Image restoration from a downsampled image by using the DCT
Image restoration from a downsampled image by using the DCT
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DOI：
10.1016/j.sigpro.2007.03.010
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发表时间：
2007-10
期刊：
影响因子：
--
通讯作者：
Y. Abe;Y. Iiguni
中科院分区：
文献类型：
--
作者：
Y. Abe;Y. Iiguni
提出了一种利用离散余弦变换(DCT)从低分辨率(LR)图像中恢复高分辨率图像的方法。将下采样过程建模为矩阵形式，并将离散余弦变换应用于下采样矩阵，得到稀疏矩阵表示。然后利用稀疏性从LR图像中高效地计算出恢复的HR图像。从理论上分析了观测噪声引起的失真，证明了失真的功率近似等于观测噪声的方差。计算机仿真结果表明，在加性噪声较小的情况下，该方法的恢复效果优于三次样条插值法。
The high-resolution (HR) image restoration from a downsampled low-resolution (LR) image by using the discrete cosine transform (DCT) is proposed. The downsampling process is modeled in matrix form and the DCT is applied to the downsampling matrix to obtain the sparse matrix representation. The restored HR image is then efficiently computed from the LR image by using the sparsity. The distortion caused by the observation noise is theoretically analyzed, and the power of distortion is shown to be closely equal to the variance of the observation noise. Computer simulations show that the proposed method is superior to the cubic spline interpolation in the HR image restoration performance as far as the amount of the additive noise is small.