opencv3.1.0+vs2015——基于距离变换与分水岭的图像分割

API


代码如下所示：

#include
#include
using namespace std;
using namespace cv;
int main(int argc, char** argv)
{
	Mat src;
	src = imread("D:/studytest/pk.bmp");
	if (src.empty())
	{
		printf("could not load image...\n");
		return -1;
	}
	namedWindow("input image", CV_WINDOW_AUTOSIZE);
	imshow("input image", src);
	//1.change background 将背景转换为黑色
	for (int row = 0; row < src.rows; row++)
	{
		for(int col = 0; col < src.cols; col++)
		{
			if(src.at(row,col)==Vec3b(255,255,255))
			{
				src.at(row, col)[0] = 0;
				src.at(row, col)[1] = 0;
				src.at(row, col)[2] = 0;
			}
		}
	}
	namedWindow("black background", CV_WINDOW_AUTOSIZE);
	imshow("black background", src);
	//2.sharpen锐化提高对比度
	Mat kernel = (Mat_(3, 3) << 1, 1, 1, 1, -8, 1, 1, 1, 1);
	Mat imgLaplance;
	Mat sharpenImg = src;
	filter2D(src, imgLaplance, CV_32F, kernel, Point(-1, -1), 0, BORDER_DEFAULT);
	src.convertTo(sharpenImg, CV_32F);
	Mat resultImg = sharpenImg - imgLaplance;
	resultImg.convertTo(resultImg, CV_8UC3);
	imgLaplance.convertTo(imgLaplance, CV_8UC3);
	imshow("锐化后的图像sharpen_image", resultImg);
	//变换为二值图像
	Mat binImg;
	cvtColor(src, resultImg, CV_BGR2GRAY);
	threshold(resultImg, binImg, 40, 255, THRESH_BINARY | THRESH_OTSU);
	imshow("锐化后转二值的binImg", binImg);
	//距离变换
	Mat distImg;
	distanceTransform(binImg, distImg, DIST_L1, 3, 5);
	normalize(distImg, distImg, 0, 1, NORM_MINMAX);
	imshow("距离变换后的distImg", distImg);
	//距离变换结果二值化
	threshold(distImg, distImg, 0.4, 1, THRESH_BINARY);
	imshow("distImgtobin", distImg);
	//腐蚀
	Mat k1 = Mat::ones(13, 13, CV_8UC1);
	erode(distImg, distImg, k1, Point(-1, -1));
	imshow("腐蚀后的distImg", distImg);
	//markers找轮廓
	Mat dist_8u;
	distImg.convertTo(dist_8u, CV_8U);
	vector> contours;
	findContours(dist_8u, contours, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE, Point(0, 0));
	//create makers 画轮廓markers标记
	Mat markers = Mat::zeros(src.size(), CV_32SC1);
	for (size_t i = 0; i < contours.size(); i++)
		drawContours(markers, contours, static_cast(i), Scalar::all(static_cast(i) + 1),-1);
	circle(markers, Point(5, 5), 3, Scalar(255, 255, 255), -1);
	//imshow("my markers", markers*1000);
	//perform watershed
	watershed(src, markers);
	Mat mark = Mat::zeros(markers.size(), CV_8UC1);
	markers.convertTo(mark, CV_8UC1);
	bitwise_not(mark, mark, Mat());
	imshow("watershed image", mark);
	// 分配不同颜色
	vector colors;
	for (size_t i = 0; i < contours.size(); i++) {
		int r = theRNG().uniform(0, 255);
		int g = theRNG().uniform(0, 255);
		int b = theRNG().uniform(0, 255);
		colors.push_back(Vec3b((uchar)b, (uchar)g, (uchar)r));
	}
	// 填充颜色
	Mat dst = Mat::zeros(markers.size(), CV_8UC3);
	for (int row = 0; row < markers.rows; row++) {
		for (int col = 0; col < markers.cols; col++) {
			int index = markers.at(row, col);

			if (index > 0 && index <= static_cast(contours.size())) {
				dst.at(row, col) = colors[index - 1];

			}
			else {
				dst.at(row, col) = Vec3b(0, 0, 0);
			}
		}
	}
	imshow("Final Result", dst);
	waitKey(0);
	return 0;
}

结果如下图所示：