点扩展函数的参数辨识对于图像复原具有非常重要的意义。运动模糊和散焦模糊是常见的两种图像模糊类型。针对这两种模糊以及成像过程往往存在噪声的情况，提出了一种基于双谱的点扩展函数参数辨识的方法。介绍了这两种模糊类型及其传统的计算公式。推导了两种模糊类型的双谱，理论上双谱不仅不受噪声的影响，并且具有与模糊函数相似的结构，由此利用传统的模糊参数计算公式就可以计算出模糊参数。实验结果表明，本方法适用于含有噪声的一定模糊参数范围内的散焦模糊和运动模糊图像，即在模糊参数不太大的情况下，本方法可以取得更准确的结果。在信噪比为25 dB 的情况下，辨别出该范围内的模糊尺度的偏差不超过1 个像素。

The parameter identification of the point spread function is very important for image restoration. Motion blur and defocus blur are the common blur types which degrade image. For the two blur types, a robust bispectrum-based method is proposed to estimate the blur parameters in noisy images. At first, we introduce the two blur types and traditional computational formulas. And then, the bispectrum of two blur types is deduced. In theory, bispectrum is not affected by noise, and corresponds to similar structure of blur function, so we can calculate the blur parameters easily by using the traditional computational formulas. The experimental results show that our method is effective in a certain range. In other words, when the blur parameters are not too large, our method can complete the parameter identification more accurately. When SNR is 25 dB，the deviation of blur parameters recognized is less than 1 pixel in this range.