Bokeh blur implementation

src/ImageSharp/Color/Color.cs

@@ -2,8 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Buffers.Binary;
-using System.Globalization;
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;

src/ImageSharp/Common/Helpers/Buffer2DUtils.cs

@@ -0,0 +1,105 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+using SixLabors.ImageSharp.Memory;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Primitives;
+
+namespace SixLabors.ImageSharp
+{
+    /// <summary>
+    /// Extension methods for <see cref="Buffer2D{T}"/>.
+    /// TODO: One day rewrite all this to use SIMD intrinsics. There's a lot of scope for improvement.
+    /// </summary>
+    internal static class Buffer2DUtils
+    {
+        /// <summary>
+        /// Computes the sum of vectors in <paramref name="targetRow"/> weighted by the kernel weight values.
+        /// </summary>
+        /// <typeparam name="TPixel">The pixel format.</typeparam>
+        /// <param name="kernel">The 1D convolution kernel.</param>
+        /// <param name="sourcePixels">The source frame.</param>
+        /// <param name="targetRow">The target row.</param>
+        /// <param name="row">The current row.</param>
+        /// <param name="column">The current column.</param>
+        /// <param name="minRow">The minimum working area row.</param>
+        /// <param name="maxRow">The maximum working area row.</param>
+        /// <param name="minColumn">The minimum working area column.</param>
+        /// <param name="maxColumn">The maximum working area column.</param>
+        public static void Convolve4<TPixel>(
+            Span<Complex64> kernel,
+            Buffer2D<TPixel> sourcePixels,
+            Span<ComplexVector4> targetRow,
+            int row,
+            int column,
+            int minRow,
+            int maxRow,
+            int minColumn,
+            int maxColumn)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            ComplexVector4 vector = default;
+            int kernelLength = kernel.Length;
+            int radiusY = kernelLength >> 1;
+            int sourceOffsetColumnBase = column + minColumn;
+            ref Complex64 baseRef = ref MemoryMarshal.GetReference(kernel);
+
+            for (int i = 0; i < kernelLength; i++)
+            {
+                int offsetY = (row + i - radiusY).Clamp(minRow, maxRow);
+                int offsetX = sourceOffsetColumnBase.Clamp(minColumn, maxColumn);
+                Span<TPixel> sourceRowSpan = sourcePixels.GetRowSpan(offsetY);
+                var currentColor = sourceRowSpan[offsetX].ToVector4();
+
+                vector.Sum(Unsafe.Add(ref baseRef, i) * currentColor);
+            }
+
+            targetRow[column] = vector;
+        }
+
+        /// <summary>
+        /// Computes the sum of vectors in <paramref name="targetRow"/> weighted by the kernel weight values.
+        /// </summary>
+        /// <param name="kernel">The 1D convolution kernel.</param>
+        /// <param name="sourceValues">The source frame.</param>
+        /// <param name="targetRow">The target row.</param>
+        /// <param name="row">The current row.</param>
+        /// <param name="column">The current column.</param>
+        /// <param name="minRow">The minimum working area row.</param>
+        /// <param name="maxRow">The maximum working area row.</param>
+        /// <param name="minColumn">The minimum working area column.</param>
+        /// <param name="maxColumn">The maximum working area column.</param>
+        public static void Convolve4(
+            Span<Complex64> kernel,
+            Buffer2D<ComplexVector4> sourceValues,
+            Span<ComplexVector4> targetRow,
+            int row,
+            int column,
+            int minRow,
+            int maxRow,
+            int minColumn,
+            int maxColumn)
+        {
+            ComplexVector4 vector = default;
+            int kernelLength = kernel.Length;
+            int radiusX = kernelLength >> 1;
+            int sourceOffsetColumnBase = column + minColumn;
+
+            int offsetY = row.Clamp(minRow, maxRow);
+            ref ComplexVector4 sourceRef = ref MemoryMarshal.GetReference(sourceValues.GetRowSpan(offsetY));
+            ref Complex64 baseRef = ref MemoryMarshal.GetReference(kernel);
+
+            for (int x = 0; x < kernelLength; x++)
+            {
+                int offsetX = (sourceOffsetColumnBase + x - radiusX).Clamp(minColumn, maxColumn);
+                vector.Sum(Unsafe.Add(ref baseRef, x) * Unsafe.Add(ref sourceRef, offsetX));
+            }
+
+            targetRow[column] = vector;
+        }
+    }
+}

src/ImageSharp/Common/Helpers/DenseMatrixUtils.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -45,8 +45,6 @@ public static void Convolve2D3<TPixel>(
             int maxColumn)
             where TPixel : struct, IPixel<TPixel>
         {
-            Vector4 vector = default;
-
             Convolve2DImpl(
                 in matrixY,
                 in matrixX,
@@ -57,7 +55,7 @@ public static void Convolve2D3<TPixel>(
                 maxRow,
                 minColumn,
                 maxColumn,
-                ref vector);
+                out Vector4 vector);
 
