Methods for encoding, decoding and interpreting auxiliary data in media signals

Abstract

The disclosure relates to digital watermarking, steganography, and specifically to message coding protocols used in conjunction with digital watermarking and steganographic encoding/decoding and payload interpretation methods. One claim recites a method for interpreting a data structure having fixed and variable message portions, the method comprising: processing the fixed message portion to determine a version of the variable message portion; decoding the entire payload field of the variable message portion according to the determined version; and interpreting only a portion of the decoded payload field according to the determined version. Of course, other features and claims are provided too.

1 . A variable message payload method for creating a payload in a data structure, comprising:
 forming a payload item identifier in a first portion of a payload field that identifies a payload item conveyed in a second portion of the payload field, in which the payload item identifier identifies a payload item sub-type to inform decoding of the payload item, the payload item representing a sell-by date, an expiration date or a best-if-used-by date;   forming error-correction bits to authenticate the payload field; and   embedding the payload item identifier, error-correction bits, and the payload item into a host media signal.   
     
     
         2 . The method of  claim 1 , wherein the data structure comprises a digital watermark. 
     
     
         3 . The method of  claim 1 , wherein embedding comprises embedding such that the data structure is substantially imperceptible in the host media signal. 
     
     
         4 . (canceled) 
     
     
         5 . The method of  claim 1 , wherein the identifier includes a global trade item number (GTIN), an application identifier (AI), or a recycling code. 
     
     
         6 . A method for interpreting a data structure having fixed and variable message portions, the method comprising:
 processing the fixed message portion to determine a version of the variable message portion, in which the fixed message portion identifies a type of error correction;   decoding a payload field of the variable message portion according to the determined version, including applying an error correction process to validate the variable message portion corresponding the type of error correction;   determining a payload item identifier in a first portion of a payload field of the decoded variable message portion, in which the payload item identifier identifies a payload item sub-type to inform interpretation of a payload item conveyed in a second portion of the decoded payload field, the payload item representing a sell-by date, an expiration date or a best-if-used-by date; and   interpreting the payload item conveyed in the second portion of the decoded payload field according to the determined payload item identifier.   
     
     
         7 . A method for interpreting a data structure having fixed and variable message portions, the method comprising:
 processing the fixed message portion to determine a version of the variable message portion, the fixed message portion comprising a validation portion and a version portion, said processing obtaining plural-bit data from the version portion, in which the validation portion comprises a fixed set of message symbols to provide a check to confirm valid processing;   decoding only a portion of the payload field of the variable message portion according to the determined version, in which the variable message portion comprises error detect symbols including a type and length of Cyclic Redundancy Check (CRC) symbol; and   interpreting a payload item conveyed in the decoded portion of the payload field.   
     
     
         8 . (canceled) 
     
     
         9 . A system, comprising:
 a processor; and   a memory coupled to the computer processor, the memory storing instructions that, when executed by the processor, cause the processor to perform the method recited in of  claim 6 .   
     
     
         10 . The system of  claim 9 , further comprising at least one capture device configured to capture a host media signal in which the data structure is encoded. 
     
     
         11 . The system of  claim 10 , wherein the at least one capture device comprises a microphone, a camera and an accelerometer. 
     
     
         12 . A non-transitory computer readable storage medium storing therein instructions that, when executed by a processor in a system cause the processor to perform the method recited in any of  claim 6 .