c# - 使用 OpenCvSharp 绘制矩形

Question

我正在尝试在其上实时绘制视频中检测到的面孔，但我似乎无法让它工作

var haarcascade = new CascadeClassifier("C:/Users/NotMyName/Desktop/haar/haarcascade_frontalface_alt2.xml");
using (Window window = new Window("capture"))
using (Mat image = new Mat())//Image Buffer
{
    while (true)
    {
        Video.Read(image);
        var gray = image.CvtColor(ColorConversionCodes.RGB2GRAY);
        OpenCvSharp.Rect[] faces = haarcascade.DetectMultiScale(gray, 1.08, 2, HaarDetectionTypes.ScaleImage, new OpenCvSharp.Size(30,30));
        foreach (Rect i in faces)
        {
            Cv2.Rectangle(image, (faces[i].BottomRight.X, faces[i].BottomRight.Y), (faces[i].TopLeft.X, faces[i].TopLeft.Y), 255, 1);
        }

但是，编译器只是吐出错误。将 faces 数组直接传递给函数也不起作用。错误消息是（翻译自德语）。

错误 CS0029 类型“OpenCvSharp.Rect”无法转换为“int”

Answer 1

我认为正确的方法应该是：

...
foreach (Rect i in faces)
{
    Cv2.Rectangle(image, new Point(i.BottomRight.X, i.BottomRight.Y), new Point(i.TopLeft.X, i.TopLeft.Y), 255, 1);
}
....

iforeach 内的局部变量对 current 的引用Rect。

Cv2.Rectangle方法接受OpenCvSharp.Point.

Answer 2

您可以直接使用Rect变量：

foreach (Rect r in faces)
    Cv2.Rectangle(image, (r.BottomRight.X, r.BottomRight.Y), (r.TopLeft.X, r.TopLeft.Y), 255, 1);

或使用int如下：

foreach (int i = 0; i < faces.Length; i++)
    Cv2.Rectangle(image, (faces[i].BottomRight.X, faces[i].BottomRight.Y), (faces[i].TopLeft.X, faces[i].TopLeft.Y), 255, 1);