POST-COMPRESSION HIDDEN DATA TRANSPORT FOR VIDEO

摘要

Auxiliary data (315, 414) is carried substantially imperceptibly with video transform data in combined transform samples according to a visibility threshold. The auxiliary data (315, 414) provides a capability for a copy protect scheme of verification of television viewing activity. The video transform samples (240) are extracted from the compressed packetized data stream and normalized if required. The auxiliary data (315, 414) modulates data carrier sequences such as pseudo-noise (PN) spread spectrum signals (412, 630) in different spatial frequencies to provide auxiliary data subband samples (SPD0-SPD N-1), which are in turn combined with the video transform samples (SS0-SS N-1) in one or more spatial frequencies to provide combined subband samples. The combined transform samples (SS'0-SS'N-1) are then multiplexed into the packetized data stream (462). In a decoder (368), the combined transform samples are demodulated to recover the auxiliary data signal (672).