高效的DCT域图像任意比率下采样方法

Efficient method for DCT-domain image arbitrary downsampling

提出了一种新DCT域任意m:n比率的下采样方法,即直接找出输入m 2个块与下采样输出的n 2个的块的DCT系数关系式。实验结果表明:本方法的重构图像的峰值信噪比(PNSR)优于Park方法0.5dB,且有较低的计算复杂性,适用于任何基于DCT压缩的视频转码方案。

A novel approach to resize Images with m/n resizing ratio in the DCT domain,was proposed which expoits the relationship of DCT coefficients between m^2 input blocks and n ^2 output blocks. Experimental results confirm that the scheme performs about 0.5dB better than Park＇s method in terms of PNSR of reconstructed image with a comparable computational speed.The proposed method can be used to any DCT-based compressed video transcoding applications.