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opencv KMeans.cpp 学习

2017-02-19 13:46 218 查看
打算利用KMeans算法做一个聚类,将聚类后的数据进行分析。学习下KMeans API的使用,顺便学习下常见的一些函数的用法。
官方文档如下:
#include "opencv2/highgui.hpp"
#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include <iostream>
using namespace cv;
using namespace std;
// static void help()
// {
//     cout << "\nThis program demonstrates kmeans clustering.\n"
//             "It generates an image with random points, then assigns a random number of cluster\n"
//             "centers and uses kmeans to move those cluster centers to their representitive location\n"
//             "Call\n"
//             "./kmeans\n" << endl;
// }
int main(int /*argc*/, char** /*argv*/)
{
const int MAX_CLUSTERS = 5;
Scalar colorTab[] =
{
Scalar(0, 0, 255),
Scalar(0,255,0),
Scalar(255,100,100),
Scalar(255,0,255),
Scalar(0,255,255)
};
Mat img(500, 500, CV_8UC3);
RNG rng(12345);
for (;;)
{
int k, clusterCount = rng.uniform(2, MAX_CLUSTERS + 1);
int i, sampleCount = rng.uniform(1, 1001);
Mat points(sampleCount, 1, CV_32FC2), labels;
clusterCount = MIN(clusterCount, sampleCount);
Mat centers;
/* generate random sample from multigaussian distribution */
for (k = 0; k < clusterCount; k++)
{
Point center;
center.x = rng.uniform(0, img.cols);
center.y = rng.uniform(0, img.rows);
Mat pointChunk = points.rowRange(k*sampleCount / clusterCount,
k == clusterCount - 1 ? sampleCount :
(k + 1)*sampleCount / clusterCount);
rng.fill(pointChunk, RNG::NORMAL, Scalar(center.x, center.y), Scalar(img.cols*0.05, img.rows*0.05));
}
randShuffle(points, 1, &rng);
kmeans(points, clusterCount, labels,
TermCriteria(TermCriteria::EPS + TermCriteria::COUNT, 10, 1.0),
3, KMEANS_PP_CENTERS, centers);
img = Scalar::all(0);
for (i = 0; i < sampleCount; i++)
{
int clusterIdx = labels.at<int>(i);
Point ipt = points.at<Point2f>(i);
circle(img, ipt, 2, colorTab[clusterIdx], FILLED, LINE_AA);
}
imshow("clusters", img);
char key = (char)waitKey();
if (key == 27 || key == 'q' || key == 'Q') // 'ESC'
break;
}
return 0;
}


RNG 随机数产生器。
RNG::uniform() 产生单个服从均匀分布的随机数。
RNG::fill(
 (InputOutputArray mat,
  int distType,
  InputArray a,
  InputArray b,
  bool saturateRange =
false
 
 )
)将Mat填充以服从正态分布或者均匀分布的随机数(正态分布的均值为a,方差为b;均匀分布的边界为a b)
后续补充
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