from __future__ import print_function
from __future__ import division
import cv2 as cv
import numpy as np
# Create an image
r = 100
src = np.zeros((4*r, 4*r), dtype=np.uint8)
# Create a sequence of points to make a contour
vert = [None]*6
vert[0] = (3*r//2, int(1.34*r))
vert[1] = (1*r, 2*r)
vert[2] = (3*r//2, int(2.866*r))
vert[3] = (5*r//2, int(2.866*r))
vert[4] = (3*r, 2*r)
vert[5] = (5*r//2, int(1.34*r))
# Draw it in src
for i in range(6):cv.line(src, vert[i],  vert[(i+1)%6], ( 255 ), 3)
# Get the contours
_, contours, _ = cv.findContours(src, cv.RETR_TREE, cv.CHAIN_APPROX_SIMPLE)# Calculate the distances to the contour
raw_dist = np.empty(src.shape, dtype=np.float32)
for i in range(src.shape[0]):for j in range(src.shape[1]):raw_dist[i,j] = cv.pointPolygonTest(contours[0], (j,i), True)# 获取最大值即内接圆半径，中心点坐标
minVal, maxVal, _, maxDistPt = cv.minMaxLoc(raw_dist)
minVal = abs(minVal)
maxVal = abs(maxVal)# Depicting the  distances graphically
drawing = np.zeros((src.shape[0], src.shape[1], 3), dtype=np.uint8)
for i in range(src.shape[0]):for j in range(src.shape[1]):if raw_dist[i,j] < 0:drawing[i,j,0] = 255 - abs(raw_dist[i,j]) * 255 / minValelif raw_dist[i,j] > 0:drawing[i,j,2] = 255 - raw_dist[i,j] * 255 / maxValelse:drawing[i,j,0] = 255drawing[i,j,1] = 255drawing[i,j,2] = 255# max inner circle
cv.circle(drawing,maxDistPt, np.int(maxVal),(255,255,255), 1, cv.LINE_8, 0)
cv.imshow('Source', src)
cv.imshow('Distance and inscribed circle', drawing)cv.waitKey(0)
cv.destroyAllWindows()

#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main(void)
{const int r = 100;Mat src = Mat::zeros(Size(4 * r, 4 * r), CV_8U);vector<Point2f> vert(6);vert[0] = Point(3 * r / 2, static_cast<int>(1.34*r));vert[1] = Point(1 * r, 2 * r);vert[2] = Point(3 * r / 2, static_cast<int>(2.866*r));vert[3] = Point(5 * r / 2, static_cast<int>(2.866*r));vert[4] = Point(3 * r, 2 * r);vert[5] = Point(5 * r / 2, static_cast<int>(1.34*r));for (int i = 0; i < 6; i++){line(src, vert[i], vert[(i + 1) % 6], Scalar(255), 3);}// �����β���vector<vector<Point> > contours;findContours(src, contours, RETR_TREE, CHAIN_APPROX_SIMPLE);Mat raw_dist(src.size(), CV_32F);for (int i = 0; i < src.rows; i++){for (int j = 0; j < src.cols; j++){raw_dist.at<float>(i, j) = (float)pointPolygonTest(contours[0], Point2f((float)j, (float)i), true);}}// ��ȡ���� �Բ�뾶double minVal, maxVal;Point maxDistPt; // inscribed circle centerminMaxLoc(raw_dist, &minVal, &maxVal, NULL, &maxDistPt);minVal = abs(minVal);maxVal = abs(maxVal);Mat drawing = Mat::zeros(src.size(), CV_8UC3);for (int i = 0; i < src.rows; i++){for (int j = 0; j < src.cols; j++){if (raw_dist.at<float>(i, j) < 0){drawing.at<Vec3b>(i, j)[0] = (uchar)(255 - abs(raw_dist.at<float>(i, j)) * 255 / minVal);}else if (raw_dist.at<float>(i, j) > 0){drawing.at<Vec3b>(i, j)[2] = (uchar)(255 - raw_dist.at<float>(i, j) * 255 / maxVal);}else{drawing.at<Vec3b>(i, j)[0] = 255;drawing.at<Vec3b>(i, j)[1] = 255;drawing.at<Vec3b>(i, j)[2] = 255;}}}// draw max inner circlecircle(drawing, maxDistPt, (int)maxVal, Scalar(255, 255, 255));imshow("Source", src);imshow("Distance and inscribed circle", drawing);waitKey();return 0;
}