dc/d48/tutorial_point_polygon_test.html

 #include "opencv2/highgui/highgui.hpp"

 #include "opencv2/imgproc/imgproc.hpp"

 #include <iostream>

 #include <stdio.h>

 #include <stdlib.h>


 using namespace cv;

 using namespace std;


 int main( void )

 {

  const int r = 100;

  Mat src = Mat::zeros( Size( 4*r, 4*r ), CV_8UC1 );


  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 j = 0; j < 6; j++ )

  { line( src, vert[j], vert[(j+1)%6], Scalar( 255 ), 3, 8 ); }


  vector<vector<Point> > contours; vector<Vec4i> hierarchy;

  Mat src_copy = src.clone();


  findContours( src_copy, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE);


  Mat raw_dist( src.size(), CV_32FC1 );


  for( int j = 0; j < src.rows; j++ )

  { for( int i = 0; i < src.cols; i++ )

  { raw_dist.at<float>(j,i) = (float)pointPolygonTest( contours[0], Point2f((float)i,(float)j), true ); }

  }


  double minVal; double maxVal;

  minMaxLoc( raw_dist, &minVal, &maxVal, 0, 0, Mat() );

  minVal = abs(minVal); maxVal = abs(maxVal);


  Mat drawing = Mat::zeros( src.size(), CV_8UC3 );


  for( int j = 0; j < src.rows; j++ )

  { for( int i = 0; i < src.cols; i++ )

  {

  if( raw_dist.at<float>(j,i) < 0 )

  { drawing.at<Vec3b>(j,i)[0] = (uchar)(255 - abs(raw_dist.at<float>(j,i))*255/minVal); }

  else if( raw_dist.at<float>(j,i) > 0 )

  { drawing.at<Vec3b>(j,i)[2] = (uchar)(255 - raw_dist.at<float>(j,i)*255/maxVal); }

  else

  { drawing.at<Vec3b>(j,i)[0] = 255; drawing.at<Vec3b>(j,i)[1] = 255; drawing.at<Vec3b>(j,i)[2] = 255; }

  }

  }


  const char* source_window = "Source";

  namedWindow( source_window, WINDOW_AUTOSIZE );

  imshow( source_window, src );

  namedWindow( "Distance", WINDOW_AUTOSIZE );

  imshow( "Distance", drawing );


  waitKey(0);

  return(0);

 }

cv::Scalar
Scalar_< double > Scalar
Definition: types.hpp:597

cv::minMaxLoc
void minMaxLoc(InputArray src, double *minVal, double *maxVal=0, Point *minLoc=0, Point *maxLoc=0, InputArray mask=noArray())
Finds the global minimum and maximum in an array.

highgui.hpp

cv::Mat::rows
int rows
the number of rows and columns or (-1, -1) when the matrix has more than 2 dimensions ...
Definition: mat.hpp:1865

cv::Mat::zeros
static MatExpr zeros(int rows, int cols, int type)
Returns a zero array of the specified size and type.

cv::imshow
void imshow(const String &winname, InputArray mat)
Displays an image in the specified window.

CV_8UC1
#define CV_8UC1
Definition: cvdef.h:116

cv::Point_< float >

cv::RETR_TREE
Definition: imgproc.hpp:409

cv::Vec
Template class for short numerical vectors, a partial case of Matx.
Definition: matx.hpp:300

cv::Mat::cols
int cols
Definition: mat.hpp:1865

cv::line
void line(InputOutputArray img, Point pt1, Point pt2, const Scalar &color, int thickness=1, int lineType=LINE_8, int shift=0)
Draws a line segment connecting two points.

cv::Mat::clone
Mat clone() const
Creates a full copy of the array and the underlying data.

imgproc.hpp

cv::Mat::size
MatSize size
Definition: mat.hpp:1882

uchar
unsigned char uchar
Definition: defs.h:284

cv::namedWindow
void namedWindow(const String &winname, int flags=WINDOW_AUTOSIZE)
Creates a window.

cv::Size
Size2i Size
Definition: types.hpp:308

i
for i
Definition: modelConvert.m:63

CV_32FC1
#define CV_32FC1
Definition: cvdef.h:146

CV_8UC3
#define CV_8UC3
Definition: cvdef.h:118

cv::CHAIN_APPROX_SIMPLE
Definition: imgproc.hpp:421

cv::WINDOW_AUTOSIZE
Definition: highgui.hpp:138

cvflann::abs
T abs(T x)
Definition: dist.h:58

cv::pointPolygonTest
double pointPolygonTest(InputArray contour, Point2f pt, bool measureDist)
Performs a point-in-contour test.

cv::findContours
void findContours(InputOutputArray image, OutputArrayOfArrays contours, OutputArray hierarchy, int mode, int method, Point offset=Point())
Finds contours in a binary image.

main
int main(int argc, const char *argv[])
Definition: facerec_demo.cpp:67

cv::Mat
n-dimensional dense array class
Definition: mat.hpp:726

cv::Mat::at
_Tp & at(int i0=0)
Returns a reference to the specified array element.

cv::Point
Point2i Point
Definition: types.hpp:181

cv::waitKey
int waitKey(int delay=0)
Waits for a pressed key.