c# OpenCV 不同尺寸图片叠加

using OpenCvSharp;

            Mat matBackground = new Mat(@"d:\bg.jpeg",ImreadModes.AnyColor);
            Mat matBoy = new Mat(@"d:\人像\10岁.jpg");
            Rect rect = new Rect(10, 20, matBoy.Width, matBoy.Height);
            Mat matRectInBackground = new Mat(matBackground, rect);
            matBoy.CopyTo(matRectInBackground);
            Cv2.ImShow("Merge", matBackground);
            Cv2.WaitKey();
            Console.WriteLine("Merged");