自适应阈值

opencv提供函数：

#自适应阈值
import sys,cv2,math
import numpy as np
import matplotlib.pyplot as plt
def adaptiveThresh(I,winSize,ratio=0.15):
    #均值平滑
    I_mean = cv2.boxFilter(I,cv2.CV_32FC1,winSize)
    out = I - (1.0-ratio)*I_mean
    out[out>=0] = 255
    out[out<0] = 0
    out = out.astype(np.uint8)
    return out
if __name__ =='__main__':
    src = cv2.imread('E:/sy2/6/image3.png',cv2.IMREAD_GRAYSCALE)   
    ra = adaptiveThresh(src,(7,7))
    print(ra)
    cv2.imshow('ra',ra)
    cv2.waitKey(0)
    cv2.destroyAllWindows()