v2.21.1v2.21.1

- **(Add) Layer outline:**
   - Blob outline: Outline all separate blobs
   - Centroids: Draw a dot at the gemoetric center of a blob
- (Add) Adjust layer height: Allow to change exposure time on the dialog and inform that different layer thickness require different exposure times
- (Add) Resin trap detection: Allow to choose the starting layer index for resin trap detection which will also be considered a drain layer.
        Use this setting to bypass complicated rafts by selected the model first real layer (#221)
- (Improvement) Disable mirroed preview when loading a file that is not mirroed

16 files changed, 381 insertions, 43 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c921ace..40444c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## 06/09/2021 - v2.21.1
+
+- **(Add) Layer outline:**
+   - Blob outline: Outline all separate blobs
+   - Centroids: Draw a dot at the gemoetric center of a blob
+- (Add) Adjust layer height: Allow to change exposure time on the dialog and inform that different layer thickness require different exposure times
+- (Add) Resin trap detection: Allow to choose the starting layer index for resin trap detection which will also be considered a drain layer.  
+        Use this setting to bypass complicated rafts by selected the model first real layer (#221)
+- (Improvement) Disable mirroed preview when loading a file that is not mirroed
+
 ## 03/09/2021 - v2.21.0
 
 - **UI:**
diff --git a/UVtools.Core/EmguCV/Contour.cs b/UVtools.Core/EmguCV/Contour.cs
index 20d216e..291cad8 100644
--- a/UVtools.Core/EmguCV/Contour.cs
+++ b/UVtools.Core/EmguCV/Contour.cs
@@ -90,7 +90,7 @@ namespace UVtools.Core.EmguCV
         /// <summary>
         /// Gets the centroid of the contour
         /// </summary>
-        public Point Centroid => _centroid ??= Moments.M00 == 0 ? Point.Empty : 
+        public Point Centroid => _centroid ??= Moments.M00 == 0 ? new Point(-1,-1) : 
             new Point(
             (int)Math.Round(_moments.M10 / _moments.M00),
             (int)Math.Round(_moments.M01 / _moments.M00));
@@ -211,6 +211,18 @@ namespace UVtools.Core.EmguCV
         }*/
         #endregion
 
+        #region Static methods
+        public static Point GetCentroid(VectorOfPoint points)
+        {
+            if (points is null || points.Length == 0) return new Point(-1, -1);
+            using var moments = CvInvoke.Moments(points);
+            return moments.M00 == 0 ? new Point(-1, -1) :
+                new Point(
+                    (int)Math.Round(moments.M10 / moments.M00),
+                    (int)Math.Round(moments.M01 / moments.M00));
+        }
+        #endregion
+
         #region Implementations
 
         public IEnumerator<Point> GetEnumerator()
diff --git a/UVtools.Core/Layer/LayerIssue.cs b/UVtools.Core/Layer/LayerIssue.cs
index 8b46e51..598231f 100644
--- a/UVtools.Core/Layer/LayerIssue.cs
+++ b/UVtools.Core/Layer/LayerIssue.cs
@@ -159,6 +159,12 @@ namespace UVtools.Core
         public bool Enabled { get; set; } = true;
 
         /// <summary>
+        /// Gets or sets the starting layer index for the detection which will also be considered a drain layer.
+        /// Use this setting to bypass complicated rafts by selected the model first real layer.
+        /// </summary>
+        public uint StartLayerIndex { get; set; }
+
+        /// <summary>
         /// Gets or sets the binary threshold, all pixels below this value will turn in black, otherwise white
         /// Set to 0 to disable this operation
         /// </summary>
diff --git a/UVtools.Core/Layer/LayerManager.cs b/UVtools.Core/Layer/LayerManager.cs
index 678c298..ba1ed48 100644
--- a/UVtools.Core/Layer/LayerManager.cs
+++ b/UVtools.Core/Layer/LayerManager.cs
@@ -1389,7 +1389,7 @@ namespace UVtools.Core
 
                                 listHollowArea.Add(new LayerHollowArea(contours[i].ToArray(),
                                     rect,
-                                    layer.Index == 0 ||
+                                    layer.Index <= resinTrapConfig.StartLayerIndex ||
                                     layer.Index == LayerCount - 1 // First and Last layers, always drains
                                         ? LayerHollowArea.AreaType.Drain
                                         : LayerHollowArea.AreaType.Unknown));
@@ -1410,7 +1410,7 @@ namespace UVtools.Core
 
                 ResinTrapTree resinTrapTree = new();
 
