<Window x:Class="WpfAppViewboxImage.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:WpfAppViewboxImage"
          mc:Ignorable="d"
          Title="MainWindow" Height="450" Width="800">
     <Canvas>

          <Viewbox Canvas.Left="{Binding X}" Canvas.Top="{Binding Y}" Width="{Binding W}" Height="{Binding H}">
               <ContentPresenter Content="{Binding MyContent}"/>
          </Viewbox>

     </Canvas>
</Window>

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace WpfAppViewboxImage
{
     public partial class MainWindow : Window
     {
          public Image MyContent { get; set; }
          public int X { get; set; }
          public int Y { get; set; }
          public int W { get; set; }
          public int H { get; set; }

          public MainWindow()
          {
               InitializeComponent();

               // for binding
               this.DataContext = this;

               // set content using binding
               MyContent = new Image();
               MyContent.Source = new BitmapImage(new Uri("d://1.png", UriKind.Absolute));

               X = 500;
               Y = 5;
               W = 150;
               H = 110;
          }

     }
}