import cv2

# Canny算子
def CannyFilter(img):
    # 读取图像
    src = img

    ########## Begin ##########
    # 1. 高斯滤波
    blur = cv2.GaussianBlur(src, (3, 3), 0)
    # 2. 灰度转换
    blur = cv2.cvtColor(blur, cv2.COLOR_BGR2GRAY)
    # 3. 求x，y方向的Sobel算子
    gradx = cv2.Sobel(blur, cv2.CV_16SC1, 1, 0)
    grady = cv2.Sobel(blur, cv2.CV_16SC1, 0, 1)
    # 4. 使用Canny函数处理图像，x,y分别是3求出来的梯度，低阈值50，高阈值150
    edge_output = cv2.Canny(gradx, grady, 50, 150)
    ########## End ##########

    return edge_output