什么是图像金字塔？

向上采样 ：cv.pyrUp(img)

向下采样 : cv.pyrDown(img)

代码实现

import numpy as np
import cv2 as cv
import matplotlib.pyplot as plt

#图像的读取
img = cv.imread("lena.png")

#进行图像采样
up_img = cv.pyrUp(img)  #上采样

down_img = cv.pyrDown(img)  #下采样

#图像显示
cv.imshow("enlarge",up_img)
cv.imshow("original",img)
cv.imshow("shrink",down_img)

cv.waitKey(0)
cv.destroyWindow()

结果展示