对数变换

import cv2
import copy
import math
import matplotlib.pyplot as plt
o=cv2.imread('C:/Users/xpp/Desktop/Lena.png',cv2.IMREAD_GRAYSCALE)#原始图像
cv2.imshow("original",o)
logc=copy.deepcopy(o)
rows=o.shape[0]
cols=o.shape[1]
for i in range(rows):#对数变换
    for j in range(cols):
        logc[i][j]=3*math.log(1+logc[i][j])
cv2.imshow("result",logc)        
cv2.waitKey()
cv2.destroyAllWindows()