均值滤波python实现不调用opencv

                                                                            数字图像均值滤波

1. 滤波的作用：

对数字图像进行滤波其主要目的是消除其中的噪声，保留图像中的有用信息平滑图像，因此图像滤波也叫图像平滑。图像和数字信号也有共同之处，就是有用信息基本都在低频段或者中频段，这也是信号滤波的基础。

2、均值滤波原理：

均值滤波过程中，使用周围像素点的均值来代替中心点的值。其数学解释在于，当某一个点的远低于或者远大于其他像素点的值时，使用均值代替该点的值可以使得该点更接近于真实值。

3、代码

def Mean_Filter(self, padding = None):

    imgarray = self.Add_Salt_Noise()
    height, width = imgarray.shape[0], imgarray.shape[1]

    if not padding:
        edge = int((self.k -1)/2)
        if height -1 -edge <=edge or width -1-edge<=edge:
            print("the kenerl is to long")
            return  None
        for i in range(height):
            for j in range(width):
                if i <=edge -1 or i >= height -1 -edge or  j <=edge -1 or j >= height -1 -edge:
                    imgarray[i][j] = imgarray[i][j]
                else:
                    num = []
                    sum0 = 0
                    sum1 = 0
                    sum2 = 0
                    for m in range(i - edge, i + edge + 1):
                        for n in range(j -edge, j+edge + 1):
                            sum0 = sum0 + imgarray[m][n][0]
                            sum1 = sum1 + imgarray[m][n][1]
                            sum2 = sum2 + imgarray[m][n][2]
                    mean0 = sum0 / (self.k * self.k)
                    mean1 = sum1 / (self.k * self.k)
                    mean2 = sum2 / (self.k * self.k)
                    mean =[mean0, mean1, mean2]
                    print("mean", mean)

                    imgarray[i][j] = mean #赋值
        new_img = Image.fromarray(imgarray)
        new_img.save(self.mean_img)

def Add_Salt_Noise(self): # 加椒盐噪声
    img = Image.open(self.source_img)
    imgarray = np.array(img)
    height,width = imgarray.shape[0], imgarray.shape[1]
    for i in range(height):
        for j in range(width):
            if np.random.random(1) < 0.05:
                if np.random.random(1) < 0.3:
                    imgarray[i][j] = 0
                else:
                    imgarray[i][j] = 255
    new_img = Image.fromarray(imgarray)
    new_img.save(self.noise_img)
    return imgarray