-                for (uint layerIndex = 1; layerIndex < LayerCount - 1; layerIndex++) // First and Last layers, always drains
+                for (uint layerIndex = resinTrapConfig.StartLayerIndex+1; layerIndex < LayerCount - 1; layerIndex++) // First and Last layers, always drains
                 {
                     if (progress.Token.IsCancellationRequested) break;
                     if (!layerHollowAreas.TryGetValue(layerIndex, out var areas))
diff --git a/UVtools.Core/Operations/OperationDoubleExposure.cs b/UVtools.Core/Operations/OperationDoubleExposure.cs
index 5de3e0e..96068d9 100644
--- a/UVtools.Core/Operations/OperationDoubleExposure.cs
+++ b/UVtools.Core/Operations/OperationDoubleExposure.cs
@@ -45,7 +45,7 @@ namespace UVtools.Core.Operations
             "The double exposure method clones the selected layer range and print the same layer twice with different exposure times and strategies.\n" +
             "Can be used to eliminate the elephant foot effect or to harden a layer in two steps.\n" +
             "After this, do not apply any modification which reconstruct the z positions of the layers.\n" +
-            "Note: To eliminate the elephant foot effect, the use of wall dimming method recommended.";
+            "Note: To eliminate the elephant foot effect, the use of wall dimming method is recommended.";
 
         public override string ConfirmationText =>
             $"double exposure model layers {LayerIndexStart} through {LayerIndexEnd}";
diff --git a/UVtools.Core/Operations/OperationLayerReHeight.cs b/UVtools.Core/Operations/OperationLayerReHeight.cs
index 44f153d..f9a86a6 100644
--- a/UVtools.Core/Operations/OperationLayerReHeight.cs
+++ b/UVtools.Core/Operations/OperationLayerReHeight.cs
@@ -38,6 +38,8 @@ namespace UVtools.Core.Operations
         #region Members
         private OperationLayerReHeightItem _selectedItem;
         private OperationLayerReHeightAntiAliasingType _antiAliasingType;
+        private decimal _bottomExposure;
+        private decimal _normalExposure;
 
         #endregion
 
@@ -49,7 +51,8 @@ namespace UVtools.Core.Operations
         public override string Description =>
             "Adjust the layer height of the model.\n\n" +
             "Adjusting to values lower than current height will reduce layer lines, adjusting to values higher" +
-            " than current height will reduce model detail.\n\n" +
+            " than current height will reduce model detail.\n" +
+            "Different layer thickness will require different exposure times, adjust accordingly.\n\n" +
             "Note: Using dedicated slicer software to re-slice will usually yeild better results.";
         public override string ConfirmationText =>
             $"adjust layer height to {SelectedItem.LayerHeight}mm?";
@@ -87,7 +90,9 @@ namespace UVtools.Core.Operations
 
         public override string ToString()
         {
-            var result = $"[Layer Count: {SelectedItem.LayerCount}] [Layer Height: {SelectedItem.LayerHeight}]" + LayerRangeString;
+            var result = $"[Layer Count: {SelectedItem.LayerCount}] " +
+                         $"[Layer Height: {SelectedItem.LayerHeight}] " +
+                         $"[Exposure: {_bottomExposure}/{_normalExposure}s]" + LayerRangeString;
             if (!string.IsNullOrEmpty(ProfileName)) result = $"{ProfileName}: {result}";
             return result;
         }
@@ -115,6 +120,18 @@ namespace UVtools.Core.Operations
             set => RaiseAndSetIfChanged(ref _antiAliasingType, value);
         }
 
+        public decimal BottomExposure
+        {
+            get => _bottomExposure;
+            set => RaiseAndSetIfChanged(ref _bottomExposure, Math.Round(value, 2));
+        }
+
+        public decimal NormalExposure
+        {
+            get => _normalExposure;
+            set => RaiseAndSetIfChanged(ref _normalExposure, Math.Round(value, 2));
+        }
+
 
         public static OperationLayerReHeightItem[] GetItems(uint layerCount, decimal layerHeight)
         {
@@ -158,6 +175,9 @@ namespace UVtools.Core.Operations
             {
                 _selectedItem = Presets[0];
             }
+
+            if (_bottomExposure <= 0) _bottomExposure = (decimal)SlicerFile.BottomExposureTime;
+            if (_normalExposure <= 0) _normalExposure = (decimal)SlicerFile.ExposureTime;
         }
 
         #endregion
@@ -297,8 +317,14 @@ namespace UVtools.Core.Operations
 
             progress.Token.ThrowIfCancellationRequested();
 
-            SlicerFile.LayerHeight = (float)SelectedItem.LayerHeight;
-            SlicerFile.LayerManager.Layers = layers;
+            SlicerFile.SuppressRebuildPropertiesWork(() =>
+            {
+                SlicerFile.LayerHeight = (float)SelectedItem.LayerHeight;
+                SlicerFile.BottomExposureTime = (float)_bottomExposure;
+                SlicerFile.ExposureTime = (float)_normalExposure;
+                SlicerFile.LayerManager.Layers = layers;
+            }, true);
+            
 
