diff --git a/butterflow-ui/FlowFilterType.cs b/butterflow-ui/FlowFilterType.cs
new file mode 100644
index 0000000..2d125b0
--- /dev/null
+++ b/butterflow-ui/FlowFilterType.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace butterflow_ui
+{
+    /// <summary> Values that represent a flow filter type used for optical flow calculations. </summary>
+    [Serializable]
+    public enum FlowFilterType
+    {
+        /// <summary> Box. </summary>
+        box,
+        /// <summary> Guassian. </summary>
+        guassian
+    }
+}
diff --git a/butterflow-ui/Localization/Localization.Designer.cs b/butterflow-ui/Localization/Localization.Designer.cs
index db8c665..afd0955 100644
--- a/butterflow-ui/Localization/Localization.Designer.cs
+++ b/butterflow-ui/Localization/Localization.Designer.cs
@@ -249,6 +249,24 @@ namespace butterflow_ui.Localization {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Flow Filter.
+        /// </summary>
+        public static string FlowFilterLabel {
+            get {
+                return ResourceManager.GetString("FlowFilterLabel", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Filter used for optical flow estimation..
+        /// </summary>
+        public static string FlowFilterTooltip {
+            get {
+                return ResourceManager.GetString("FlowFilterTooltip", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Height.
         /// </summary>
@@ -303,6 +321,24 @@ namespace butterflow_ui.Localization {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Keep Subregions.
+        /// </summary>
+        public static string KeepSubregionsLabel {
+            get {
+                return ResourceManager.GetString("KeepSubregionsLabel", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Renders subregions not explicitly specified..
+        /// </summary>
+        public static string KeepSubregionsTooltip {
+            get {
+                return ResourceManager.GetString("KeepSubregionsTooltip", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Levels.
         /// </summary>
diff --git a/butterflow-ui/Localization/Localization.resx b/butterflow-ui/Localization/Localization.resx
index ebf53cf..8fe7f88 100644
--- a/butterflow-ui/Localization/Localization.resx
+++ b/butterflow-ui/Localization/Localization.resx
@@ -240,12 +240,24 @@
   <data name="FastPyramidsTooltip" xml:space="preserve">
     <value />
   </data>
+  <data name="FlowFilterLabel" xml:space="preserve">
+    <value>Flow Filter</value>
+  </data>
+  <data name="FlowFilterTooltip" xml:space="preserve">
+    <value>Filter used for optical flow estimation.</value>
+  </data>
   <data name="IterationsLabel" xml:space="preserve">
     <value>Pyramid iterations</value>
   </data>
   <data name="IterationsTooltip" xml:space="preserve">
     <value>The number of iterations to use for each pyramid layer.</value>
   </data>
+  <data name="KeepSubregionsLabel" xml:space="preserve">
+    <value>Keep Subregions</value>
+  </data>
+  <data name="KeepSubregionsTooltip" xml:space="preserve">
+    <value>Renders subregions not explicitly specified.</value>
+  </data>
   <data name="LevelsLabel" xml:space="preserve">
     <value>Levels</value>
   </data>
diff --git a/butterflow-ui/MainWindow.xaml b/butterflow-ui/MainWindow.xaml
index 0338a63..364caf6 100644
--- a/butterflow-ui/MainWindow.xaml
+++ b/butterflow-ui/MainWindow.xaml
@@ -11,12 +11,18 @@
         x:Name="butterflowUIWindow"
         Title="{x:Static loc:Localization.Title}" Height="600" Width="800">
     <Window.Resources>
-        <ObjectDataProvider x:Key="enumDataProvider" MethodName="GetValues"
+        <ObjectDataProvider x:Key="enumRegionTypeDataProvider" MethodName="GetValues"
                             ObjectType="{x:Type System:Enum}">
             <ObjectDataProvider.MethodParameters>
                 <x:Type TypeName="butterflow_ui:RegionType"/>
             </ObjectDataProvider.MethodParameters>
         </ObjectDataProvider>
+        <ObjectDataProvider x:Key="enumFlowFilterTypeDataProvider" MethodName="GetValues"
+                            ObjectType="{x:Type System:Enum}">
+            <ObjectDataProvider.MethodParameters>
+                <x:Type TypeName="butterflow_ui:FlowFilterType"/>
+            </ObjectDataProvider.MethodParameters>
+        </ObjectDataProvider>
     </Window.Resources>
     <DockPanel>
         <Menu DockPanel.Dock="Top">
@@ -109,7 +115,7 @@
                                     <RadioButton GroupName="PlaybackRate" Checked="PlaybackRateRadioButton_Checked" Content="{x:Static loc:Localization._120fpsLabel}" Tag="120" />
                                 </butterflow_ui:ButterflowOption>
                                 <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.CustomPlaybackRateLabel}" DescriptionValue="{x:Static loc:Localization.PlaybackRateDescription}">
-                                    <TextBox Text="{Binding OptionsConfiguration.PlaybackRate, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}"  />
+                                    <TextBox Text="{Binding OptionsConfiguration.PlaybackRate, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}" GotFocus="TextBox_GotFocus"  />
                                 </butterflow_ui:ButterflowOption>
                             </StackPanel>
                         </butterflow_ui:ButterflowOption>
@@ -157,7 +163,18 @@
 
