OpenCV——运用于pixels war游戏
// The "Square Detector" program. // It loads several images sequentially and tries to find squares in // each image #include "opencv2/core/core.hpp" #include "opencv2/imgproc/imgproc.hpp" #include "opencv2/highgui/highgui.hpp" #include <iostream> #include <math.h> #include <string.h> #include <vector> using namespace cv; using namespace std; static void help() { cout << "\nA program using pyramid scaling, Canny, contours, contour simpification and\n" "memory storage (it's got it all folks) to find\n" "squares in a list of images pic1-6.png\n" "Returns sequence of squares detected on the image.\n" "the sequence is stored in the specified memory storage\n" "Call:\n" "./squares\n" "Using OpenCV version %s\n" << CV_VERSION << "\n" << endl; } int thresh = 50, N = 11; const char* wndname = "Square Detection Demo"; // helper function: // finds a cosine of angle between vectors // from pt0->pt1 and from pt0->pt2 static double angle( Point pt1, Point pt2, Point pt0 ) { 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); } // returns sequence of squares detected on the image. // the sequence is stored in the specified memory storage static void findSquares( const Mat& image, vector<vector<Point> >& squares ) { squares.clear(); Mat pyr, timg, gray0(image.size(), CV_8U), gray; // down-scale and upscale the image to filter out the noise pyrDown(image, pyr, Size(image.cols/2, image.rows/2)); pyrUp(pyr, timg, image.size()); vector<vector<Point> > contours; // find squares in every color plane of the image for( int c = 0; c < 3; c++ ) { int ch[] = {c, 0}; mixChannels(&timg, 1, &gray0, 1, ch, 1);//分别将r,g,b三个通道的内容拷贝到gray0通道 // try several threshold levels for( int l = 0; l < N; l++ ) { // hack: use Canny instead of zero threshold level. // Canny helps to catch squares with gradient shading if( l == 0 ) { // apply Canny. Take the upper threshold from slider // and set the lower to 0 (which forces edges merging) Canny(gray0, gray, 5 , thresh, 5); // dilate canny output to remove potential // holes between edge segments dilate(gray, gray, Mat(), Point(-1,-1)); } else { // apply threshold if l!=0: // tgray(x,y) = gray(x,y) < (l+1)*255/N ? 255 : 0 gray = gray0 >= (l+1)*255/N; } // find contours and store them all as a list //imshow("temp",gray); findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE); vector<Point> approx; // test each contour for( size_t i = 0; i < contours.size(); i++ ) { // approximate contour with accuracy proportional // to the contour perimeter approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true); // square contours should have 4 vertices after approximation // relatively large area (to filter out noisy contours) // and be convex. // Note: absolute value of an area is used because // area may be positive or negative - in accordance with the // contour orientation int a=approx.size(); int b=abs(contourArea(Mat(approx))); bool c=isContourConvex(Mat(approx)); if( approx.size() == 4 && fabs(contourArea(Mat(approx))) >5 &&fabs(contourArea(Mat(approx)))<10000&& isContourConvex(Mat(approx)) ) { double maxCosine = 0; for( int j = 2; j < 5; j++ ) { // find the maximum cosine of the angle between joint edges double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1])); maxCosine = MAX(maxCosine, cosine); } // if cosines of all angles are small // (all angles are ~90 degree) then write quandrange // vertices to resultant sequence if( maxCosine < 0.5 ) squares.push_back(approx); } } } } } // the function draws all the squares in the image static void drawSquares( Mat& image, const vector<vector<Point> >& squares ) { //vector<Point> pointsToTest; vector<int> valueOfChannel0/*,valueOfChannel1,valueOfChannel2*/; int differentPoint,normalPoint,tempPoint=0; bool setDifferentPoint=0; //bool setNormalPoint=0; for( size_t i = 0; i < squares.size(); i++ ) { const Point* p = &squares[i][0]; int n = (int)squares[i].size(); ////////////////////////////////////////////////////////////////////////////////////////////// Point middlePoint((squares[i][0].x+squares[i][3].x)/2,(squares[i][0].y+squares[i][1].y)/2); //pointsToTest.push_back(middlePoint); tempPoint=(int)image.at<Vec3b>(middlePoint.y,middlePoint.x)[0]; //cout<<tempPoint<<endl; if (0==i) { normalPoint=tempPoint; polylines(image, &p, &n, 1, true, Scalar(255,0,255), 1, CV_AA); } else { if (tempPoint!=normalPoint) { if (!setDifferentPoint) { differentPoint=tempPoint; setDifferentPoint=1; } polylines(image, &p, &n, 1, true, Scalar(0,0,255), 1, CV_AA); } else { polylines(image, &p, &n, 1, true, Scalar(255,0,255), 1, CV_AA); } } } imshow(wndname, image); } int main(int /*argc*/, char** /*argv*/) { static const char* names[] = { "Image 001.png", "Image 002.png", "Image 003.png", "Image 004.png", "Image 005.png", "Image 006.png","Image 007.png",0 }; help(); namedWindow( wndname, 1 ); vector<vector<Point> > squares; for( int i = 0; names[i] != 0; i++ ) { Mat image = imread(names[i], 1); if( image.empty() ) { cout << "Couldn't load " << names[i] << endl; continue; } findSquares(image, squares); drawSquares(image, squares); int c = waitKey(); if( (char)c == 27 ) break; remove("Image 001.png"); } return 0; }