Underwater video compression using the wavelet transform

Abstract

The advances in autonomous underwater vehicle (AUV) technology and underwater acoustic communications have spawned a considerable amount of research activity within the area of signal and information processing. AUVs equipped with video hardware can provide invaluable visual data to ocean researchers for exploration of the undersea environment. In the past, a popular medium for the transport of underwater video from the vehicle to a remote platform has been a fiber optic link. Such tethered AUVs have a limited range of exploration, therefore an idea has previously been proposed to capture and process video on-board an untethered vehicle then transmit it using underwater telemetry. Video communication requires a considerably larger bandwidth than that which an underwater acoustic channel may provide therefore massive data compression must take place prior to transmission from the AUV. This work addresses the compression problem by presenting a wavelet-based hybrid video encoder for low bit-rate encoding of underwater video. Results show that compression rates on the order of 100:1 may be achieved with good visual quality in the reconstructed video.