ENCODING AND DECODING AN AUDIO WATERMARK

摘要

Embodiments of the invention are directed to systems, methods and computer program products for providing targeted location-based communications. An exemplary apparatus is configured to receive an encoded signal, decode the encoded signal such that embedded data is retrieved, send the embedded data a remote server; and receive a message based at least partially on sending the embedded data. Another exemplary apparatus is configured to provide the encoded signal by receiving data input, receiving a host signal, embedding the data input within the host signal such that an encoded signal is generated, and transmitting the encoded signal. A third exemplary apparatus is configured to provide the targeted communications by storing one or more messages associated with an entity, receiving data, selecting at least one of the one or more messages based at least partially on the data received, and sending the at least one of the one or more messages selected.

主权项

1. A system for creating an audio watermark signal by encoding a message comprising multiple bits of data, the message being encoded into a host signal in the audible frequency range, the system comprising at least one encoding device comprising a processing device to:
receive data representing a message to be encoded; retrieve at least one message vector comprising a plurality of frequency components grouped into a plurality of groups, each group corresponding to a different bit in the message, wherein the message vector has an equal number of positive components and negative components, each having substantially the same amplitude; read a frame of the host signal; transform the frame of the host signal from the time domain to the frequency domain, wherein the frame comprises a plurality of frequency components corresponding to the plurality of frequency components of the at least one message vector; apply the at least one message vector to the frame of the host signal, thereby resulting in an encoded frequency domain frame that represents all the multiple bits of data of the message; and
wherein applying the at least one message vector to the frame comprises multiplying each of the message vector frequency components by the corresponding frame frequency components, resulting in the encoded frequency domain frame; transform the encoded frequency domain frame from the frequency domain to the time domain, thereby resulting in an encoded time domain frame that represents all the multiple bits of data of the message; and compile the audio watermark signal based at least in part on the encoded time domain frame.