Opencv 轮廓不是很好

我试着在我的图像中勾勒出形状的轮廓

以下是我的步骤：

灰度

模糊

索贝尔

找到轮廓线

代码如下：

 void detect_features ( string &path ){

            std::cout << "detection\n";
            Mat image, src;
            int ddepth = CV_16S;

            image = imread( path, IMREAD_GRAYSCALE ); // Load an image

            // Remove noise by blurring with a Gaussian filter ( kernel size = 3 )
            GaussianBlur( image, src, Size( 3, 3 ), 0, 0, BORDER_DEFAULT );

            // ![sobel]
            /// Generate grad_x and grad_y
            Mat grad_x, abs_grad_x;
            Mat grad_y, abs_grad_y;

            Sobel( src, grad_x, ddepth, 1, 0 );
            Sobel( src, grad_y, ddepth, 0, 1 );
            convertScaleAbs( grad_x, abs_grad_x );
            convertScaleAbs( grad_y, abs_grad_y );

            addWeighted( abs_grad_x, 1, abs_grad_y, 1, 0, final );

    }

无效检测功能（字符串和路径）{
标准：：cout
        void shapes_detection (){
            std::cout << "shape\n";
            vector <vector <Point> > contours;

            findContours( final, contours, RETR_TREE, CHAIN_APPROX_NONE );

              drawContours( final, contours, -1, 100, 2 );
              string pj = "out_shapes.jpg";
              write_final_img( pj );

              return;