             return !progress.Token.IsCancellationRequested;
         }
diff --git a/UVtools.Core/UVtools.Core.csproj b/UVtools.Core/UVtools.Core.csproj
index fc4b636..268f850 100644
--- a/UVtools.Core/UVtools.Core.csproj
+++ b/UVtools.Core/UVtools.Core.csproj
@@ -10,7 +10,7 @@
     <RepositoryUrl>https://github.com/sn4k3/UVtools</RepositoryUrl>
     <PackageProjectUrl>https://github.com/sn4k3/UVtools</PackageProjectUrl>
     <Description>MSLA/DLP, file analysis, calibration, repair, conversion and manipulation</Description>
-    <Version>2.21.0</Version>
+    <Version>2.21.1</Version>
     <Copyright>Copyright © 2020 PTRTECH</Copyright>
     <PackageIcon>UVtools.png</PackageIcon>
     <Platforms>AnyCPU;x64</Platforms>
diff --git a/UVtools.WPF/Controls/Tools/ToolDoubleExposureControl.axaml b/UVtools.WPF/Controls/Tools/ToolDoubleExposureControl.axaml
index 56dd8ef..063ff3c 100644
--- a/UVtools.WPF/Controls/Tools/ToolDoubleExposureControl.axaml
+++ b/UVtools.WPF/Controls/Tools/ToolDoubleExposureControl.axaml
@@ -153,7 +153,7 @@
                    IsEnabled="{Binding Operation.SecondLayerDifference}"
                    ToolTip.Tip="When the 'Exposure the difference between first and second layer for the second layer' is active, 
 this setting will further erode the layer producing a overlap of n pixel perimeters over the previous layer"
-                   Text="Difference overlap margin:"/>
+                   Text="Difference overlap by:"/>
         <NumericUpDown
             Grid.Row="0" Grid.Column="2"
             VerticalAlignment="Center"
diff --git a/UVtools.WPF/Controls/Tools/ToolLayerReHeightControl.axaml b/UVtools.WPF/Controls/Tools/ToolLayerReHeightControl.axaml
index 168ac75..6a886f6 100644
--- a/UVtools.WPF/Controls/Tools/ToolLayerReHeightControl.axaml
+++ b/UVtools.WPF/Controls/Tools/ToolLayerReHeightControl.axaml
@@ -9,22 +9,41 @@
     <StackPanel Orientation="Vertical" Spacing="10">
     <TextBlock VerticalAlignment="Center" Text="{Binding CurrentLayers}"/>
 
-    <Grid RowDefinitions="Auto,10,Auto"
-          ColumnDefinitions="Auto,10,Auto">
+    <Grid RowDefinitions="Auto,10,Auto,10,Auto"
+          ColumnDefinitions="Auto,10,Auto,5,Auto,20,Auto,10,Auto,5,Auto">
 
         <TextBlock Grid.Row="0" Grid.Column="0"  VerticalAlignment="Center" Text="Modifier:"/>
         <ComboBox
-            Grid.Row="0" Grid.Column="2" Width="500"
+            Grid.Row="0" Grid.Column="2" Grid.ColumnSpan="9"
+            Width="430"
             SelectedItem="{Binding Operation.SelectedItem}"
-            Items="{Binding Operation.Presets}"
-        />
+            Items="{Binding Operation.Presets}"/>
 
         <TextBlock Grid.Row="2" Grid.Column="0"  VerticalAlignment="Center" Text="Anti-Aliasing:"/>
-        <ComboBox Grid.Row="2" Grid.Column="2"  Width="500"
+        <ComboBox Grid.Row="2" Grid.Column="2" Grid.ColumnSpan="9"
+                  Width="430"
                   IsEnabled="{Binding Operation.CanAntiAliasing}"
                   Items="{Binding Operation.AntiAliasingType, Converter={StaticResource EnumToCollectionConverter}, Mode=OneTime}"
                   SelectedItem="{Binding Operation.AntiAliasingType, Converter={StaticResource FromValueDescriptionToEnumConverter}}">
         </ComboBox>
+
+        <TextBlock Grid.Row="4" Grid.Column="0"  VerticalAlignment="Center" Text="Bottom exposure:"/>
+        <NumericUpDown Grid.Row="4" Grid.Column="2"
+                       VerticalAlignment="Center"
+                       Minimum="0.01"
+                       Maximum="1000"
+                       Increment="0.5"
+                       Value="{Binding Operation.BottomExposure}"/>
+        <TextBlock Grid.Row="4" Grid.Column="4"  VerticalAlignment="Center" Text="s"/>
+
+        <TextBlock Grid.Row="4" Grid.Column="6"  VerticalAlignment="Center" Text="Normal exposure:"/>
+        <NumericUpDown Grid.Row="4" Grid.Column="8"
+                       VerticalAlignment="Center"
+                       Minimum="0.01"
+                       Maximum="1000"
+                       Increment="0.5"
+                       Value="{Binding Operation.NormalExposure}"/>
+        <TextBlock Grid.Row="4" Grid.Column="10"  VerticalAlignment="Center" Text="s"/>
     </Grid>
 
     </StackPanel>
diff --git a/UVtools.WPF/MainWindow.Issues.cs b/UVtools.WPF/MainWindow.Issues.cs
index 1308b0e..8acfc62 100644
--- a/UVtools.WPF/MainWindow.Issues.cs
+++ b/UVtools.WPF/MainWindow.Issues.cs
@@ -44,9 +44,17 @@ namespace UVtools.WPF
         }
 
         public readonly List<LayerIssue> IgnoredIssues = new();
+        private uint _resinTrapDetectionStartLayer;
 
         public bool IssueCanGoPrevious => Issues.Count > 0 && _issueSelectedIndex > 0;
         public bool IssueCanGoNext => Issues.Count > 0 && _issueSelectedIndex < Issues.Count - 1;
+
+        public uint ResinTrapDetectionStartLayer
+        {
+            get => _resinTrapDetectionStartLayer;
+            set => RaiseAndSetIfChanged(ref _resinTrapDetectionStartLayer, value);
+        }
+
         #endregion
 
