【摘要】 视频在无线易错信道上传输,报文丢失会导致图像质量显著下降。多参考帧选择方法可以降低误码扩散,从而提高误码信道上传输视频的图像质量。但是参考帧选择方法也使得编码器计算复杂度大大增加。基于多参考帧选择技术提出一种低复杂度的率失真优化方法。该方法首先在编码器上重建误码图像,使得编码器和解码器上的参考图像一致,然后利用端到端率失真优化模型,在重建的误码图像与编码图像的上一帧图像中选择最优的参考帧。在进行率失真计算时,采用线性预测方法计算运动补偿后图像差值的方差,减少了运动估计运算,从而大大降低计算复杂度。实验结果表明相对于帧内刷新方法该方法显著提高图像质量,相对于一般多参考帧选择方法,在损失很小性能的情况下,大大降低了计算复杂度。更多还原

【Abstract】 Packet loss led to great degradation of picture quality, when video stream transmitted in error-prone channel. RPS (Reference picture selection) could improve picture quality by selecting suitable reference picture, but RPS greatly increased computation complexity. In this paper one low complex RPS optimal method was proposed. First error concealment steps in decoder was tracked in encoder to reconstruct error picture; second only error reconstructed picture and the preceding picture were taken as optional reference pictures; third picture difference variance was computed by linear prediction when processing R-D optimization. Through above means time of motion estimation was reduced, and then computation complexity was greatly decreased. Experiment result shows the method greatly lower encoder’s complexity, while only loss small picture quality.更多还原