能量梯度函数

理论

能量梯度函数更适合实时评价图像清晰度，该函数定义如下：

https://blog.csdn.net/Real_Myth/article/details/50827940

代码

def energy(img):
    '''
    :param img:narray 二维灰度图像
    :return: float 图像约清晰越大
    '''
    shape = np.shape(img)
    out = 0
    for x in range(0, shape[0]-1):
        for y in range(0, shape[1]-1):
            out+=((int(img[x+1,y])-int(img[x,y]))**2)+((int(img[x,y+1]-int(img[x,y])))**2)
    return out

https://blog.csdn.net/Greepex/article/details/90183018