         #region Methods
@@ -526,7 +534,21 @@ namespace UVtools.WPF
             if(clearIgnored) IgnoredIssues.Clear();
         }
 
-        
+        public void SetResinTrapDetectionStartLayer(char which)
+        {
+            switch (which)
+            {
+                case 'N':
+                    ResinTrapDetectionStartLayer = SlicerFile.FirstNormalLayer.Index;
+                    break;
+                case 'C':
+                    ResinTrapDetectionStartLayer = ActualLayer;
+                    break;
+            }
+        }
+
+
+
         public IslandDetectionConfiguration GetIslandDetectionConfiguration(bool enable)
         {
             return new()
@@ -561,6 +583,7 @@ namespace UVtools.WPF
             return new()
             {
                 Enabled = enable,
+                StartLayerIndex = _resinTrapDetectionStartLayer,
                 BinaryThreshold = Settings.Issues.ResinTrapBinaryThreshold,
                 RequiredAreaToProcessCheck = Settings.Issues.ResinTrapRequiredAreaToProcessCheck,
                 RequiredBlackPixelsToDrain = Settings.Issues.ResinTrapRequiredBlackPixelsToDrain,
diff --git a/UVtools.WPF/MainWindow.LayerPreview.cs b/UVtools.WPF/MainWindow.LayerPreview.cs
index fd53e1d..06097c1 100644
--- a/UVtools.WPF/MainWindow.LayerPreview.cs
+++ b/UVtools.WPF/MainWindow.LayerPreview.cs
@@ -26,6 +26,7 @@ using Emgu.CV.Structure;
 using Emgu.CV.Util;
 using UVtools.AvaloniaControls;
 using UVtools.Core;
+using UVtools.Core.EmguCV;
 using UVtools.Core.Extensions;
 using UVtools.Core.PixelEditor;
 using UVtools.WPF.Controls;
@@ -74,7 +75,9 @@ namespace UVtools.WPF
         private bool _isPixelEditorActive;
         private bool _showLayerOutlinePrintVolumeBoundary;
         private bool _showLayerOutlineLayerBoundary;
+        private bool _showLayerOutlineContourBoundary;
         private bool _showLayerOutlineHollowAreas;
+        private bool _showLayerOutlineCentroids;
         private bool _showLayerOutlineEdgeDetection;
         private bool _showLayerOutlineDistanceDetection;
         private bool _showLayerOutlineSkeletonize;
@@ -107,7 +110,9 @@ namespace UVtools.WPF
             _showLayerImageDifference = Settings.LayerPreview.ShowLayerDifference;
             _showLayerOutlinePrintVolumeBoundary = Settings.LayerPreview.VolumeBoundsOutline;
             _showLayerOutlineLayerBoundary = Settings.LayerPreview.LayerBoundsOutline;
+            _showLayerOutlineContourBoundary = Settings.LayerPreview.ContourBoundsOutline;
             _showLayerOutlineHollowAreas = Settings.LayerPreview.HollowOutline;
+            _showLayerOutlineCentroids = Settings.LayerPreview.CentroidOutline;
             
             LayerImageBox.ZoomLevels = new AdvancedImageBox.ZoomLevelCollection(AppSettings.ZoomLevels);
             
@@ -370,6 +375,16 @@ namespace UVtools.WPF
             }
         }
 
+        public bool ShowLayerOutlineContourBoundary
+        {
+            get => _showLayerOutlineContourBoundary;
+            set
+            {
+                if (!RaiseAndSetIfChanged(ref _showLayerOutlineContourBoundary, value)) return;
+                ShowLayer();
+            }
+        }
+
         public bool ShowLayerOutlineHollowAreas
         {
             get => _showLayerOutlineHollowAreas;
@@ -380,6 +395,16 @@ namespace UVtools.WPF
             }
         }
 
+        public bool ShowLayerOutlineCentroids
+        {
+            get => _showLayerOutlineCentroids;
+            set
+            {
+                if (!RaiseAndSetIfChanged(ref _showLayerOutlineCentroids, value)) return;
+                ShowLayer();
+            }
+        }
+
         public bool ShowLayerOutlineEdgeDetection
         {
             get => _showLayerOutlineEdgeDetection;
@@ -983,6 +1008,21 @@ namespace UVtools.WPF
                         Settings.LayerPreview.LayerBoundsOutlineThickness);
                 }
 
+                if (_showLayerOutlineContourBoundary)
+                {
+                    for (int i = 0; i < LayerCache.LayerContours.Size; i++)
+                    {
+                        if ((int)LayerCache.LayerHierarchyJagged.GetValue(0, i, 2) == -1 &&
+                            (int)LayerCache.LayerHierarchyJagged.GetValue(0, i, 3) != -1) continue;
+                        CvInvoke.Rectangle(LayerCache.ImageBgr, CvInvoke.BoundingRectangle(LayerCache.LayerContours[i]),
+                            new MCvScalar(
+                                Settings.LayerPreview.ContourBoundsOutlineColor.B,
+                                Settings.LayerPreview.ContourBoundsOutlineColor.G, 
+                                Settings.LayerPreview.ContourBoundsOutlineColor.R),
+                            Settings.LayerPreview.ContourBoundsOutlineThickness);
+                    }
+                }
+
                 if (_showLayerOutlineHollowAreas)
                 {
                     //CvInvoke.Threshold(ActualLayerImage, grayscale, 1, 255, ThresholdType.Binary);
@@ -1009,6 +1049,34 @@ namespace UVtools.WPF
                     }
                 }
 
