally to digital watermarking for spot colors. In one implementation a substitute spot color+CMY tint is selected to replace an original spot color. The CMY tint can be transformed to carry a digital watermark signal. Of course, other features, combinations and technology are described herein.

主权项

1. A digital watermark embedding method comprising:
obtaining data associated with a spot color Sa, the spot color Sa comprising a component of a color design; using one or more configured processors, determining a screen Ss of the spot color Sa; selecting a substitute spot color candidate Sb1 by: i) evaluating color distance or color error between the substitute spot color candidate Sb1 and the screen Ss, and ii) evaluating brightness of the substitute spot color candidate Sb1 and the screen Ss; using one or more configured processors, determining a Cyan (C), Magenta (M) and Yellow (Y) process color tint that when combined with the substitute spot color candidate Sb1 approximates the spot color Sa; transforming a determined CMY process color tint with a digital watermark signal to embed the digital watermark signal in the CMY process color tint, said transforming yielding a watermarked CMY process color tint; and combining the watermarked CMY process color tint and the substitute spot color candidate Sb1, said combining yielding a digital watermarked substitute spot color.