A program using pyramid scaling, Canny, contours and contour simplification to find squares in the input image.
#include <iostream>
int thresh = 50, N = 11;
const char* wndname = "Square Detection Demo";
{
double dx1 = pt1.
x - pt0.
x;
double dy1 = pt1.
y - pt0.
y;
double dx2 = pt2.
x - pt0.
x;
double dy2 = pt2.
y - pt0.
y;
return (dx1*dx2 + dy1*dy2)/
sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}
static void findSquares(
const UMat& image, vector<vector<Point> >& squares )
{
squares.clear();
vector<vector<Point> > contours;
for( int c = 0; c < 3; c++ )
{
int ch[] = {c, 0};
for( int l = 0; l < N; l++ )
{
if( l == 0 )
{
Canny(gray0, gray, 0, thresh, 5);
}
else
{
}
vector<Point> approx;
for( size_t i = 0; i < contours.size(); i++ )
{
if( approx.size() == 4 &&
{
double maxCosine = 0;
for( int j = 2; j < 5; j++ )
{
double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
maxCosine =
MAX(maxCosine, cosine);
}
if( maxCosine < 0.3 )
squares.push_back(approx);
}
}
}
}
}
static void drawSquares(
UMat& _image,
const vector<vector<Point> >& squares )
{
for( size_t i = 0; i < squares.size(); i++ )
{
const Point* p = &squares[i][0];
int n = (int)squares[i].size();
}
}
static UMat drawSquaresBoth(
const UMat& image,
const vector<vector<Point> >& sqs)
{
drawSquares(imgToShow, sqs);
return imgToShow;
}
int main(int argc, char** argv)
{
const char* keys =
"{ i input | ../data/pic1.png | specify input image }"
"{ o output | squares_output.jpg | specify output save path}"
"{ h help | | print help message }"
"{ m cpu_mode | | run without OpenCL }";
{
cout << "Usage : " << argv[0] << " [options]" << endl;
cout << "Available options:" << endl;
return EXIT_SUCCESS;
}
{
cout << "OpenCL was disabled" << endl;
}
string outfile = cmd.
get<
string>(
"o");
int iterations = 10;
vector<vector<Point> > squares;
{
cout << "Couldn't load " << inputName << endl;
return EXIT_FAILURE;
}
int j = iterations;
cout << "warming up ..." << endl;
findSquares(image, squares);
do
{
findSquares(image, squares);
cout << "run loop: " << j << endl;
}
while(--j);
cout <<
"average time: " << 1000.0f * (double)t_cpp /
getTickFrequency() / iterations <<
"ms" << endl;
UMat result = drawSquaresBoth(image, squares);
return EXIT_SUCCESS;
}