+                if (_showLayerOutlineCentroids)
+                {
+                    for (int i = 0; i < LayerCache.LayerContours.Size; i++)
+                    {
+                        if ((int)LayerCache.LayerHierarchyJagged.GetValue(0, i, 2) == -1 &&
+                            (int)LayerCache.LayerHierarchyJagged.GetValue(0, i, 3) != -1)
+                        {
+                            if (Settings.LayerPreview.CentroidOutlineHollow)
+                            {
+                                CvInvoke.Circle(LayerCache.ImageBgr, Contour.GetCentroid(LayerCache.LayerContours[i]),
+                                    Settings.LayerPreview.CentroidOutlineDiameter / 2, new MCvScalar(
+                                        Settings.LayerPreview.HollowOutlineColor.B,
+                                        Settings.LayerPreview.HollowOutlineColor.G,
+                                        Settings.LayerPreview.HollowOutlineColor.R), 1, LineType.AntiAlias);
+                            }
+                        }
+                        else
+                        {
+                            CvInvoke.Circle(LayerCache.ImageBgr, Contour.GetCentroid(LayerCache.LayerContours[i]),
+                                Settings.LayerPreview.CentroidOutlineDiameter / 2, new MCvScalar(
+                                    Settings.LayerPreview.CentroidOutlineColor.B,
+                                    Settings.LayerPreview.CentroidOutlineColor.G,
+                                    Settings.LayerPreview.CentroidOutlineColor.R), -1, LineType.AntiAlias);
+                        }
+                            
+                    }
+                }
+
                 if (_maskPoints is not null && _maskPoints.Count > 0)
                 {
                     using var vec = new VectorOfVectorOfPoint(_maskPoints.ToArray());
diff --git a/UVtools.WPF/MainWindow.axaml b/UVtools.WPF/MainWindow.axaml
index 6c98575..35fe48c 100644
--- a/UVtools.WPF/MainWindow.axaml
+++ b/UVtools.WPF/MainWindow.axaml
@@ -786,9 +786,39 @@
                   <CheckBox
                     IsChecked="{Binding Settings.Issues.ComputeOverhangs}"
                     Content="Overhangs"/>
-                  <CheckBox
-                    IsChecked="{Binding Settings.Issues.ComputeResinTraps}"
-                    Content="Resin traps"/>
+                  <StackPanel Orientation="Horizontal">
+                      <CheckBox
+                          VerticalAlignment="Center"
+                          IsChecked="{Binding Settings.Issues.ComputeResinTraps}"
+                          Content="Resin traps"/>
+
+                      <NumericUpDown
+                          VerticalAlignment="Center"
+                          Margin="10,0,0,0"
+                          ToolTip.Tip="Starting layer index for resin trap detection which will also be considered a drain layer.
+&#x0a;Use this setting to bypass complicated rafts by selected the model first real layer."
+                          Minimum="0"
+                          Maximum="{Binding SlicerFile.LastLayerIndex}"
+                          Increment="1"
+                          Width="110"
+                          Value="{Binding ResinTrapDetectionStartLayer}"/>
+
+                      <Button 
+                          VerticalAlignment="Center"
+                          Margin="2,0,0,0"
+                          ToolTip.Tip="Set to the first normal layer"
+                          Content="N"
+                          Command="{Binding SetResinTrapDetectionStartLayer}"
+                          CommandParameter="N"/>
+                      <Button 
+                          VerticalAlignment="Center"
+                          Margin="2,0,0,0"
+                          ToolTip.Tip="Set to the current layer"
+                          Content="C"
+                          Command="{Binding SetResinTrapDetectionStartLayer}"
+                          CommandParameter="C"/>
+                  </StackPanel>
+                  
                   <CheckBox
                     IsChecked="{Binding Settings.Issues.ComputeTouchingBounds}"
                     Content="Touching bounds"/>
@@ -1948,8 +1978,7 @@
             Command="{Binding OpenContextMenu}"
             CommandParameter="LayerPreviewOutline"
             VerticalAlignment="Stretch"
-            Margin="1,0,0,0"
-          >
+            Margin="1,0,0,0">
             <Button.ContextMenu>
               <ContextMenu Name="LayerPreviewOutlineContextMenu" PlacementMode="Bottom">
                 <CheckBox
@@ -1959,9 +1988,15 @@
                   IsChecked="{Binding ShowLayerOutlineLayerBoundary}"
                   Content="Layer boundary"/>
                 <CheckBox
+                     IsChecked="{Binding ShowLayerOutlineContourBoundary}"
+                     Content="Blob boundary"/>
+                <CheckBox
                   IsChecked="{Binding ShowLayerOutlineHollowAreas}"
                   Content="Hollow areas"/>
                 <CheckBox
+                    IsChecked="{Binding ShowLayerOutlineCentroids}"
+                    Content="Centroids"/>
+                <CheckBox
                   IsChecked="{Binding ShowLayerOutlineEdgeDetection}"
                   Content="Edge detection">
                   <CheckBox.IsEnabled>
diff --git a/UVtools.WPF/MainWindow.axaml.cs b/UVtools.WPF/MainWindow.axaml.cs
index 72ef210..efe024e 100644
--- a/UVtools.WPF/MainWindow.axaml.cs
+++ b/UVtools.WPF/MainWindow.axaml.cs
@@ -712,7 +712,7 @@ namespace UVtools.WPF
             {
                 ProcessFile(Path.Combine(App.ApplicationPath, About.DemoFile));
             }
-
+            
             DispatcherTimer.Run(() =>
             {
                 UpdateTitle();
@@ -967,6 +967,7 @@ namespace UVtools.WPF
 
