WPF Image ZoomIn ZoomOut Pan/Move Rotate

<Window x:Class="WpfApp162.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp162"
        mc:Ignorable="d" WindowState="Maximized"
        Title="MainWindow" Height="450" Width="800">
    <Grid >
        <Grid.RowDefinitions>
            <RowDefinition Height="30"/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <ToolBar Grid.Row="0">
            <Button Content="Open"  x:Name="openBtn" Click="openBtn_Click"/>
            <Button Content="Rotate 45d" x:Name="rotateBtn" Click="rotateBtn_Click"/>
        </ToolBar>
        <Grid x:Name="gd" Grid.Row="1" Background="Transparent" MouseDown="Grid_MouseDown" MouseMove="Grid_MouseMove" 
          MouseUp="Grid_MouseUp" MouseWheel="Grid_MouseWheel" ClipToBounds="True">
            <Image x:Name="img" ClipToBounds="True">
                <Image.RenderTransform>
                    <TransformGroup>
                        <ScaleTransform x:Name="scaler"/>
                        <TranslateTransform x:Name="translater"/>
                        <RotateTransform x:Name="rotater"/>
                    </TransformGroup>
                </Image.RenderTransform>
            </Image>
        </Grid>
    </Grid>
</Window>


using Microsoft.Win32;
using System;
using System.Collections.Generic;
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;

namespace WpfApp162
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        Point oldPoint { get; set; }
        public bool isMoving { get; set; } = false;
        private void Grid_MouseDown(object sender, MouseButtonEventArgs e)
        {
            oldPoint = e.GetPosition(gd);
        }

        private void Grid_MouseMove(object sender, MouseEventArgs e)
        {
            isMoving = true;
        }

        private void Grid_MouseUp(object sender, MouseButtonEventArgs e)
        {
            if(isMoving && e.ChangedButton==MouseButton.Left && e.ButtonState == MouseButtonState.Released)
            {
                Point newPoint = e.GetPosition(gd);
                translater.X += newPoint.X - oldPoint.X;
                translater.Y += newPoint.Y - oldPoint.Y;
                isMoving = false;
            }
        }

        private void Grid_MouseWheel(object sender, MouseWheelEventArgs e)
        {
            if(e.Delta>0)
            {
                scaler.ScaleX *= 1.2;
                scaler.ScaleY *= 1.2;
            }
            else
            {
                scaler.ScaleX /= 1.2;
                scaler.ScaleY /= 1.2;
            }
            scaler.CenterX = e.GetPosition(gd).X;
            scaler.CenterY = e.GetPosition(gd).Y;
        }

        private void openBtn_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();

            if (ofd.ShowDialog()==true)
            {
                scaler.ScaleX = 1.0;
                scaler.ScaleY=1.0;
                scaler.CenterX = 0;
                scaler.CenterY = 0;
                rotater.Angle = 0;
                string imgUrl=ofd.FileName;
                BitmapImage bmi = new BitmapImage();
                bmi.BeginInit();
                bmi.UriSource=new Uri(imgUrl, UriKind.RelativeOrAbsolute);
                bmi.EndInit();
                img.Source= bmi;
            }
        }

        private void rotateBtn_Click(object sender, RoutedEventArgs e)
        {
            rotater.Angle += 45;
            rotater.CenterX = this.ActualWidth / 2;
            rotater.CenterY = this.ActualHeight / 2;
        }
    }
}