javacv - JavaCV cvApproxPoly method call error

Question

Im working in JavaCV and im trying to detect rectangle skewed by perspective and fix the image to right perspective using 4 corners of a rectangle. I have this code:

CvSeq corners_seq = new CvSeq();
int count = 0;
for (int i = 0; i < table_lines.length; i++)
{
    for (int j = i + 1; j < table_lines.length; j++)
    {
        CvPoint pt = HelperClass.ComputeIntersection(table_lines[i][0],table_lines[i][1], table_lines[j][0],table_lines[j][1]);
        if (pt.x() >= 0 && pt.y() >= 0)
        {
             corners_seq.put(pt);
        }
    }
}
CvMemStorage corners_storage = cvCreateMemStorage(0);
CvSeq corners = cvApproxPoly(corners_seq, corners_seq.header_size(), corners_storage, CV_POLY_APPROX_DP, 8, 0);

And at cvApproxPoly i get error from native method:

Exception in thread "main" java.lang.RuntimeException: ..\..\..\src\opencv\modules\imgproc\src\utils.cpp:54: error: (-5) Input array is not a valid matrix at com.googlecode.javacv.cpp.opencv_imgproc.cvApproxPoly(Native Method)

What am i doing wrong? As i understand it, the input argument is Pointer to CvSeq

Answer 1

CvMemStorage 存储 = cvCreateMemStorage(0);

CvSeq cvSeq = cvCreateSeq(0, Loader.sizeof(CvContour.class), Loader.sizeof(CvSeq.class), storage);