There are no errors while compiling here in the image i need to draw a contour over only a rectangular subpixel image but contours are drawn all over the image and rectangle,moreover subpixel image is not cropped.pls help me with a soln Mat src; Mat src_gray; int thresh = 100; int max_thresh = 255; RNG rng(12345);
/// Function header void thresh_callback(int, void* );
/* @function main */ int main( int argc, char* argv ) { /// Load source image and convert it to gray src = imread( argv[1], 1 );
/// Convert image to gray and blur it cvtColor( src, src_gray, CV_BGR2GRAY ); blur( src_gray, src_gray, Size(3,3) );
/// Create Window char* source_window = "Source"; namedWindow( source_window, CV_WINDOW_AUTOSIZE ); imshow( source_window, src );
createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback ); thresh_callback( 0, 0 ); // rect is the RotatedRect (I got it from a contour...) RotatedRect rect; // matrices we'll use Mat M, rotated, cropped; // get angle and size from the bounding box float angle = rect.angle; Size rect_size = rect.size; if (rect.angle < -45.) { angle += 90.0; swap(rect_size.width, rect_size.height); } // get the rotation matrix M = getRotationMatrix2D(rect.center, angle, 1.0); // perform the affine transformation warpAffine(src, rotated, M, src.size(), INTER_CUBIC); // crop the resulting image getRectSubPix(rotated, rect_size, rect.center, cropped); waitKey(0); return(0); }
/* @function thresh_callback */ void thresh_callback(int, void ) { Mat threshold_output; vector<vector<point> > contours; vector<vec4i> hierarchy;
/// Detect edges using Threshold threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY ); /// Find contours findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
/// Approximate contours to polygons + get bounding rects and circles vector<vector<point> > contours_poly( contours.size() ); vector<rect> boundRect( contours.size() ); vector<point2f>center( contours.size() ); vector<float>radius( contours.size() );
for( int i = 0; i < contours.size(); i++ ) { approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true ); boundRect[i] = boundingRect( Mat(contours_poly[i]) ); minEnclosingCircle( (Mat)contours_poly[i], center[i], radius[i] ); }
/// Draw polygonal contour + bonding rects + circles Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 ); for( int i = 0; i< contours.size(); i++ ) { Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) ); drawContours( drawing, contours_poly, i, color, 1, 8, vector<vec4i>(), 0, Point() ); rectangle( drawing, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 ); circle( drawing, center[i], (int)radius[i], color, 2, 8, 0 ); }
/// Show in a window namedWindow( "Contours", CV_WINDOW_AUTOSIZE ); imshow( "Contours", drawing ); }
