Closed form non-iterative watermark embedding
The present disclosure relates generally digital watermarking and data hiding. One claim recites: receiving data representing imagery; and then, using one or more processors: transforming the data into a multi-channel color space; determining an impact of adding a color channel watermark signal image to a color direction of the received data; determining a color space direction for watermark detection; determining weighting factors based on a determined impact; weighting the color channel watermark signal with signal embedding weighting factors to yield a modified color channel watermark signal; embedding the modified color channel watermark signal in the data representing imagery with consideration of the color direction. Of course, other claims and combination are provided as well.
1. A method comprising:
obtaining data representing imagery; and then,
using one or more processors:
transforming the data representing imagery into a multi-channel color space;
determining an impact of adding a color channel watermark signal to a color direction of the data representing imagery, in which said determining utilizes a relationship of local distortion introduced by the color channel watermark signal to local image data in the data representing imagery, processed by a Human Visual System (HVS) response;
determining a color direction for watermark detection;
determining weighting factors based on a determined impact;
weighting the color channel watermark signal with determined signal embedding weighting factors to yield a modified color channel watermark signal;
embedding the modified color channel watermark signal in the data representing imagery with consideration of a determined color direction.
2. The method of claim 1 in which one or more processors are programmed to carry out the method of claim 1 .
3. The method of claim 1 in which said embedding comprises altering data representing each pixel of the data representing imagery.
4. The method of claim 1 in which said embedding proceeds after transforming signal embedding weights to an embedding color space.
5. A non-transitory computer readable medium comprising instructions stored thereon to cause a programmed computer to perform the method of claim 1 .
6. The method of claim 1 further comprising: modeling a constant visibility surface in Lab color space as an axis-aligned ellipsoid.
7. A system comprising:
electronic memory for storing data representing imagery;
one or more electronic processors configured for transforming the data representing imagery into a multi-channel color space;
means for quantifying an impact of adding a color channel watermark signal to a color direction of the of the data representing imagery, in which said determining utilizes a relationship of local distortion introduced by the color channel watermark signal to local image data in the data representing imagery, processed by a Human Visual System (HVS) response;
means for determining a color direction for watermark detection;
means for quantifying weighting factors based on a determined impact;
means for weighting the color channel watermark signal with determined signal embedding weighting factors to yield a modified color channel watermark signal; and
one or more electronic processors configured for embedding the modified color channel watermark signal in the data representing imagery with consideration of a determined color direction.
8. The system of claim 7 in which said one or more electronic processors configured for embedding are configured for altering data representing each pixel of the data representing imagery.
9. The system of claim 7 in which said one or more electronic processors configured for embedding proceeds with embedding after transforming signal embedding weights to an embedding color space.
10. The system of claim 7 further comprising: means for generating a constant visibility surface in Lab color space represented as an axis-aligned ellipsoid.