Reversible discrete cosine transform
Reversible discrete cosine transform
复制标题
可逆离散余弦变换
DOI：
10.1109/icassp.1998.681802
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
K. Sezaki
中科院分区：
文献类型：
--
作者：
K. Komatsu;K. Sezaki
本文提出了可逆离散余弦变换（RDCT）。首先提出N点可逆变换，然后用2点可逆变换和4点可逆变换分别代替构成8点离散余弦变换(DCT)的2点和4点变换，得到8点RDCT。尽管变换系数是整数，但可以无损地恢复整数输入信号。如果在 RDCT 中忽略下取函数，则变换与行列式=1 的 DCT 完全相同。 RDCT也被归一化，这样我们就可以避免动态范围不均匀的问题。对连续色调静态图像的模拟表明，RDCT 的无损和有损压缩效率与可逆小波变换获得的效率相当。
In this paper a reversible discrete cosine transform (RDCT) is presented. The N-point reversible transform is firstly presented, then the 8-point RDCT is obtained by substituting the 2 and 4-point reversible transforms for the 2 and 4-point transforms which compose the 8-point discrete cosine transform (DCT), respectively. The integer input signal can be losslessly recovered, although the transform coefficients are integer numbers. If the floor functions are ignored in RDCT, the transform is exactly the same as DCT with determinant=1. RDCT is also normalized so that we can avoid the problem that dynamic range is nonuniform. A simulation on continuous-tone still images shows that the lossless and lossy compression efficiencies of RDCT are comparable to those obtained with reversible wavelet transform.