Digital watermarking applications
In one aspect, assembly of multi-part food packaging is checked by reference to payloads of steganographically-encoded digital watermarks printed across the packaging components. Marking all surfaces of the packaging components allows arbitrary orientation of feed stock in assembly equipment, and wide latitude in placement of inspection cameras along the packaging line. In another aspect, a scanner at a retail checkout station is alert to any gap detected in steganographic encoding on retail product packaging and, if found, alerts an operator to possible presence of an adhesive label with a misleading barcode. A great variety of others features and arrangements are also detailed.
1. A system comprising:
a camera system disposed in a checkout area of a retail store;
a processor, configured by software instructions stored in a memory, to perform actions including:
processing image data, captured by the camera system from product packaging, to decode GTIN data encoded in a steganographic digital watermark on said product packaging;
processing said image data to decode GTIN data encoded in a barcode on said product packaging; and
comparing the GTIN data decoded from the steganographic digital watermark first machine-readable code with the GTIN data decoded from the barcode second machine-readable code to determine whether they correspond.
2. The system of claim 1 in which the software instructions further configure the system to issue an alert signal when there is a mismatch between the GTIN data decoded from the steganographic digital watermark and the GTIN data decoded from the barcode second machine-readable code.
3. The system of claim 2 in which the alert signal includes a signal to store staff alerting said staff to the possible presence of an adhesive barcode label on said packaging.
4. The system of claim 1 in which the steganographic digital watermark on the product packaging comprises an array of sparse elements set at coordinates within a two-dimensional block at which first and second watermark signal components provide compatible modulation, the first watermark signal component encoding the GTIN data, and the second watermark signal facilitating synchronization of a watermark decoder with the first watermark signal component.
5. A non-transitory computer-readable medium containing software instructions for configuring a processor-based computer system to perform acts including:
processing image data, captured by a camera system from product packaging, to decode GTIN data encoded in a steganographic digital watermark on said product packaging;
processing said image data to decode GTIN data encoded in a barcode on said product packaging; and
comparing the GTIN data decoded from the steganographic digital watermark with the GTIN data decoded from the barcode to determine whether they correspond.
6. The computer-readable medium of claim 5 in which said instructions further configure the computer system to issue an alert signal when there is a mismatch between the GTIN data decoded from the steganographic digital watermark and the GTIN data decoded from the barcode.
7. A system comprising:
a camera system disposed in a checkout area of a retail store to capture imagery of product packaging;
a digital watermark decoder configured to decode GTIN data encoded in a steganographic digital watermark on said product packaging from said imagery;
a barcode decoder configured to decode GTIN data encoded in a barcode on said product packaging from said imagery; and
a processor, configured by software instructions stored in a memory, to compare the GTIN data decoded from the steganographic digital watermark with the GTIN data decoded from the barcode to determine whether they correspond.
8. The system of claim 7 in which said software instructions further configure the processor to issue an alert signal when there is a mismatch between the GTIN data decoded from the steganographic digital watermark and the GTIN data decoded from the barcode.
9. The system of claim 7 in which the digital watermark decoder comprises a means for decoding GTIN data encoded in a steganographic digital watermark on said product packaging from said imagery.