//转为 bitmap：
Bitmap map = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(mat);
            process_pictureBox.Image = map;
//Image img 转为Mat
Bitmap bitmap = new Bitmap(img);//Image img
            OpenCvSharp.Mat mat = OpenCvSharp.Extensions.BitmapConverter.ToMat(bitmap);//用

//bitmap转换为mat
C#中Bitmap 与 Image 之间的转换
Image img = pictureBox1.Image;
Bitmap map = new Bitmap(img);

//而Bitmap直接可以赋值 给 Image 对象

Image img = Bitmap;复制