OTSU分割算法

OTSU是阈值分割中一种常用的算法，它可以根据图像自动生成最佳分割阈值。OTSU的核心思想是类间方差最大化。

import cv2
import numpy as np
from matplotlib import pyplot as plt

image = cv2.imread("2.bmp")
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

plt.subplot(131), plt.imshow(image, "gray")
plt.title("source image"), plt.xticks([]), plt.yticks([])
plt.subplot(132), plt.hist(image.ravel(), 256)
plt.title("Histogram"), plt.xticks([]), plt.yticks([])
ret1, th1 = cv2.threshold(gray, 0, 255, cv2.THRESH_OTSU) #方法选择为THRESH_OTSU
plt.subplot(133), plt.imshow(th1, "gray")
plt.title("OTSU,threshold is " + str(ret1)), plt.xticks([]), plt.yticks([])
plt.show()