ZoomableImage.xaml

<UserControl x:Class="ImageToMidi.ZoomableImage"
             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" 
             xmlns:local="clr-namespace:ImageToMidi"
             xmlns:skia="clr-namespace:SkiaSharp.Views.WPF;assembly=SkiaSharp.Views.WPF"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid x:Name="container" Background="Transparent"
          MouseWheel="Container_MouseWheel"
          SizeChanged="Container_SizeChanged"
          MouseDown="Container_MouseDown"
          MouseMove="Container_MouseMove"
          MouseUp="Container_MouseUp">
        <skia:SKElement x:Name="skiaElement" PaintSurface="OnPaintSurface" />
    </Grid>
</UserControl>