opencv学习（二十五）：分水岭算法

代码如下：

#导入cv模块
import cv2 as cv
import numpy as np


# 分水岭算法
def water_image():
    print(src.shape)
    blurred = cv.pyrMeanShiftFiltering(src, 10, 100)  # 去除噪声

    # gray\binary image   灰度/二值化图像
    gray = cv.cvtColor(blurred, cv.COLOR_BGR2GRAY)#转化为灰度图像
    ret, binary = cv.threshold(gray, 0, 255, cv.THRESH_BINARY | cv.THRESH_OTSU)#二值化
    cv.imshow("binary-image", binary)

    # morphology operation  形态学操作
    kernel = cv.getStructuringElement(cv.MORPH_RECT, (3, 3))
    mb = cv.morphologyEx(binary, cv.MORPH_OPEN, kernel, iterations=2)
    sure_bg = cv.dilate(mb, kernel, iterations=3)
    cv.imshow("mor-opt", sure_bg)

    # distance transform 距离变换
    dist = cv.distanceTransform(mb, cv.DIST_L2, 3)
    dist_output = cv.normalize(dist, 0, 1.0, cv.NORM_MINMAX)
    cv.imshow("distance-t", dist_output * 70)

    ret, surface = cv.threshold(dist, dist.max() * 0.6, 255, cv.THRESH_BINARY)
    cv.imshow("surface-bin", surface)

    surface_fg = np.uint8(surface)
    unknown = cv.subtract(sure_bg, surface_fg)#未知局域
    ret, markers = cv.connectedComponents(surface_fg)#连通区域
    print(ret)

    # watershed transfrom  分水岭变换
    markers += 1
    markers[unknown == 255] = 0
    markers = cv.watershed(src, markers=markers)
    src[markers == -1] = [0, 0, 255]
    cv.imshow("result-image", src)


print("------------Python Opencv Tutorial!-------------")
# 读取图像，支持 bmp、jpg、png、tiff 等常用格式
src = cv.imread("F:/Projects/images/coins.png")
#创建窗口并显示图像
cv.namedWindow("input image",cv.WINDOW_AUTOSIZE)
cv.imshow("input image",src)   #显示原图
water_image()
cv.waitKey(0)
#释放窗口
cv.destroyAllWindows()

运行效果：

理论参考链接：https://blog.youkuaiyun.com/qq_31531635/article/details/73699734

                            https://www.cnblogs.com/wjy-lulu/p/7056466.html