//引用 OpenCvSharp4.Extensions

        public static Bitmap ToBitmap(BitmapSource m)
        {
            System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(m.PixelWidth, m.PixelHeight, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
 
            System.Drawing.Imaging.BitmapData data = bmp.LockBits(
            new System.Drawing.Rectangle(System.Drawing.Point.Empty, bmp.Size), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
 
            m.CopyPixels(Int32Rect.Empty, data.Scan0, data.Height * data.Stride, data.Stride); bmp.UnlockBits(data);
 
            return bmp;
        }


//Bitmap转BitmapSource
Bitmap map = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(showImg); 


        public static BitmapSource GetImageSouce(Bitmap bitmap)
        {
            BitmapSource img;
            IntPtr hBitmap;
 
            hBitmap = bitmap.GetHbitmap();
            img = Imaging.CreateBitmapSourceFromHBitmap(
                hBitmap,
                IntPtr.Zero,
                Int32Rect.Empty,
                BitmapSizeOptions.FromEmptyOptions());
            return img;
        }

//paddleocr中需要传入3通道或1通道的mat，此时要用CV2.cvtColor进行转换

src = OpenCvSharp.Extensions.BitmapConverter.ToMat(bitmap);//bitmap转mat
Cv2.CvtColor(src, src, ColorConversionCodes.RGBA2RGB);//mat转三通道mat