             _actualLayer = 0;
             LayerCache.Clear();
+            _resinTrapDetectionStartLayer = 0;
 
             VisibleThumbnailIndex = 0;
 
@@ -1389,7 +1390,11 @@ namespace UVtools.WPF
                 _showLayerImageRotated = mat.Height > mat.Width;
             }
 
-            if (SlicerFile.DisplayMirror != Enumerations.FlipDirection.None)
+            if (SlicerFile.DisplayMirror == Enumerations.FlipDirection.None)
+            {
+                _showLayerImageFlipped = false;
+            }
+            else
             {
                 _showLayerImageFlipped = true;
                 _showLayerImageFlippedHorizontally = SlicerFile.DisplayMirror is Enumerations.FlipDirection.Horizontally or Enumerations.FlipDirection.Both;
diff --git a/UVtools.WPF/UVtools.WPF.csproj b/UVtools.WPF/UVtools.WPF.csproj
index fb90318..56a2dd8 100644
--- a/UVtools.WPF/UVtools.WPF.csproj
+++ b/UVtools.WPF/UVtools.WPF.csproj
@@ -12,7 +12,7 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <RepositoryUrl>https://github.com/sn4k3/UVtools</RepositoryUrl>
     <RepositoryType>Git</RepositoryType>
-    <Version>2.21.0</Version>
+    <Version>2.21.1</Version>
   </PropertyGroup>
   
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
diff --git a/UVtools.WPF/UserSettings.cs b/UVtools.WPF/UserSettings.cs
index b76150e..a1aa260 100644
--- a/UVtools.WPF/UserSettings.cs
+++ b/UVtools.WPF/UserSettings.cs
@@ -183,12 +183,19 @@ namespace UVtools.WPF
             private Color _volumeBoundsOutlineColor = new(255, 0, 255, 0);
             private byte _volumeBoundsOutlineThickness = 3;
             private bool _volumeBoundsOutline = true;
-            private Color _layerBoundsOutlineColor = new(255, 0, 255, 0);
+            private Color _layerBoundsOutlineColor = new(255, 45, 150, 45);
             private byte _layerBoundsOutlineThickness = 3;
             private bool _layerBoundsOutline = false;
+            private Color _contourBoundsOutlineColor = new(255, 50, 100, 50);
+            private byte _contourBoundsOutlineThickness = 2;
+            private bool _contourBoundsOutline = false;
             private Color _hollowOutlineColor = new(255, 255, 165, 0);
             private sbyte _hollowOutlineLineThickness = 5;
             private bool _hollowOutline = false;
+            private Color _centroidOutlineColor = new(255, 255, 0, 0);
+            private byte _centroidOutlineDiameter = 8;
+            private bool _centroidOutlineHollow = false;
+            private bool _centroidOutline = true;
             private Color _maskOutlineColor = new(255, 42, 157, 244);
             private sbyte _maskOutlineLineThickness = 10;
             private bool _maskClearRoiAfterSet = true;
@@ -298,6 +305,35 @@ namespace UVtools.WPF
                 set => RaiseAndSetIfChanged(ref _layerBoundsOutline, value);
             }
 
+            public Color ContourBoundsOutlineColor
+            {
+                get => _contourBoundsOutlineColor;
+                set
+                {
+                    RaiseAndSetIfChanged(ref _contourBoundsOutlineColor, value);
+                    RaisePropertyChanged(nameof(ContourBoundsOutlineBrush));
+                }
+            }
+
+            [XmlIgnore]
+            public SolidColorBrush ContourBoundsOutlineBrush
+            {
+                get => new(_contourBoundsOutlineColor.ToAvalonia());
+                set => ContourBoundsOutlineColor = new Color(value);
+            }
+
+            public byte ContourBoundsOutlineThickness
+            {
+                get => _contourBoundsOutlineThickness;
+                set => RaiseAndSetIfChanged(ref _contourBoundsOutlineThickness, value);
+            }
+
+            public bool ContourBoundsOutline
+            {
+                get => _contourBoundsOutline;
+                set => RaiseAndSetIfChanged(ref _contourBoundsOutline, value);
+            }
+
             public Color HollowOutlineColor
             {
                 get => _hollowOutlineColor;
@@ -327,6 +363,41 @@ namespace UVtools.WPF
                 set => RaiseAndSetIfChanged(ref _hollowOutline, value);
             }
 
