WPF call graphic draw functions via bitmap converting to bitmapimage

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using static System.Net.Mime.MediaTypeNames;

namespace WpfApp78
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            Render();
            //Render2();
        }

        private BitmapImage GenerateBMIFromBitmap(Bitmap bmp)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                ms.Position = 0;
                var bmi = new BitmapImage();
                bmi.BeginInit();
                bmi.StreamSource = ms;
                bmi.CacheOption = BitmapCacheOption.OnLoad;
                bmi.EndInit();
                if (bmi.CanFreeze)
                {
                    bmi.Freeze();
                }
                return bmi;
            }
        }

        private void Render2()
        {
            using (var bmp = new Bitmap((int)this.ActualWidth, (int)this.ActualHeight))
            {
                using (Graphics g = Graphics.FromImage(bmp))
                {
                    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
                    g.Clear(System.Drawing.Color.Navy);
                    System.Drawing.Image image = System.Drawing.Image.FromFile(@"../../Images/1.jpg");
                    g.DrawImage(image, new System.Drawing.Rectangle(0, 0, (int)this.ActualWidth, (int)this.ActualHeight));
                    this.Background = new ImageBrush(GenerateBMIFromBitmap(bmp));
                }
            }
        }

        Random rand= new Random();
        private void Render()
        {
            using (var bmp = new Bitmap((int)this.ActualWidth, (int)this.ActualHeight))
            using (var gfx = Graphics.FromImage(bmp))
            using (var pen = new System.Drawing.Pen(System.Drawing.Color.White))
            {
                // draw one thousand random white lines on a dark blue background
                gfx.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
                gfx.Clear(System.Drawing.Color.Navy);
                for (int i = 0; i < 1000; i++)
                {
                    var pt1 = new System.Drawing.Point(rand.Next(bmp.Width), rand.Next(bmp.Height));
                    var pt2 = new System.Drawing.Point(rand.Next(bmp.Width), rand.Next(bmp.Height));
                    gfx.DrawLine(pen, pt1, pt2);
                }
                this.Background=new ImageBrush(GenerateBMIFromBitmap(bmp));
            }
        }
    }
}