diff --git a/UVtools.Core/Extensions/EmguExtensions.cs b/UVtools.Core/Extensions/EmguExtensions.cs
index a21ca9c..7b4577e 100644
--- a/UVtools.Core/Extensions/EmguExtensions.cs
+++ b/UVtools.Core/Extensions/EmguExtensions.cs
@@ -67,6 +67,14 @@ namespace UVtools.Core.Extensions
         public static Mat NewBlank(this Mat mat)
             => InitMat(mat.Size, mat.NumberOfChannels, mat.Depth);
 
+        /// <summary>
+        /// Creates a new blanked (All zeros) <see cref="UMat"/> with same size and type of the source
+        /// </summary>
+        /// <param name="mat"></param>
+        /// <returns>Blanked <see cref="Mat"/></returns>
+        public static UMat NewBlank(this UMat mat)
+            => InitUMat(mat.Size, mat.NumberOfChannels, mat.Depth);
+
         /// <summary>
         /// Creates a <see cref="Mat"/> with same size and type of the source and set it to a color
         /// </summary>
@@ -87,6 +95,21 @@ namespace UVtools.Core.Extensions
         public static Mat InitMat(Size size, int channels = 1, DepthType depthType = DepthType.Cv8U)
             => size.IsEmpty ? new() : Mat.Zeros(size.Height, size.Width, depthType, channels);
 
+        /// <summary>
+        /// Creates a new <see cref="UMat"/> and zero it
+        /// </summary>
+        /// <param name="size"></param>
+        /// <param name="channels"></param>
+        /// <param name="depthType"></param>
+        /// <returns></returns>
+        public static UMat InitUMat(Size size, int channels = 1, DepthType depthType = DepthType.Cv8U)
+        {
+            if (size.IsEmpty) return new();
+            var umat = new UMat(size.Height, size.Width, depthType, channels);
+            umat.SetTo(BlackColor);
+            return umat;
+        }
+
         /// <summary>
         /// Creates a new <see cref="Mat"/> and set it to a <see cref="MCvScalar"/>
         /// </summary>
diff --git a/UVtools.Core/Layer/LayerManager.cs b/UVtools.Core/Layer/LayerManager.cs
index b718767..1e7449c 100644
--- a/UVtools.Core/Layer/LayerManager.cs
+++ b/UVtools.Core/Layer/LayerManager.cs
@@ -775,7 +775,7 @@ namespace UVtools.Core
                 return true;
             }
 
-            void GenerateAirMap(Mat input, Mat output, VectorOfVectorOfPoint externals)
+            void GenerateAirMap(IInputArray input, IInputOutputArray output, VectorOfVectorOfPoint externals)
             {
                 CvInvoke.BitwiseNot(input, output); 
                 if (externals is null || externals.Size == 0) return;