How to select the individual image and then click the button

Hi,
How to select the individual image and then click the button,need to send the selected image value?

   Each rectangle inside i added image control.when click the submit button,send the image value ,which image i select.How to select the image.Here image selection is not working.please help me.(wpf using mvvm)


SampleView.xaml:

             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d"
           d:DesignHeight="600" d:DesignWidth="1241" >

   
       

                      
              
                       
          


           
          
           


        
           

       
   


SampleView.xaml.cs:
 public partial class SampleView: UserControl
    {
        public SampleView()
        {
            InitializeComponent();
            this.DataContext = new SampleViewModel();
        }
    }

SampleViewModel.cs:
 public class SampleViewModel: INotifyPropertyChanged
    {
        public SampleViewModel()
        {
           
            this.SubmitCommand = new DelegateCommand