Signal encoding for difficult environments
This disclosure relates to advanced image signal processing technology including encoded signals and digital watermarking. We disclose methods, systems and apparatus for selecting which ink(s) should be selected to carry an encoded signal for a given machine-vision wavelength for a retail package or other printed design. We also disclose retail product packages and other printed objects, and methods to generate such, including a sparse mark in a first ink and an overprinted ink flood in a second ink. The first ink and the second ink are related through tack and spectral reflectance difference. Of course, other methods, packages, objects, systems and apparatus are described in this disclosure.
1. A method of providing a design for a printed object comprising:
obtaining information associated with a first substrate comprising a first area, the first area comprising a first region and a second region;
providing an encoded signal arranged in a sparse mark pattern to be printed within the second region with a first ink so that the second region comprises a top layer of ink flood using a second ink, a middle layer of sparse mark pattern and a bottom layer of first substrate, in which the first region is to be printed to comprise a top layer of ink flood using the second ink and a layer of first substrate;
obtaining information associated with the second ink to be printed over the sparse mark pattern and the first substrate within the second region, in which the second ink comprises a greater tack or adhesion with the first substrate relative to the second ink's tack or adhesion with the first ink;
determining whether the first region and the second region comprise a spectral reflectance difference at a machine-vision wavelength in the range of 8%-60%; and
selecting a different combination of first ink and second ink when the spectral reflectance difference at a machine-vision wavelength is not within the range of 8%-60%.
2. The method of claim 1 in which the range comprises 12%-20%.
3. The method of claim 1 in which the spectral reflectance difference comprises 12% or higher within a range of 12%-60%.
4. The method of claim 1 in which the first region comprises a darker region relative to the second region.
5. The method of claim 1 in which first reflectance values for the first ink at the machine-vision wavelength account for a package's fill.
6. The method of claim 5 in which the first ink is to be overprinted on a clear plastic substrate.
7. The method of claim 6 in which second reflectance values for the substrate or the second ink at the machine-vision wavelength account for package fill.
8. The method of claim 7 in which first substrate comprises the clear plastic substrate.
9. The method of claim 1 in which the printed object comprises a product hag tag.
10. The method of claim 1 in which the printed object comprises a product label.
11. The method of claim 1 in which the sparse mark pattern comprises a 2-dimensional pattern comprising a payload component and a synchronization component, in which the sparse mark pattern retains payload component elements and synchronization component elements that are compatible at the same spatial coordinates as one another within the 2-dimensional pattern.
12. A printed object comprising: a first substrate comprising a first area, the first area comprising a first region and a second region, in which the second region comprises an encoded signal arranged in a printed 2-dimensional pattern, the encoded signal comprising a payload component and a synchronization component, in which the encoded signal retains payload component elements and synchronization component elements that are compatible at the same spatial coordinates as one another within the 2-dimensional pattern, the 2-dimensional pattern printed with a first ink so that the second region comprises a top layer of ink flood using a second ink, a middle layer of printed 2-dimensional pattern and a bottom layer of first substrate, and in which the first region comprises a printed top layer of ink flood using the second ink and a layer of first substrate, in which the second ink comprises a greater tack or adhesion with the first substrate relative to the second ink's tack or adhesion with the first ink, and in which the first region and the second region comprise a spectral reflectance difference at a machine-vision wavelength in the range of 8%-60%.
13. The printed object of claim 12 in which the range comprises 12%-20%.
14. The printed object of claim 12 in which the spectral reflectance difference comprises 12% or higher within a range of 12%-60%.
15. The printed object of claim 12 in which the first region comprises a darker region relative to the second region.
16. The printed object of claim 12 in which the first substrate comprises a clear plastic substrate.
17. The printed object of claim 16 in which the clear plastic substrate comprises packaging surrounding a dark fill.
18. The printed object of claim 16 in which the clear plastic substrate comprises packaging surrounding a light fill.
19. The printed object of claim 12 in which the first substrate comprises product packaging.