OpenCV找到最大的轮廓?

时间:2011-09-29 02:11:16

标签: c++ opencv video image-recognition

我有一个图像,我在其上使用了cvFindContours() - 我将结果存储在imageContours中。然后我试图找到两个最大的轮廓并仅显示它们。但由于某种原因,它的显示方式超过2个轮廓。我的算法出了什么问题?感谢

编辑:哦,而且,在控制台中,我一直收到“错误”消息,如果没有任何选项是真的,我在下面编程。谁知道为什么?

cvFindContours (binMask, imageContoursMem, &imageContours, sizeof (CvContour), CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE); //find the contours in binMask, and store results in ImageContours

    //following conditions used to set f_handContour to the bigger contour for the first time, and s_handContour to the smaller contour for the first time
    if ( (cvContourArea (imageContours, CV_WHOLE_SEQ)) > (cvContourArea((imageContours -> h_next), CV_WHOLE_SEQ)))
    { //begin first contour bigger condition

        f_handContour = imageContours;
        s_handContour = (imageContours -> h_next);

    } //end second contour bigger condition

    else if ( (cvContourArea (imageContours, CV_WHOLE_SEQ)) < (cvContourArea((imageContours -> h_next), CV_WHOLE_SEQ)))
    { //begin second contour bigger condition

        f_handContour = (imageContours -> h_next);
        s_handContour = imageContours;

    } //begin second contour biggger condition

    else if  ( (cvContourArea (imageContours, CV_WHOLE_SEQ)) == (cvContourArea((imageContours -> h_next), CV_WHOLE_SEQ)))
    { //begin contours equal condition

        f_handContour = imageContours; //if contours equal assignment of contours doesn't matter
        s_handContour = (imageContours -> h_next);

    } //end contours equal condition

    else
    { //begin error condition

        cout<<"Error";

    } //end error condition

    while ((imageContours -> h_next) != NULL)
    { //start of biggest/second biggest contour recognition loop

        imageContours = (imageContours -> h_next);

        if ( cvContourArea (f_handContour, CV_WHOLE_SEQ) < cvContourArea (imageContours, CV_WHOLE_SEQ))
        { //start of next contour bigger than f_handContour condition

            s_handContour = f_handContour;
            f_handContour = imageContours;

        } //end start of next contour bigger than f_handContour condition

        else if ( cvContourArea (f_handContour, CV_WHOLE_SEQ) > cvContourArea (imageContours, CV_WHOLE_SEQ))
        { //start of next contour smaller than f_handContour condition

            if ( cvContourArea (s_handContour, CV_WHOLE_SEQ) < cvContourArea (imageContours, CV_WHOLE_SEQ))
            { //startof next contour bigger than s_handContour condition

              s_handContour = imageContours;

            } //end of next contour bigger than s_handContour condition

            else if ( cvContourArea (s_handContour, CV_WHOLE_SEQ) > cvContourArea (imageContours, CV_WHOLE_SEQ))
            { //start of next contour smaller than s_handContour condition

                //just pass on contour

            } //end of next contour smaller than s_handContour condition

            else if ( cvContourArea (s_handContour, CV_WHOLE_SEQ) == cvContourArea (imageContours, CV_WHOLE_SEQ))
            { //start of next contour equal to s_handContour condition

                //just pass on contour

            } // end of next contour equal to s_handContour condition

            else
            { //start of error condition

                cout<<"Error";

            } //end of error condition

        } //end of next contour smaller than f_handContour Condition

        else if ( cvContourArea (f_handContour, CV_WHOLE_SEQ) == cvContourArea (imageContours, CV_WHOLE_SEQ))
        { //start of next contour equal to f_handContour condition

            if ( cvContourArea (s_handContour, CV_WHOLE_SEQ) < cvContourArea (imageContours, CV_WHOLE_SEQ))
            { //startof next contour bigger than s_handContour condition

              s_handContour = imageContours;

            } //end of next contour bigger than s_handContour condition

            else
            { //start of error condition

                cout<<"Error";

            } //end of error condition

        } //end of next contour equal to f_handContour condition

        else
        { //start of error condition

            cout<<"Error";

        } //end of error condition

    } //end of biggest/second biggest contour recognition loop

    cvDrawContours (output, f_handContour, cvScalar (0,255,0), cvScalar (0,255,255), 1, 3,8, cvPoint (0,0)); //draws the first hand contour derived from binMask on ouput
    cvDrawContours (output, s_handContour, cvScalar (0,255,0), cvScalar (0,255,255), 1, 3,8, cvPoint (0,0)); //draws the second hand contour derived from binMask on ouput

1 个答案:

答案 0 :(得分:1)

CV_RETR_EXTERNAL仅检索极端外轮廓。 对于您的算法,您应该使用CV_RETR_LIST。 尝试使用max_level作为cvDrawContours函数的值0,因为值1绘制当前轮廓以及与它在同一级别上的所有其他轮廓。 你也可以很好地优化你的条件(这有点混乱),并且还将区域存储在一些局部变量中,以免过多地调用cvContourArea。