                                 </Button>
                                 <butterflow_ui:ButterflowOption Grid.Column="2" LabelValue="{x:Static loc:Localization.HeightLabel}">
-                                    <TextBox Text="{Binding OptionsConfiguration.Height, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" IsReadOnly="{Binding OptionsConfiguration.LockAspectRatio, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}" />
+                                    <TextBox Text="{Binding OptionsConfiguration.Height, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" IsReadOnly="{Binding OptionsConfiguration.LockAspectRatio, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}">
+                                        <TextBox.Style>
+                                            <Style TargetType="{x:Type TextBox}">
+                                                <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlColor}}" />
+                                                <Style.Triggers>
+                                                    <Trigger Property="IsReadOnly" Value="True">
+                                                        <Setter Property="Background" Value="Gray" />
+                                                    </Trigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </TextBox.Style>
+                                    </TextBox>
                                 </butterflow_ui:ButterflowOption>
                             </Grid>
                         </butterflow_ui:ButterflowOption>
@@ -176,7 +193,7 @@
                                             <TextBlock Text="{Binding Start, Converter={x:Static gu:TimeSpanToStringConverter.Default}}" ToolTip="{Binding Start}"/>
                                             <TextBlock Text="{x:Static loc:Localization.EndLabel}" />
                                             <TextBlock Text="{Binding End, Converter={x:Static gu:TimeSpanToStringConverter.Default}}" ToolTip="{Binding End}"/>
-                                            <ComboBox ItemsSource="{Binding Source={StaticResource enumDataProvider}}" SelectedItem="{Binding SubregionType, Mode=TwoWay}"/>
+                                            <ComboBox ItemsSource="{Binding Source={StaticResource enumRegionTypeDataProvider}}" SelectedItem="{Binding SubregionType, Mode=TwoWay}"/>
                                             <TextBox MinWidth="35" Text="{Binding Value, Mode=TwoWay}" />
                                             <TextBlock Text="{x:Static loc:Localization.ToEndLabel}" />
                                             <CheckBox IsChecked="{Binding ToEnd, Mode=TwoWay}" />
@@ -185,6 +202,9 @@
                                 </ListView.ItemTemplate>
                             </ListView>
                         </butterflow_ui:ButterflowOption>
+                        <butterflow_ui:ButterflowOption DescriptionValue="{x:Static loc:Localization.KeepSubregionsTooltip}">
+                            <CheckBox IsChecked="{Binding OptionsConfiguration.KeepSubregions, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}" Content="{x:Static loc:Localization.KeepSubregionsLabel}" />
+                        </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption DescriptionValue="{x:Static loc:Localization.SmoothMotionTooltip}">
                             <CheckBox IsChecked="{Binding OptionsConfiguration.SmoothMotion, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}" Content="{x:Static loc:Localization.SmoothMotionLabel}" />
                         </butterflow_ui:ButterflowOption>
@@ -195,19 +215,22 @@
                             <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
                         </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.LevelsLabel}" DescriptionValue="{x:Static loc:Localization.LevelsTooltip}">
-                            <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                            <TextBox Text="{Binding OptionsConfiguration.Levels, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
                         </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.WindowSizeLabel}" DescriptionValue="{x:Static loc:Localization.WindowSizeTooltip}">
-                            <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                            <TextBox Text="{Binding OptionsConfiguration.WindowSize, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
                         </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.IterationsLabel}" DescriptionValue="{x:Static loc:Localization.IterationsTooltip}">
-                            <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                            <TextBox Text="{Binding OptionsConfiguration.Iterations, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
                         </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.PixelNeighborhoodLabel}" DescriptionValue="{x:Static loc:Localization.PixelNeighborhoodTooltip}">
-                            <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                            <TextBox Text="{Binding OptionsConfiguration.PixelNeighborhood, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
                         </butterflow_ui:ButterflowOption>
                         <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.SmoothDerivativeLabel}" DescriptionValue="{x:Static loc:Localization.SmoothDerivativeTooltip}">
-                            <TextBox Text="{Binding OptionsConfiguration.PyramidScale, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                            <TextBox Text="{Binding OptionsConfiguration.SmoothDerivativeStandardDeviation, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=LostFocus}" />
+                        </butterflow_ui:ButterflowOption>
+                        <butterflow_ui:ButterflowOption LabelValue="{x:Static loc:Localization.FlowFilterLabel}" DescriptionValue="{x:Static loc:Localization.FlowFilterTooltip}">
+                            <ComboBox ItemsSource="{Binding Source={StaticResource enumFlowFilterTypeDataProvider}}" SelectedItem="{Binding OptionsConfiguration.FlowFilterType, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type butterflow_ui:MainWindow}}, UpdateSourceTrigger=PropertyChanged}"/>
                         </butterflow_ui:ButterflowOption>
                     </StackPanel>
                 </ScrollViewer>
diff --git a/butterflow-ui/MainWindow.xaml.cs b/butterflow-ui/MainWindow.xaml.cs
index c53b523..158d752 100644
--- a/butterflow-ui/MainWindow.xaml.cs
+++ b/butterflow-ui/MainWindow.xaml.cs
@@ -47,6 +47,39 @@ namespace butterflow_ui
             InitializeComponent();
         }
 
