Remove conditionals from loop and enforce equal matrice dimensions.

src/ImageSharp/Common/Helpers/DenseMatrixUtils.cs

@@ -42,6 +42,7 @@ namespace SixLabors.ImageSharp
             int matrixWidth = matrix.Columns;
             int radiusY = matrixHeight >> 1;
             int radiusX = matrixWidth >> 1;
+            int sourceOffsetColumnBase = column + offsetColumn;
 
             for (int y = 0; y < matrixHeight; y++)
             {
@@ -50,11 +51,11 @@ namespace SixLabors.ImageSharp
 
                 for (int x = 0; x < matrixWidth; x++)
                 {
-                    int offsetX = (column + offsetColumn + x - radiusX).Clamp(offsetColumn, maxColumn);
+                    int offsetX = (sourceOffsetColumnBase + x - radiusX).Clamp(offsetColumn, maxColumn);
                     var currentColor = sourceRowSpan[offsetX].ToVector4();
                     Vector4Utils.Premultiply(ref currentColor);
-                    currentColor *= matrix[y, x];
-                    vector += currentColor;
+
+                    vector += matrix[y, x] * currentColor;
                 }
             }
 
@@ -91,33 +92,25 @@ namespace SixLabors.ImageSharp
         {
             Vector4 vectorY = default;
             Vector4 vectorX = default;
-            int matrixYHeight = matrixY.Rows;
-            int matrixYWidth = matrixY.Columns;
-            int matrixXHeight = matrixX.Rows;
-            int matrixXWidth = matrixX.Columns;
-            int radiusY = matrixYHeight >> 1;
-            int radiusX = matrixXWidth >> 1;
+            int matrixHeight = matrixY.Rows;
+            int matrixWidth = matrixY.Columns;
+            int radiusY = matrixHeight >> 1;
+            int radiusX = matrixWidth >> 1;
+            int sourceOffsetColumnBase = column + offsetColumn;
 
-            for (int y = 0; y < matrixYHeight; y++)
+            for (int y = 0; y < matrixHeight; y++)
             {
                 int offsetY = (row + y - radiusY).Clamp(0, maxRow);
                 Span<TPixel> sourceRowSpan = sourcePixels.GetRowSpan(offsetY);
 
-                for (int x = 0; x < matrixXWidth; x++)
+                for (int x = 0; x < matrixWidth; x++)
                 {
-                    int offsetX = (column + offsetColumn + x - radiusX).Clamp(offsetColumn, maxColumn);
+                    int offsetX = (sourceOffsetColumnBase + x - radiusX).Clamp(offsetColumn, maxColumn);
                     var currentColor = sourceRowSpan[offsetX].ToVector4();
                     Vector4Utils.Premultiply(ref currentColor);
 
-                    if (y < matrixXHeight)
-                    {
-                        vectorX += matrixX[y, x] * currentColor;
-                    }
-
-                    if (x < matrixYWidth)
-                    {
-                        vectorY += matrixY[y, x] * currentColor;
-                    }
+                    vectorX += matrixX[y, x] * currentColor;
+                    vectorY += matrixY[y, x] * currentColor;
                 }
             }
 

src/ImageSharp/Primitives/DenseMatrix{T}.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using SixLabors.Primitives;
 
 namespace SixLabors.ImageSharp.Primitives
 {
@@ -31,6 +32,11 @@ namespace SixLabors.ImageSharp.Primitives
         /// </summary>
         public readonly int Rows;
 
+        /// <summary>
+        /// Gets the size of the dense matrix.
+        /// </summary>
+        public readonly Size Size;
+
         /// <summary>
         /// Gets the number of items in the array.
         /// </summary>
@@ -57,6 +63,7 @@ namespace SixLabors.ImageSharp.Primitives
 
             this.Rows = rows;
             this.Columns = columns;
+            this.Size = new Size(columns, rows);
             this.Count = columns * rows;
             this.Data = new T[this.Columns * this.Rows];
         }
@@ -76,6 +83,7 @@ namespace SixLabors.ImageSharp.Primitives
 
             this.Rows = rows;
             this.Columns = columns;
+            this.Size = new Size(columns, rows);
             this.Count = this.Columns * this.Rows;
             this.Data = new T[this.Columns * this.Rows];
 

src/ImageSharp/Processing/Processors/Convolution/Convolution2DProcessor.cs

@@ -25,6 +25,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
         /// <param name="kernelY">The vertical gradient operator.</param>
         public Convolution2DProcessor(DenseMatrix<float> kernelX, DenseMatrix<float> kernelY)
         {
+            Guard.IsTrue(kernelX.Size.Equals(kernelY.Size), $"{nameof(kernelX)} {nameof(kernelY)}", "Kernel sizes must be the same.");
             this.KernelX = kernelX;
             this.KernelY = kernelY;
         }

src/ImageSharp/Processing/Processors/Convolution/EdgeDetector2DProcessor.cs

@@ -23,6 +23,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
         /// <param name="grayscale">Whether to convert the image to grayscale before performing edge detection.</param>
         protected EdgeDetector2DProcessor(DenseMatrix<float> kernelX, DenseMatrix<float> kernelY, bool grayscale)
         {
+            Guard.IsTrue(kernelX.Size.Equals(kernelY.Size), $"{nameof(kernelX)} {nameof(kernelY)}", "Kernel sizes must be the same.");
             this.KernelX = kernelX;
             this.KernelY = kernelY;
             this.Grayscale = grayscale;
@@ -42,10 +43,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
         public bool Grayscale { get; set; }
 
         /// <inheritdoc />
-        protected override void OnFrameApply(ImageFrame<TPixel> source, Rectangle sourceRectangle, Configuration configuration)
-        {
-            new Convolution2DProcessor<TPixel>(this.KernelX, this.KernelY).Apply(source, sourceRectangle, configuration);
-        }
+        protected override void OnFrameApply(ImageFrame<TPixel> source, Rectangle sourceRectangle, Configuration configuration) => new Convolution2DProcessor<TPixel>(this.KernelX, this.KernelY).Apply(source, sourceRectangle, configuration);
 
         /// <inheritdoc/>
         protected override void BeforeFrameApply(ImageFrame<TPixel> source, Rectangle sourceRectangle, Configuration configuration)

tests/ImageSharp.Tests/Primitives/DenseMatrixTests.cs

@@ -3,6 +3,7 @@
 
 using System;
 using SixLabors.ImageSharp.Primitives;
+using SixLabors.Primitives;
 using Xunit;
 
 namespace SixLabors.ImageSharp.Tests.Primitives
@@ -59,6 +60,7 @@ namespace SixLabors.ImageSharp.Tests.Primitives
             Assert.True(dense.Rows == FloydSteinbergMatrix.GetLength(0));
             Assert.Equal(3, dense.Columns);
             Assert.Equal(2, dense.Rows);
+            Assert.Equal(new Size(3, 2), dense.Size);
         }
 
         [Fact]