图像金字塔定义:同一图像的不同分辨率的子图集合
1.pyrDown和pyrUp
向下取样:dst=cv2.pyrDown(src)
向上取样:dst=cv2.pyrUp(src)
向下取样的原理:
向上取样原理:
程序示例:
import cv2
import numpy as np
img=cv2.imread("lena.bmp",cv2.IMREAD_UNCHANGED)
up1=cv2.pyrUp(img)
down1=cv2.pyrDown(up1)
cv2.imshow("orignial",img)
cv2.imshow("Up",up1)
cv2.imshow("down1",down1)
cv2.waitKey()
cv2.destroyAllWindows()
结果:
将图像像下取样在向上取样,丢失的信息是无法还原的。
2.拉普拉斯金字塔
拉普拉斯金字塔定义:
dst=src-PyrUp(PyrDown(src))
程序示例:
import cv2
import numpy as np
img=cv2.imread("lena.bmp",cv2.IMREAD_UNCHANGED)
img2=cv2.pyrDown(img)
img2=cv2.pyrUp(img2)
lapPyr=img-img2
cv2.imshow("orignial",img)
cv2.imshow("result",lapPyr)
cv2.waitKey()
cv2.destroyAllWindows()
结果: