MainWindow.xaml

<Window x:Class="perspectivePlayground.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="583" Width="832" Loaded="MainWindow_OnLoaded">
    <Grid>
        <Canvas >
            <Image Name="Image" />
            <Thumb Canvas.Top="0" Canvas.Left="0" Width="15" Height="15" DragDelta="ThumbTopLeft_OnDragDelta" Name="ThumbTopLeft" Background="Red"></Thumb>
            <Thumb Canvas.Top="0" Canvas.Left="100" Width="15" Height="15" DragDelta="ThumbTopLeft_OnDragDelta" Name="ThumbTopRight" Background="Green"></Thumb>
            <Thumb Canvas.Top="100" Canvas.Left="0" Width="15" Height="15" DragDelta="ThumbTopLeft_OnDragDelta" Name="ThumbBottomLeft" Background="White"></Thumb>
            <Thumb Canvas.Top="100" Canvas.Left="100" Width="15" Height="15" DragDelta="ThumbTopLeft_OnDragDelta" Name="ThumbBottomRight" Background="Blue"></Thumb>
        </Canvas>
    </Grid>
</Window>