image pyramid
reduce=高斯模糊+降采样 PyrDown
expand=扩大+卷积 PyrUp还原
Gaussian Pyramid
Laplacian Pyramid
import cv2 as cv
import numpy as np
#图像金字塔reduce过程
def pyramid_demo(image):
level = 3
temp = image.copy()
pyramid_images = []
for i in range(level):
dst = cv.pyrDown(temp)
pyramid_images.append(dst)
cv.imshow("pyramid_down_"+str(i), dst)
temp = dst.copy()
return pyramid_images
#图像expend过程和原图相减 得到拉普拉斯金字塔
def lapalian_demo(image):
pyramid_images = pyramid_demo(image)
level = len(pyramid_images)
for i in range(level-1, -1, -1):#从高到低 递减 从低分辨率到高分辨率 还原图像
if (i-1) < 0 :
expand = cv.pyrUp(pyramid_images[i], dstsize=image.shape[:2])
lpls = cv.subtract(image, expand)
cv.imshow("lapalian_down_" + str(i), lpls)
else:
expand = cv.pyrUp(pyramid_images[i], dstsize=pyramid_images[i-1].shape[:2])
lpls = cv.subtract(pyramid_images[i-1], expand)
cv.imshow("lapalian_down_"+str(i), lpls)
if __name__=='__main__':
print("--------- Python OpenCV Tutorial ---------")
src = cv.imread("../opencv-python-img/lena.png")#图像大小是2的倍数不然会出错。
cv.namedWindow("input image", cv.WINDOW_AUTOSIZE)
cv.imshow("input image", src)
#pyramid_demo(src)
lapalian_demo(src)
cv.waitKey(0)
cv.destroyAllWindows()