围绕轮廓绘制边界框JavaCV

Question

我想知道如何使用JavaCV围绕轮廓绘制边界框。我知道像素的面积和中心点。我还找到了一种找到像素宽度的方法来找到距离。我觉得边界框比我正在做的更准确，可以找到像素宽度来找到距离。任何帮助都会很好，或者如果你知道另一种寻找距离的方法，那就太好了。谢谢

import org.bytedeco.javacpp.*;
import org.bytedeco.javacpp.opencv_core.CvMemStorage;
import org.bytedeco.javacpp.opencv_core.IplImage;
import org.bytedeco.javacpp.opencv_videoio.CvCapture;
import static org.bytedeco.javacpp.opencv_core.*;
import static org.bytedeco.javacpp.opencv_imgproc.*;
public class Webcam {
   public static void main(String[] args) throws Exception {
       CvCapture capture = opencv_videoio.cvCreateCameraCapture(0);
       IplImage img1, imghsv, imgbin;
       CvScalar minc = cvScalar(95,125,75,0), maxc = cvScalar(145,255,255,0);
       CvSeq contour1 = new CvSeq(), contour2;
       CvMemStorage storage = CvMemStorage.create();
       CvMoments moments = new CvMoments(Loader.sizeof(CvMoments.class));
       double areaMax = 1000, areaC = 0;
       double m01, m10, m_area, focal, width, obj_width, obj_height;
       double distance;
       //focal is (pixel width * distance in inches) / object width 
       focal = 144.4;
       //Real objects width in inches
       obj_width = 3.5;
     //Real objects height in inches
       obj_height = 3.5;
       int posX=0, posY=0;
       int cRad = 100;
       while(true)
       {
       img1 = opencv_videoio.cvQueryFrame(capture); 
       opencv_imgproc.cvSmooth(img1, img1, CV_MEDIAN, 13, 0, 0, 0);
       imgbin = IplImage.create(cvGetSize(img1), 8, 1);
       imghsv = IplImage.create(cvGetSize(img1), 8, 3);

       if(img1 == null) break;
       cvCvtColor(img1, imghsv, CV_BGR2HSV);
       cvInRangeS(imghsv, minc, maxc, imgbin);
       contour1 = new CvSeq();
       areaMax = 1000;
       cvFindContours(imgbin, storage, contour1, Loader.sizeof(CvContour.class), CV_RETR_LIST, CV_LINK_RUNS, cvPoint(0,0));
       contour2 = contour1;
       while(contour1 != null && !contour1.isNull())
       {
           areaC = cvContourArea(contour1, CV_WHOLE_SEQ, 1);
           if(areaC > areaMax)
           {
               areaMax = areaC;
           }
           contour1 = contour1.h_next();
       }
       while(contour2 != null && !contour2.isNull())
       {
           areaC = cvContourArea(contour2, CV_WHOLE_SEQ, 1);
           if(areaC < areaMax)
           {
               cvDrawContours(imgbin, contour2, CV_RGB(0,0,0),CV_RGB(0,0,0),0,CV_FILLED,8,cvPoint(0,0));
           }
           contour2 = contour2.h_next();
       }
       cvMoments(imgbin, moments, 1);
       m10 = cvGetSpatialMoment(moments, 1, 0);
       m01 = cvGetSpatialMoment(moments, 0, 1);
       m_area = cvGetCentralMoment(moments, 0, 0);
       posX = (int) (m10/m_area);
       posY = (int) (m01/m_area);
       if(posX > 0 && posY > 0)
       {
           cRad = (int) (100 / (5000/m_area));
           cvCircle(img1, cvPoint(posX, posY), 5, cvScalar(0,255,0,0), 9, 0, 0);
       }
       //Change numbers after m_area to size of object
       width =  java.lang.Math.sqrt((m_area/(obj_height*obj_width)));
       distance = (obj_width * focal) / width;
       cvFlip(img1, img1, 1);
       cvFlip(imgbin, imgbin , 1);
       opencv_highgui.cvShowImage("Color",img1);
       opencv_highgui.cvShowImage("CF",imgbin);
       char c = (char) opencv_highgui.cvWaitKey(15);
       if(c == 27) break;
       if(c == 'q')
       {
           System.out.print("Width in pixels ");
           System.out.println(width);
           System.out.print("Distance in inches ");
           System.out.println(distance);
       }
       }
   }
}

这就是我所拥有的，这就是我想要的。我能够找到所有的蓝色轮廓，并将背景变成黑色。我只想在蓝色像素周围绘制一个边界框，以帮助更好地找到与对象的距离，并确保我们正在跟踪正确的对象。

Answer 1

如果你想在轮廓周围绘制一个束框，只需使用：

Rect rect = opencv_imgproc.boundingRect(contour);
opencv_imgproc.rectangle(src, rect, Scalar.GREEN);