基于小波变换的高斯点扩展函数估计

点扩展函数估计是图像复原的重要内容,目前还没有精确估计的算法。根据小波理论,提出了新的高斯型点扩展函数精确估计算法。算法首先对模糊图像作平滑处理,抑止噪声;然后对图像进行不同尺度小波变换,并分别计算出变换后小波模极大值;再根据推导出的不同尺度下小波模极大值、李氏指数、方差三者之间的关系,准确计算出高斯点扩展函数的方差。实验结果表明,算法的估计精度高,达到了95%左右,具有重要的应用价值。

Wavelet transform based Gaussian point spread function estimation

Point spread function (PSF) estimation, an essential part for image restoration, has no accurate estimation algorithm at present. Based on the wavelet theory, a new Gaussian PSF accurate estimation algorithm is put forward. Firstly, the blurred images are smoothed, and their noise is reduced. Secondly, wavelet with varied scales is transformed, after which the local maxima of the modulus of the wavelet are computed respectively. Thirdly, on the basis of the relation deduced among the local maxima of the modulus of the wavelet at different scales, Lipschitz exponent and variance, the variance of a Gaussian PSF is computed. The experimental result shows that the proposed algorithm has an accuracy rate as high as 95%, and is of great application value.