import cv2

img = cv2.imread("./images/13.jpg")

for i in range(3):
    cv2.imshow(f"img{i}",img)
    img = cv2.pyrUp(img)

cv2.waitKey(0)

import cv2

img = cv2.imread("./images/13.jpg")

for i in range(3):
    cv2.imshow(f"img{i}",img)
    img = cv2.pyrDown(img)
cv2.waitKey(0)

import cv2
img = cv2.imread("./images/12.jpg")
img_down = cv2.pyrDown(img)
img_up = cv2.pyrUp(img_down)
img_new = cv2.subtract(img,img_up)

img_new = cv2.convertScaleAbs(img_new,alpha=5,beta=0)

cv2.imshow("img_LP",img_new)

cv2.waitKey(0)

import cv2
import numpy as np

A = cv2.imread("./images/21.jpg")
B = cv2.imread("./images/22.jpg")


# 生成高斯A
G = A.copy()
gpA = [G]

for i in range(6):
    G = cv2.pyrDown(G)
    gpA.append(G)


# 生成高斯金字塔B

G = B.copy()
gpB = [G]
for i in range(6):
    G = cv2.pyrDown(G)
    gpB.append(G)


# 生成拉普拉斯金字塔A
lpA = [gpA[5]]
for i in range(5,0,-1):
    GE = cv2.pyrUp(gpA[i])
    L = cv2.subtract(gpA[i-1],GE)
    lpA.append(L)

# 生成拉普拉斯B
lpB = [gpB[5]]

for i in range(5,0,-1):
    GE = cv2.pyrUp(gpB[i])
    L = cv2.subtract(gpB[i-1],GE)
    lpB.append(L)

#
LS = []
for i,(la,lb) in enumerate(zip(lpA,lpB)):
    rows,cols,dpt = la.shape
    ls = np.hstack((la[:,0:cols//2],lb[:,cols//2:]))
    LS.append(ls)
#
ls_ = LS[0]

for i in range(1,6):
    ls_ = cv2.pyrUp(ls_)
    ls_ = cv2.add(ls_,LS[i])
    cv2.imshow(f"xxx{i}",ls_)

cv2.waitKey(0)