基于率失真优化的快速帧内更新算法

A Real Time Intra-Update Method Based on Rate-Distortion Optimization

提出了一种近似估计整帧图像最小量化失真度的模型和新的率失真优化的实时帧内更新准则,可使编码器直接计算出编码一帧图像的最小量化失真度,通过评估宏块帧内编码所增加的总量化失真度和减小的扩散失真度,以决定是否需要对此宏块进行帧内更新。经与传统的基于率失真的帧内更新相比和实验结果表明,更新算法在具有更小计算复杂度的同时,在大多数情况下可以取得更好的峰值信噪比值。

A rate-distortion computation model is established for approximately estimating the total quantization distortion of one frame, and a new real time Intra-update criterion is proposed. Through comparing the increased quantization distortion and reduced propagation distortion by intra-updating, the encoder can quickly decide which macroblock need to be intra-updated. Simulation results show that the performance of proposed algorithm, which reduces the computational complexity significantly, achieves the same or even better gains over traditional rate-distortion based Intra-update methods.