+            public Color CentroidOutlineColor
+            {
+                get => _centroidOutlineColor;
+                set
+                {
+                    RaiseAndSetIfChanged(ref _centroidOutlineColor, value);
+                    RaisePropertyChanged(nameof(CentroidOutlineBrush));
+                }
+            }
+
+            [XmlIgnore]
+            public SolidColorBrush CentroidOutlineBrush
+            {
+                get => new(_centroidOutlineColor.ToAvalonia());
+                set => CentroidOutlineColor = new Color(value);
+            }
+
+            public byte CentroidOutlineDiameter
+            {
+                get => _centroidOutlineDiameter;
+                set => RaiseAndSetIfChanged(ref _centroidOutlineDiameter, value);
+            }
+
+            public bool CentroidOutlineHollow
+            {
+                get => _centroidOutlineHollow;
+                set => RaiseAndSetIfChanged(ref _centroidOutlineHollow, value);
+            }
+
+            public bool CentroidOutline
+            {
+                get => _centroidOutline;
+                set => RaiseAndSetIfChanged(ref _centroidOutline, value);
+            }
+
             public Color MaskOutlineColor
             {
                 get => _maskOutlineColor;
diff --git a/UVtools.WPF/Windows/SettingsWindow.axaml b/UVtools.WPF/Windows/SettingsWindow.axaml
index 6389676..325cf21 100644
--- a/UVtools.WPF/Windows/SettingsWindow.axaml
+++ b/UVtools.WPF/Windows/SettingsWindow.axaml
@@ -345,7 +345,7 @@
               <StackPanel Orientation="Vertical">
                 <TextBlock Padding="10" Background="LightBlue" FontWeight="Bold" Text="Layer colors"/>
 
-                <Grid Margin="10" RowDefinitions="Auto,10,Auto,10,Auto,10,Auto,10,Auto" ColumnDefinitions="Auto,Auto,Auto,Auto,*">
+                <Grid Margin="10" RowDefinitions="Auto,10,Auto,10,Auto,10,Auto,10,Auto,10,Auto,10,Auto" ColumnDefinitions="Auto,Auto,Auto,Auto,*">
 
                   <!--Tooltip overlay-->
                   <TextBlock Grid.Row="0" Grid.Column="0"
@@ -417,16 +417,14 @@
                            VerticalAlignment="Center"
                           Background="{Binding Settings.LayerPreview.LayerBoundsOutlineBrush}"
                           Command="{Binding SelectColor}"
-                          CommandParameter="LayerBoundsOutlineColor"
-                        />
+                          CommandParameter="LayerBoundsOutlineColor"/>
                   <NumericUpDown Grid.Row="4" Grid.Column="2"
                                  Margin="10,0,0,0"
                                  VerticalAlignment="Center"
                                  
                                  Minimum="1"
                                  Maximum="50"
-                                 Value="{Binding Settings.LayerPreview.LayerBoundsOutlineThickness}"
-                               />
+                                 Value="{Binding Settings.LayerPreview.LayerBoundsOutlineThickness}"/>
                   <TextBlock Grid.Row="4" Grid.Column="3"
                              Margin="5,0,0,0"
                              VerticalAlignment="Center"
@@ -436,15 +434,44 @@
                             HorizontalAlignment="Right"
                             VerticalAlignment="Center"
                             Content="Show by default"
-                            IsChecked="{Binding Settings.LayerPreview.LayerBoundsOutline}"
-                          />
+                            IsChecked="{Binding Settings.LayerPreview.LayerBoundsOutline}"/>
+
+                  <!--Blob boundary-->
+                  <TextBlock Grid.Row="6" Grid.Column="0"
+                             VerticalAlignment="Center"
+                             Text="Blob boundary:"/>
+                  <Button Grid.Row="6" Grid.Column="1"
+                          Margin="10,0,0,0"
+                          Padding="10"
+                          BorderBrush="Black"
+                          BorderThickness="2"
+                          VerticalAlignment="Center"
+                          Background="{Binding Settings.LayerPreview.ContourBoundsOutlineBrush}"
+                          Command="{Binding SelectColor}"
+                          CommandParameter="LayerBoundsOutlineColor"/>
+                  <NumericUpDown Grid.Row="6" Grid.Column="2"
+                                 Margin="10,0,0,0"
+                                 VerticalAlignment="Center"
+                                 Minimum="1"
+                                 Maximum="50"
+                                 Value="{Binding Settings.LayerPreview.ContourBoundsOutlineThickness}"/>
+                  <TextBlock Grid.Row="6" Grid.Column="3"
+                             Margin="5,0,0,0"
+                             VerticalAlignment="Center"
+                             Text="Line thickness"/>
+                  <CheckBox Grid.Row="6" Grid.Column="4"
+                            Margin="10,0,0,0"
+                            HorizontalAlignment="Right"
+                            VerticalAlignment="Center"
+                            Content="Show by default"
+                            IsChecked="{Binding Settings.LayerPreview.ContourBoundsOutline}"/>
 
