Data hiding for spot colors on substrates
AssigneeDigimarc Corporation
InventorsAlastair M. Reed, Tomas Filler, Kristyn R. Falkenstern, Yang Bai
Life of this patent
Estimating the term…
Abstract
The present disclosure relates generally to data hiding for retail product packaging and other printed objects such as substrates. One embodiment embeds an information signal in a spot color for printing on various substrates. The spot color is screened, and overprinted with process color tint. The tint is modulated prior to overprinting with optimized signal tweaks. The optimization can include consideration of a detector spectral dependency (e.g., red and/or green illumination). Many other embodiments and combinations are described in the subject patent document.
Claims17
A substrate comprising:
- a first printed area, the first printed area comprising a combination of i) data representing a first color (S1), and ii) data representing a second color (S2), in which encoded information is provided on said substrate through modulation of the data representing the second color (S2) with max (positive) and min (negative) tweaks;
- in which the combination has been optimized by:
- determining a color error between data representing third color data (S3) and a combination of S1 and S2,
- determining an information modulating error associated with the max and min tweaks;
- and
- finalizing the combination of S1 and S2, including minimizing the color error and minimizing the information modulating error;
- and
- a second printed area including a barcode;
- a third printed area including text information printed thereon.
An image processing system for generating a design for a substrate comprising:
- memory storing data representing a first color (S1);
- one or more multi-core processors configured for:
- minimizing:
- i) a color match error between (S1) and a combination of data representing second color data (S2) and data representing third color data (S3), the combination including auxiliary encoded information in (S3), and ii) an information modulating error associated with modulations of (S3) that carry the auxiliary encoded information,
- said minimizing being constrained by a spectral component associated with an anticipated information detector,
- obtaining color percentage values associated with at least (S3) and a signal strength value for regulating the modulations;
- an output configured for outputting the color percentage values and signal strength value;
- a signal encoder configured for encoding a signal in the design using the color percentage values and signal strength value, said signal encoder generating an encoded design;
- and
- a signal detector configured for determining signal robustness associated with the encoded design.
An image processing method comprising:
- obtaining color data representing a spot color ink;
- obtaining data representing a process color ink tint, the process color ink tint including at least a Cyan (C) component, a Magenta (M) component and a Yellow component (Y);
- determining an overprinting of the process ink tint with the color data;
- decomposing the process ink tint into a maximum signal tweak and a minimum signal tweak, each of the maximum signal tweak and the minimum signal tweak having a Cyan (C) component, a Magenta (M) component and a Yellow component (Y);
- minimizing a color error metric of the overprinting relative to the data representing the spot color ink;
- optimizing the maximum signal tweak and the minimum signal tweak according to at least a spectral dependency, in which said optimizing comprises determining color weights and a global signal strength;
- transforming the process color ink tint with the maximum signal tweak and the minimum signal tweak to represent an information signal, the color weights for application to the process color tint, and the global signal strength for application to the maximum signal tweak and the minimum signal tweak, said transforming yielding a transformed process color ink tint;
- determining a robustness associated with the transformed process color ink tint;
- outputting the transformed process color ink tint for overprinting with the color data.
Dependencies are inferred from the claim text.