+        #region Methods
+
+        /// <summary> Gets the recursive children of a <paramref name="parent"/> element that are of type <typeparamref name="T"/>. </summary>
+        /// <typeparam name="T"> Generic type parameter. </typeparam>
+        /// <param name="parent"> The parent element. </param>
+        /// <returns>
+        /// An enumerator that allows foreach to be used to process the recursive childrens in this
+        /// collection.
+        /// </returns>
+        private IEnumerable<T> GetRecursiveChildren<T>(object parent) where T : DependencyObject
+        {
+            if (parent is DependencyObject)
+            {
+                var list = new List<T>();
+
+                foreach (var child in LogicalTreeHelper.GetChildren((DependencyObject)parent))
+                {
+                    if (child is DependencyObject)
+                    {
+                        if (child is T)
+                        {
+                            list.Add((T)child);
+                        }
+                        list.AddRange(GetRecursiveChildren<T>((DependencyObject)child));
+                    }
+                }
+
+                return list;
+            }
+
+            return Enumerable.Empty<T>();
+        }
+
         /// <summary> Butterflow wrapper parsed console output recieved. </summary>
         /// <param name="sender"> Source of the event. </param>
         /// <param name="e">      The ButterflowOutputArgs to process. </param>
@@ -234,5 +267,21 @@ namespace butterflow_ui
                 }
             }
         }
+
+        /// <summary> Event handler. Called by TextBox for got focus events. </summary>
+        /// <param name="sender"> Source of the event. </param>
+        /// <param name="e">      Routed event information. </param>
+        private void TextBox_GotFocus(object sender, RoutedEventArgs e)
+        {
+            //Clear all the radio buttons because we got focus from the user in the playbackrate textbox.
+            var playbackRateRadioButtons = GetRecursiveChildren<RadioButton>(this.butterflowUIWindow);
+
+            foreach(var radioButton in playbackRateRadioButtons)
+            {
+                radioButton.IsChecked = false;
+            }
+        }
+
+        #endregion
     }
 }
diff --git a/butterflow-ui/OptionsConfiguration.cs b/butterflow-ui/OptionsConfiguration.cs
index 4932c43..e52fb37 100644
--- a/butterflow-ui/OptionsConfiguration.cs
+++ b/butterflow-ui/OptionsConfiguration.cs
@@ -16,6 +16,14 @@ namespace butterflow_ui
     {
         #region Members
 
