如何使用cvFitLine Java

Question

我有以下代码:

´

        [...]cvCvtColor(subtraction, grayBuffer, CV_BGR2GRAY);
        cvThreshold(grayBuffer, grayBuffer, 127, 255, CV_THRESH_BINARY);
        cvFindContours(grayBuffer, mem, contours, Loader.sizeof(CvContour.class) , CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0));
        //cvFitLine(Mat(contours[0]),lines,2,0,0.01,0.01);
        cvFitLine(contours, CV_DIST_L2, 2, 0.01, 0.01, line);
        int lefty = (int)((int)(-line[2]*line[1]/line[0])+line[3]);
        int righty = (int) ((int)((grayBuffer.width()-line[2])*line[1]/line[0])+line[3]);
        line(grayBuffer.width()-1,0,righty,lefty); [...]´

，这给了我一个致命错误。

有人知道如何使用fitLine吗?

谢谢:)

Answer 1

下面是一个使用cvFitLine(为Processing语言编写，它提供setup()和exit()方法)的javacv程序:

import com.googlecode.javacv.*;
import com.googlecode.javacv.cpp.*;
import com.googlecode.javacpp.IntPointer;
final int numPoints = 10;
int pt2[] = new int[numPoints*2], x = 0, y = 1;
float testPar[] = new float[4];// to store the results
void setup() {
  for (int i = 0; i < numPoints; i++) {
    pt2[ i*2 ] = i * 5; pt2[ i*2 + 1 ] = i * 5;
  }
  opencv_core.CvMat point_mat = opencv_core.cvMat(1, numPoints, opencv_core.CV_32SC2, new IntPointer(pt2));
  opencv_imgproc.cvFitLine(point_mat, opencv_imgproc.CV_DIST_HUBER, 0, 0.01, 0.01,testPar);
  for (int i = 0; i < testPar.length; i++) 
    println("i: " + i + ", testPar: " + testPar[i]);
  exit(); 
}

输出:

i: 0, testPar: 0.70710677
i: 1, testPar: 0.70710677
i: 2, testPar: 22.5
i: 3, testPar: 22.5