关键词: 水下视频编码, 全局运动估计, 全局-局部运动补偿

Abstract: This paper presents an efficient underwater video compression algorithm.The algorithm mainly consists of three modules：Namely preprocessing of underwater images，global motion estimation，and hybrid global-local motion compensation.A discrete wavelet transform based preprocessing approach is employed to effectively reduce the visual redundancy underwater images.Global motion parameters are estimated by using a fast and robust feature-point based algorithm.The proposed hybrid global-local motion compensation scheme is easy to implement.The experimental results show that while maintaining the acceptable perceptual quality of the reconstructed images，the proposed algorithm can provide high coding efficiency，especially applying to sea floor video compression and transmission at very low bit rates to meet the limited bandwidth requirement of underwater acoustic channels.

Key words: underwater video coding, global motion estimation, global-local motion compensation