+        private const decimal DEFAULT_PYRAMID_SCALE = 0.5m;
+        private const int DEFAULT_LEVELS = 3;
+        private const int DEFAULT_WINDOW_SIZE = 25;
+        private const int DEFAULT_ITERATIONS = 3;
+        private const int DEFAULT_PIXEL_NEIGHBORHOOD = 5;
+        private const decimal DEFAULT_SMOOTH_DERIVATIVE_STANDARD_DEVIATION = 1.1m;
+        private const FlowFilterType DEFAULT_FLOW_FILTER_TYPE = FlowFilterType.box;
+
         /// <summary> An interpreter used to ensure numeric input is correctly calculated. </summary>
         private InputInterpreter interpreter = new InputInterpreter();
         /// <summary> The aspect ratio used for calculating heights when the aspect ratio is locked. </summary>
@@ -25,7 +33,7 @@ namespace butterflow_ui
         private bool keepAudio;
         private int width;
         private int height;
-        private bool keepAspectRatio;
+        private bool keepSubRegions;
         private bool losslessQuality;
         private bool smoothMotion;
         private bool lockAspectRatio;
@@ -38,6 +46,7 @@ namespace butterflow_ui
         private int iterations;
         private int pixelNeighborhood;
         private decimal smoothDerivativeStandardDeviation;
+        private FlowFilterType flowFilterType = FlowFilterType.box;
         private ObservableCollection<ButterflowSubregion> subregions = new ObservableCollection<ButterflowSubregion>();
 
         #endregion
@@ -109,7 +118,7 @@ namespace butterflow_ui
             }
             set
             {
-                if (value)
+                if (value && this.width != 0 && this.height != 0)
                 {
                     this.aspectRatio = Convert.ToDecimal(this.height) / Convert.ToDecimal(this.width);
                 }
@@ -162,17 +171,17 @@ namespace butterflow_ui
             }
         }
 
-        /// <summary> Gets or sets a value indicating whether the keep aspect ratio of the input video file for the output video file. </summary>
-        /// <value> True if keep aspect ratio, false if not. </value>
-        public bool KeepAspectRatio
+        /// <summary> Gets or sets a value indicating whether the keep subregions that are not explicitly specified. </summary>
+        /// <value> True if keeping subregions not explicitly specified, false if not. </value>
+        public bool KeepSubregions
         {
             get
             {
-                return this.keepAspectRatio;
+                return this.keepSubRegions;
             }
             set
             {
-                this.keepAspectRatio = value;
+                this.keepSubRegions = value;
                 OnPropertyChanged();
             }
         }
@@ -312,7 +321,13 @@ namespace butterflow_ui
             set
             {
                 interpreter.Interpret(value);
-                this.pixelNeighborhood = interpreter.Int;
+
+                // Per butterflow's documentation, the valid range for --poly-n is {5,7}
+                if (interpreter.Int >= 5 || interpreter.Int <= 7)
+                {
+                    this.pixelNeighborhood = interpreter.Int;
+                }
+
                 OnPropertyChanged();
             }
         }
@@ -333,6 +348,21 @@ namespace butterflow_ui
             }
         }
 
+        /// <summary> Gets or sets the type of the flow filter used for optical flow calculations. </summary>
+        /// <value> The type of the flow filter used for optical flow calculations. </value>
+        public FlowFilterType FlowFilterType
+        {
+            get
+            {
+                return this.flowFilterType;
+            }
+            set
+            {
+                this.flowFilterType = value;
+                OnPropertyChanged();
+            }
+        }
+
         /// <summary> Gets or sets the subregions of the video on which to work. </summary>
         /// <value> The subregions of the video. </value>
         public ObservableCollection<ButterflowSubregion> Subregions
@@ -355,12 +385,24 @@ namespace butterflow_ui
         /// <summary> Default constructor. </summary>
         public OptionsConfiguration()
         {
+            // Set default values
+            this.pyramidScale = DEFAULT_PYRAMID_SCALE;
+            this.levels = DEFAULT_LEVELS;
+            this.windowSize = DEFAULT_WINDOW_SIZE;
+            this.iterations = DEFAULT_ITERATIONS;
+            this.pixelNeighborhood = DEFAULT_PIXEL_NEIGHBORHOOD;
+            this.smoothDerivativeStandardDeviation = DEFAULT_SMOOTH_DERIVATIVE_STANDARD_DEVIATION;
+            this.flowFilterType = DEFAULT_FLOW_FILTER_TYPE;
+
             AddConstantCallProperty("CommandLineOutput");
 
-            this.subregions.CollectionChanged += SubregionsCollectionChanged;
+            this.subregions.CollectionChanged += Subregions_CollectionChanged; ;
         }
 
-        private void SubregionsCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
+        /// <summary> Event handler. Called by Subregions for collection changed events. </summary>
+        /// <param name="sender"> Source of the event. </param>
+        /// <param name="e">      Notify collection changed event information. </param>
+        private void Subregions_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
         {
             if (e.NewItems != null)
             {
@@ -393,9 +435,9 @@ namespace butterflow_ui
         /// <returns> This object as a string. </returns>
         public string ToButterflowArguments()
         {
-            var stringBuilder = new StringBuilder("-v "); //Verbose
+            var stringBuilder = new StringBuilder("-v "); // Verbose
 
-            if (this.KeepAspectRatio)
+            if (this.LockAspectRatio)
             {
                 stringBuilder.AppendFormat("-vs {0}:-1 ", this.Width);
             }
@@ -435,6 +477,17 @@ namespace butterflow_ui
                 stringBuilder.Append(" ");
             }
 
+            if (this.KeepSubregions) stringBuilder.Append("-k ");
+            if (this.SmoothMotion) stringBuilder.Append("-sm ");
+            if (this.FastPyramid) stringBuilder.Append("--fast-pyr ");
+            if (this.pyramidScale != DEFAULT_PYRAMID_SCALE) stringBuilder.AppendFormat("--pyr-scale {0} ", this.PyramidScale);
+            if (this.levels != DEFAULT_LEVELS) stringBuilder.AppendFormat("--levels {0} ", this.Levels);
+            if (this.windowSize != DEFAULT_WINDOW_SIZE) stringBuilder.AppendFormat("--winsize {0} ", this.WindowSize);
+            if (this.iterations != DEFAULT_ITERATIONS) stringBuilder.AppendFormat("--iters {0} ", this.Iterations);
+            if (this.pixelNeighborhood != DEFAULT_PIXEL_NEIGHBORHOOD) stringBuilder.AppendFormat("--poly-n {0} ", this.PixelNeighborhood);
+            if (this.smoothDerivativeStandardDeviation != DEFAULT_SMOOTH_DERIVATIVE_STANDARD_DEVIATION) stringBuilder.AppendFormat("--poly-s {0} ", this.SmoothDerivativeStandardDeviation);
+            if (this.FlowFilterType != DEFAULT_FLOW_FILTER_TYPE) stringBuilder.AppendFormat("-ff {0} ", this.FlowFilterType);
+
             return stringBuilder.ToString();
         }
 
diff --git a/butterflow-ui/RegionType.cs b/butterflow-ui/RegionType.cs
index 97363e0..6515cfe 100644
--- a/butterflow-ui/RegionType.cs
+++ b/butterflow-ui/RegionType.cs
@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 namespace butterflow_ui
 {
     /// <summary> Values that represent subregion types. </summary>
+    [Serializable]
     public enum RegionType
     {
         /// <summary> Speed. </summary>
diff --git a/butterflow-ui/butterflow-ui.csproj b/butterflow-ui/butterflow-ui.csproj
index b88aa9b..cc232c0 100644
--- a/butterflow-ui/butterflow-ui.csproj
+++ b/butterflow-ui/butterflow-ui.csproj
@@ -60,6 +60,7 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </ApplicationDefinition>
+    <Compile Include="FlowFilterType.cs" />
     <Compile Include="PropertyChangedAlerter.cs" />
     <Compile Include="RegionType.cs" />
     <Page Include="Icons.xaml">