如何在检测到面部opencv后展开矩形

Question

我编写代码,我想要如何在检测到面部之后将矩形扩展 到人的头部和颈部

    #include <opencv2/imgproc/imgproc.hpp>  //this code detetced faces ///
    #include <opencv2/objdetect/objdetect.hpp>///////////
    #include <opencv2/highgui/highgui.hpp>
     ////////////////////
    using namespace cv;
    using namespace std;

    int main()
    {

        CascadeClassifier cascade;

        if (!cascade.load("haarcascade_frontalface_alt2.xml"))  //load harcascade xml
            return -1;

         Mat src = imread("11.jpg");  //read image 

        if (src.empty())
            return -1;
    cv::resize(src,src,cv::Size(600,600));  resize image 
        Mat gray;
        cvtColor(src, gray, CV_BGR2GRAY);
        equalizeHist(gray, gray);

        vector<Rect> faces;
        cascade.detectMultiScale(gray, faces, 1.2, 3,0,Size(30,30));

        for (size_t i = 0; i < faces.size(); i++)
        {
     /////////////////////////////
            Rect r = faces[i];
    //////////////////////////////       

              Mat faceROI = gray( faces[i] );
          int x = faces[i].x;
          int y = faces[i].y;
          int h =0.3*y+faces[i].height;
          int w = faces[i].width;
          printf("Orig dimensions after h * w crop 1: %dx%d\n",h,w);
            printf("Orig dimensions after  x* y crop 2: %dx%d\n",x,y);

           rectangle(src,Point (x,y),Point(x + w,y +h),Scalar(255,0,255),1,4,0);
             imshow("mmmmmmmmmmm.jpg",src );  //show image in windows 
        }
    ///////////////////////////////

        waitKey(0);

        return 0;
    }

Answer 1

要展开OpenCV面矩形,您还可以使用下面的运算符(1)来进行cv::Rect类

//expanding or shrinking a rectangle by a certain amount
cv::Rect += cv::Size
//shifting a rectangle by a certain offset
cv::Rect -= cv::Point

将面部矩形扩展10%的示例将是

cv::Size deltaSize( faces[i].width * 0.1f, faces[i].height * 0.1f ); // 0.1f = 10/100
cv::Point offset( deltaSize.width/2, deltaSize.height/2);
faces[i] += deltaSize;
faces[i] -= offset;

Answer 2

您需要调整高度并适当地开始y坐标.

简而言之,我觉得箱子的两侧(顶部和底部)的高度应该增加0.3倍.所以我0.3*h从中减去y并添加0.3*2*h(即0.6*h)h.

这只是我的粗略计算.对于微调,您可以针对不同的面进行分析,并提出最适合您目的的测量.

这是更改的代码:

int x = faces[i].x;
int h_temp = faces[i].height;    // storing original height
int y = faces[i].y - h_temp*0.3; // y is reduced by 0.3*h
int w = faces[i].width;
int h = h_temp*1.6;              // height is increases by 60%

以下是我得到的结果.绿色显示原始我得到.蓝色是修改过的:

请记住,您想要选择多少,取决于您.调整以上值以获得所需结果.