Signal encoding based on spectral requirements

A printed product package or printed product label comprising:

• a white substrate or printed white background comprising a first area;
• an ink mixture printed at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising extender white and Green 7 ink, the ink mixture comprising a volume or weight ratio of 97.5% to 99.75% white extender and 2.5% to 0.25% Green 7 ink;
• in which the first plurality of spatial locations is arranged in a pattern conveying an encoded signal, 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 of the 2-dimensional pattern, and
• in which the white substrate or white background and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8% to 30%.

A printed object comprising:

• a substrate comprising a first area;
• a first ink printed within the first area, the first ink comprising a spectral reflectivity of equal to or less than 10% at or around 660 nm;
• an ink mixture printed over the first ink at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising opaque white ink and Pantone® Rubine Red ink, the ink mixture comprising a volume or weight ratio of 68%-76% opaque white ink and 24%-32% Pantone® Rubine Red;
• in which the first plurality of spatial locations is arranged in a pattern conveying an encoded signal, and
• in which the first ink and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%.

An image processing method comprising:

• obtaining optically captured imagery representing a printed object, the imagery captured by a scanner have a peak illumination at or around 660 nm, the printed object comprising:
• a substrate or background comprising a first area, a first ink printed within the first area, the first ink comprising a spectral reflectivity of equal to or less than 10% at or around 660 nm, an ink mixture printed over the first ink at a first plurality of spatial locations within the first area, the ink mixture printed such that the first area comprises a second plurality of spatial locations without the ink mixture, the ink mixture comprising opaque white ink and Pantone® Rubine Red ink, the ink mixture comprising a volume or weight ratio of 68%-76% opaque white ink and 24%-32% Pantone® Rubine Red, in which the first plurality of spatial locations is arranged in a pattern conveying an encoded signal, and in which the first ink and the ink mixture comprise a spectral reflectivity difference at or around 660 nm in a difference range of 8%-30%;
• processing the captured imagery to decode the plural-bit payload from the encoded signal;
• outputting the plural-bit payload.