Question

我试图用emgu 3.1

找到轮廓的凸包

似乎FindContours只接受vectorOfVectorOfPoints（不是pointsF）。但是，convexhull需要vectorOfPointF。我错了吗？如果我将轮廓更改为VectorOfVectorOfPointF，则在调用FindContours时会出现运行时错误。

如何将VectorOfPoint转换为VectorOfPointF？有没有更好的方法呢？

谢谢！

using (var contours = new VectorOfVectorOfPoint())
using (Mat hierachy = new Mat())
{

    CvInvoke.FindContours(img, contours, hierachy, Emgu.CV.CvEnum.RetrType.External, Emgu.CV.CvEnum.ChainApproxMethod.ChainApproxSimple, new Point());
            for (int i = 0; i < contours.Size; i++)
            {
                var contour = contours[i];
                var c = new VectorOfPointF();
                CvInvoke.ConvexHull(contour, c, false, true);
            }

Answer 1

似乎唯一的方法是从contours对象中的每个VectorOfPoint构造VectorOfPointF：

for (int i = 0; i < contours.Size; i++)
{
    var contour = contours[i];
    var vf = new PointF[vp.Size];
    for (int ii = 0; ii < contour.Size; ii++) vf[i] = new PointF(contour[ii].X, contour[ii].Y);
    VectorOfPointF vvf = new VectorOfPointF(vf);
    var c = new VectorOfPointF();
    CvInvoke.ConvexHull(vvf, c, false, true);
}

Answer 2

@Atresmo的答案的最新版本。我们可以将Point投射到PointF：

for (int i = 0; i < contours.Size; i++)
{
    var contour = contours[i];
    var vf = new PointF[contour.Size];
    for (int ii = 0; ii < contour.Size; ii++) vf[i] = contour[ii];
    VectorOfPointF vvf = new VectorOfPointF(vf);
    var c = new VectorOfPointF();
    CvInvoke.ConvexHull(vvf, c, false, true);
}

从VectorOfPoint转换为VectorOfPointF以获取Emgu中的轮廓

2 个答案: