python中的拉普拉斯算子是什么

import cv2 as cv
    import matplotlib.pyplot as plt
    
    # 读取图像
    img = cv.imread('data.jpg', cv.COLOR_BGR2GRAY)
    rgb_img = cv.cvtColor(img, cv.COLOR_BGR2RGB)
    
    # 灰度化处理图像
    grayImage = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
    
    # Laplacian
    dst = cv.Laplacian(grayImage, cv.CV_16S, ksize = 3)
    Laplacian = cv.convertScaleAbs(dst)
    
    # 用来正常显示中文标签
    plt.rcParams['font.sans-serif'] = ['SimHei']
    
    # 显示图形
    titles = ['原始图像', 'Laplacian 算子']
    images = [rgb_img, Laplacian]
    
    for i in range(2):
        plt.subplot(1, 2, i + 1), plt.imshow(images[i], 'gray')
        plt.title(titles[i])
        plt.xticks([]), plt.yticks([])
    plt.show()