H.26L中整数变换的研究及改进

Research and Improvement of the Inte ger Transform in H.26L

针对DCT变换存在浮点运算、运算量大等问题,H.26L提出了整数变换,它能够很好地消除浮点运算,避免逆变换不匹配,但存在精度不高的问题。在基于提升结构(liftingstructure)的无乘法二进制DCT(binDCT)的基础上,对参数进行选择优化,并将浮点DCT、整数变换和binDCT在结构和性能上进行比较分析,选择一组binDCT参数,使binDCT既能避免浮点运算又能降低运算量,且更有利于压缩。

Because the true DCT is a floating -point transform and has the IDCT mismatch problem,H.26L proposes the integer transforms approximati on to the DCT.It can well avoid these p roblems,but has low performance.Then a lifting -based fast approximation of the 4-point DCT,named the binDCT is proposed,which can be implemented with only a ddition and right -shift operations.We comp are and analyze the DCT,the integer t ransforms and the binDCT.The experimental results show that the binDCT with right param eters can not only reduce the complexity but also be more efficient.