自适应块区域DWT低码率视频编码算法的研究

Adaptive blocking regional DWT video coding algorithm for low bit-rate

为了降低低码率视频编码算法的块效应与环效应，提出了一种基于块区域子波变换和重叠运动补偿的视频编码算法。通过分层游动窗块区域形成算法检测出帧间预测误差场的高能量区域，仅对这些区域进行子波变换和量化，有效节省码率，或在保持码率不变的条件下，有效的降低振荡环效应；根据人类视觉系统（ＨＶＳ）的空－频和时－频特性，给出基于ＨＶＳ的量化模型，以期在信噪比约束下获得最好的主观测试质量。模拟结果表明，对于公共交互格式（ＣＩＦ）图象，在低码率和甚低码率下仍能得到满意的图象质量。该算法可以应用于低码率视频会议系统中。

? A novel video coding algorithm based on blocking regional wavelet transform and overlapped motion compensation is described in this paper. The high energy regions of interframe predicted difference are first detected using hierarchical sliding window region forming algorithm. Wavelet decomposition and quantization are carried out only for these regions. This scheme reduces bit rate or gets distinct improvement in decoding video quality with cutting down ringing effects at the same bit rate compared with traditional coding algorithms. A quantization model based on human vision system (HVS) spatiality frequency and time frequency feature is used in coding algorithm. Simulation result shows acceptable image quality for common intermediate format (CIF) resolution at low bit rate and very low bit rate. 