CODEWITHSUNDEEP
c++opencv
Sridhar Thiagarajan
Sridhar Thiagarajan

Reputation: 580

Drawing minarea rectangle for convex hull

Hi i've been trying to recognize hand signatures(numbers) using OpenCV.i am encountering a problem where 1 and 2 show the same number of convexity defects. One way i thought i could rectify this was by drawing a Minbounding rectangle..and find the ratio of the area of the convex hull to that of the bounding rectangle. However im not aware how to do this.

vector<vector<Point>> hull;

The index of the hull i am interested in is say k;

How do i draw a rotated rectangle for this convex hull?

Upvotes: 0

Views: 1002

Answers (1)

Miki
Miki

Reputation: 41765

// Assuming 
// vector<vector<Point>> hull;
// Mat3b frame; 

if((k >= 0) && (k < hull.size()) && (!hull[k].empty()))
{
    RotatedRect rotated = minAreaRect(hull[k]);
    Point2f rect_points[4]; 
    rotated.points( rect_points );
    for( int j = 0; j < 4; j++ ) {
       line( frame, rect_points[j], rect_points[(j+1)%4], Scalar(255,0,0), 1, 8 );
    }
}

Upvotes: 1

Related Questions