约束最小二乘方滤波要求噪声的方差和均值，这些参数可通过给定的退化图像计算出来，这是约束最小二乘方滤波的一个重要优点。(Constrained least square square filtering requires the variance and mean of noise. These parameters can be calculated by a given degraded image. This is an important advantage of constrained least square square filtering.)