 
                   <!--Hallow area boundary-->
-                  <TextBlock Grid.Row="6" Grid.Column="0"
+                  <TextBlock Grid.Row="8" Grid.Column="0"
                              VerticalAlignment="Center"
                              Text="Hollow area outline:"/>
-                  <Button Grid.Row="6" Grid.Column="1"
+                  <Button Grid.Row="8" Grid.Column="1"
                           Margin="10,0,0,0"
                           Padding="10"
                           BorderBrush="Black"
@@ -453,29 +480,65 @@
                           Background="{Binding Settings.LayerPreview.HollowOutlineBrush}"
                           Command="{Binding SelectColor}"
                           CommandParameter="HollowOutlineColor"/>
-                  <NumericUpDown Grid.Row="6" Grid.Column="2"
+                  <NumericUpDown Grid.Row="8" Grid.Column="2"
                                  Margin="10,0,0,0"
                                  VerticalAlignment="Center"
                                  Minimum="-1"
                                  Maximum="127"
                                  Value="{Binding Settings.LayerPreview.HollowOutlineLineThickness}"/>
-                  <TextBlock Grid.Row="6" Grid.Column="3"
+                  <TextBlock Grid.Row="8" Grid.Column="3"
                              Margin="5,0,0,0"
                              VerticalAlignment="Center"
                              ToolTip.Tip="Set -1 to fill the area"
                              Text="Line thickness"/>
-                  <CheckBox Grid.Row="6" Grid.Column="4"
+                  <CheckBox Grid.Row="8" Grid.Column="4"
                             Margin="10,0,0,0"
                             HorizontalAlignment="Right"
                             VerticalAlignment="Center"
                             Content="Show by default"
                             IsChecked="{Binding Settings.LayerPreview.HollowOutline}"/>
 
+                  <!--Blob boundary-->
+                  <TextBlock Grid.Row="10" Grid.Column="0"
+                             VerticalAlignment="Center"
+                             Text="Centroids:"/>
+                  <Button Grid.Row="10" Grid.Column="1"
+                          Margin="10,0,0,0"
+                          Padding="10"
+                          BorderBrush="Black"
+                          BorderThickness="2"
+                          VerticalAlignment="Center"
+                          Background="{Binding Settings.LayerPreview.CentroidOutlineBrush}"
+                          Command="{Binding SelectColor}"
+                          CommandParameter="LayerBoundsOutlineColor"/>
+                  <NumericUpDown Grid.Row="10" Grid.Column="2"
+                                 Margin="10,0,0,0"
+                                 VerticalAlignment="Center"
+                                 Minimum="1"
+                                 Maximum="50"
+                                 Value="{Binding Settings.LayerPreview.CentroidOutlineDiameter}"/>
+                  <TextBlock Grid.Row="10" Grid.Column="3"
+                             Margin="5,0,0,0"
+                             VerticalAlignment="Center"
+                             Text="Diameter"/>
+
+                  <StackPanel 
+                      HorizontalAlignment="Right"
+                      VerticalAlignment="Center"
+                      Grid.Row="10" Grid.Column="3" Grid.ColumnSpan="2" Orientation="Horizontal" Spacing="10">
+                      <CheckBox Content="Hollow centroids"
+                                IsChecked="{Binding Settings.LayerPreview.CentroidOutlineHollow}"/>
+
+                      <CheckBox Content="Show by default"
+                                IsChecked="{Binding Settings.LayerPreview.CentroidOutline}"/>
+                  </StackPanel>
+
+
                   <!--Masks-->
-                  <TextBlock Grid.Row="8" Grid.Column="0"
+                  <TextBlock Grid.Row="12" Grid.Column="0"
                              VerticalAlignment="Center"
                              Text="Mask area outline:"/>
-                  <Button Grid.Row="8" Grid.Column="1"
+                  <Button Grid.Row="12" Grid.Column="1"
                           Margin="10,0,0,0"
                           Padding="10"
                           BorderBrush="Black"
@@ -484,18 +547,18 @@
                           Background="{Binding Settings.LayerPreview.MaskOutlineBrush}"
                           Command="{Binding SelectColor}"
                           CommandParameter="MaskOutlineColor"/>
-                  <NumericUpDown Grid.Row="8" Grid.Column="2"
+                  <NumericUpDown Grid.Row="12" Grid.Column="2"
                                  Margin="10,0,0,0"
                                  VerticalAlignment="Center"
                                  Minimum="-1"
                                  Maximum="127"
                                  Value="{Binding Settings.LayerPreview.MaskOutlineLineThickness}"/>
-                  <TextBlock Grid.Row="8" Grid.Column="3"
+                  <TextBlock Grid.Row="12" Grid.Column="3"
                              Margin="5,0,0,0"
                              VerticalAlignment="Center"
                              ToolTip.Tip="Set -1 to fill the area"
                              Text="Line thickness"/>
-                  <CheckBox Grid.Row="8" Grid.Column="4"
+                  <CheckBox Grid.Row="12" Grid.Column="4"
                             Margin="10,0,0,0"
                             HorizontalAlignment="Right"
                             VerticalAlignment="Center"