openCV no matching function fillPoly

问题

I am trying to implement this answer, but I am getting always error. Please help.

My code:

cv::Point corners[1][6];

for (unsigned long j = startIndex; j < startIndex+6; j++) {
  int x = shape.part(j).x(); 
  int y = shape.part(j).y();

  corners[0][j-startIndex] = Point(x, y);
}
const Point* corner_list[1] = {corners[0]};

cv::Mat mask(image.rows, image.cols, CV_8UC2);
cv::fillPoly(mask, corner_list, 6, 1, cv::Scalar(255), 8);
cv::Mat result(image.size(), image.type(), cv::Scalar(0,0,0));
image.copyTo(result, mask);

Here is my error:

jni/jni_detections/jni_face_det.cpp:121:5: error: no matching function for call to 'fillPoly'
    cv::fillPoly( mask, corner_list, num_points, num_polygons, cv::Scalar( 255, 255, 255 ),  line_type);
    ^~~~~~~~~~~~ 
/home/feli/Development/android/test/dlib/dlib-android/third_party/opencv/jni/include/opencv2/imgproc.hpp:3987:17: note: 
      candidate function not viable: no known conversion from 'int' to 'const int *' for 3rd argument; take the address of
      the argument with & CV_EXPORTS void fillPoly(Mat& img, const Point** pts,
                                          ^ 
/home/feli/Development/android/test/dlib/dlib-android/third_party/opencv/jni/include/opencv2/imgproc.hpp:4005:19: note: 
      candidate function not viable: no known conversion from 'const Point *[1]' to 'const cv::_InputArray' for 2nd argument 
CV_EXPORTS_W void fillPoly(InputOutputArray img, InputArrayOfArrays pts,
                  ^

My OpenCV version is 3.1.0

回答1:

I needed to pass the numPoints parameter's pointer like this:

int num_points = 6;
cv::fillPoly(mask, corner_list, &num_points, 1, cv::Scalar(255), 8);

Thanks @Tim Sweet

回答2:

Looks like you need to change

cv::Scalar(255)

cv::Scalar(255,255,255)

来源：https://stackoverflow.com/questions/45441744/opencv-no-matching-function-fillpoly

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