一种多步骤多分支H.264帧内预测模式选择算法

A Multi-Step and Multi-Branch Intra-Prediction Mode Decision Algorithm for H.264

提出了一种用于H.264/AVC编码的多步骤多分支快速帧内模式选择算法.该算法首先利用整数DCT域的频率分布特点有效减少了候选预测模式的数量,然后使用经过改进的率失真优化模型和H.264原有模型有选择地处理上述模式,并得到最优模式.通过实验发现在图像峰值信噪比(PSNR)和编码比特率基本不变的情况下,编码时间降低到了原来的1/6～1/3,从而达到了降低计算复杂度和提高编码效率的目的.

A multi - step and multi - branch fast intra - prediction mode decision algorithm for H. 264/AVC is proposed. The algorithm first uses frequency distributing characteristics of the integer DCT transform domain to filter out several unlikely candidate modes efficiently and then an improved rate - distortion model and the original model in H. 264 are applied selectively to the remaining candidate mode to obtain the optimized ones. Experimental results demonstrate that this algorithm reduces the encoding time to 1/6 - 1/3 of the original mode decision with nearly the same PSNR and encoding bitrate. The aim to reduce the computing complexity and increase the encoding efficiency is achieved.