I am extremely new to computer vision and the opencv library.
I've done some googling around to try to find how to make a new image from a vector of Point2fs and haven't found any examples that work. I've seen
I'm working from this example and any help would be appreciated.
Code: I pass in occludedSquare.
resize(occludedSquare, occludedSquare, Size(0, 0), 0.5, 0.5);
cvtColor(occludedSquare, occludedSquare8u, CV_BGR2GRAY);
//convert to a binary image. pixel values greater than 200 turn to white. otherwize black
threshold(occludedSquare8u, thresh, 170.0, 255.0, THRESH_BINARY);
GaussianBlur(thresh, thresh, Size(7, 7), 2.0, 2.0);
//Do edge detection
Canny(thresh, edges, 45.0, 160.0, 3);
//Do straight line detection
HoughLines( edges, lines, 1.5, CV_PI/180, 50, 0, 0 );
cout << "Detected " << lines.size() << " lines." << endl;
// compute the intersection from the lines detected...
for( size_t i = 0; i < lines.size(); i++ )
for(size_t j = 0; j < lines.size(); j++)
Vec2f line1 = lines[i];
Vec2f line2 = lines[j];
if(acceptLinePair(line1, line2, CV_PI / 32))
Point2f intersection = computeIntersect(line1, line2);
if(intersections.size() > 0)
for(i = intersections.begin(); i != intersections.end(); ++i)
cout << "Intersection is " << i->x << ", " << i->y << endl;
circle(occludedSquare8u, *i, 1, Scalar(0, 255, 0), 3);
//Make new matrix bounded by the intersections
Should be as simple as
std::vector<cv::Point2f> points; cv::Mat image(points); //or cv::Mat image = cv::Mat(points)
The probably confusion is that a cv::Mat is an image
width*height*number of channels but it also a mathematical matrix ,
If you make a Mat from a vector of 'n' 2D points it will create a 2 column by 'n' rows matrix. You are passing this to a function which expects an image.
If you just have a scattered set of 2D points and want to display them as an image you need to make an empty cv::Mat of large enough size (whatever your maximum x,y point is) and then draw the dots using the drawing functions http://docs.opencv.org/doc/tutorials/core/basic_geometric_drawing/basic_geometric_drawing.html
If you just want to set the pixel values at those point coordinates search SO for opencv setting pixel values, there are lots of answers