             ref Vector4 target = ref Unsafe.Add(ref targetRowRef, column);
             vector.W = target.W;
@@ -95,8 +93,6 @@ public static void Convolve2D4<TPixel>(
             int maxColumn)
             where TPixel : struct, IPixel<TPixel>
         {
-            Vector4 vector = default;
-
             Convolve2DImpl(
                 in matrixY,
                 in matrixX,
@@ -107,7 +103,7 @@ public static void Convolve2D4<TPixel>(
                 maxRow,
                 minColumn,
                 maxColumn,
-                ref vector);
+                out Vector4 vector);
 
             ref Vector4 target = ref Unsafe.Add(ref targetRowRef, column);
             Vector4Utils.UnPremultiply(ref vector);
@@ -125,7 +121,7 @@ public static void Convolve2DImpl<TPixel>(
             int maxRow,
             int minColumn,
             int maxColumn,
-            ref Vector4 vector)
+            out Vector4 vector)
             where TPixel : struct, IPixel<TPixel>
         {
             Vector4 vectorY = default;
@@ -281,4 +277,4 @@ private static void ConvolveImpl<TPixel>(
             }
         }
     }
-}
+}

src/ImageSharp/Common/Helpers/SimdUtils.BasicIntrinsics256.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Diagnostics;
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;

src/ImageSharp/Common/Helpers/SimdUtils.cs

@@ -7,9 +7,6 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
-using SixLabors.ImageSharp.PixelFormats;
-using SixLabors.ImageSharp.Tuples;
-
 namespace SixLabors.ImageSharp
 {
     /// <summary>

src/ImageSharp/Formats/Jpeg/Components/Decoder/IRawJpegData.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Collections.Generic;
 
 using SixLabors.Primitives;
 

src/ImageSharp/Formats/Jpeg/Components/Encoder/YCbCrForwardConverter{TPixel}.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Runtime.CompilerServices;
 
-using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder

src/ImageSharp/Formats/Jpeg/Components/GenericBlock8x8.cs

@@ -7,7 +7,6 @@
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
-using SixLabors.Memory;
 
 // ReSharper disable InconsistentNaming
 namespace SixLabors.ImageSharp.Formats.Jpeg.Components

src/ImageSharp/Memory/Buffer2DExtensions.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Buffers;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;

src/ImageSharp/Memory/Buffer2D{T}.cs

@@ -61,13 +61,31 @@ public Buffer2D(MemorySource<T> memorySource, int width, int height)
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             get
             {
-                ImageSharp.DebugGuard.MustBeLessThan(x, this.Width, nameof(x));
-                ImageSharp.DebugGuard.MustBeLessThan(y, this.Height, nameof(y));
+                DebugGuard.MustBeLessThan(x, this.Width, nameof(x));
+                DebugGuard.MustBeLessThan(y, this.Height, nameof(y));
+
                 Span<T> span = this.Span;
                 return ref span[(this.Width * y) + x];
             }
         }
 
+        /// <summary>
+        /// Creates a new <see cref="Buffer2D{T}"/> instance that maps to a target rows interval from the current instance.
+        /// </summary>
+        /// <param name="y">The target vertical offset for the rows interval to retrieve.</param>
+        /// <param name="h">The desired number of rows to extract.</param>
+        /// <returns>The new <see cref="Buffer2D{T}"/> instance with the requested rows interval.</returns>
+        public Buffer2D<T> Slice(int y, int h)
+        {
+            DebugGuard.MustBeGreaterThanOrEqualTo(y, 0, nameof(y));
+            DebugGuard.MustBeGreaterThan(h, 0, nameof(h));
+            DebugGuard.MustBeLessThanOrEqualTo(y + h, this.Height, nameof(h));
+
+            Memory<T> slice = this.Memory.Slice(y * this.Width, h * this.Width);
+            var memory = new MemorySource<T>(slice);
+            return new Buffer2D<T>(memory, this.Width, h);
+        }
+
         /// <summary>
         /// Disposes the <see cref="Buffer2D{T}"/> instance
         /// </summary>
@@ -98,4 +116,4 @@ private static void SwapDimensionData(Buffer2D<T> a, Buffer2D<T> b)
             a.Height = bSize.Height;
         }
     }
-}
+}

src/ImageSharp/MetaData/Profiles/ICC/DataReader/IccDataReader.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
-using System.Text;
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Icc
 {

src/ImageSharp/PixelFormats/PixelImplementations/Gray16.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System;
 using System.Numerics;
 using System.Runtime.CompilerServices;
 

src/ImageSharp/PixelFormats/PixelImplementations/Rgba32.PixelOperations.cs

@@ -6,7 +6,6 @@
 using System.Runtime.InteropServices;
 
 using SixLabors.ImageSharp.PixelFormats.Utils;
-using SixLabors.Memory;
 
 namespace SixLabors.ImageSharp.PixelFormats
 {

src/ImageSharp/PixelFormats/PixelOperations{TPixel}.cs

@@ -4,8 +4,6 @@
 using System;
 using System.Buffers;
 using System.Numerics;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
 
 using SixLabors.ImageSharp.Memory;
 

src/ImageSharp/PixelFormats/Utils/Vector4Converters.Default.cs

@@ -6,8 +6,6 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
-using SixLabors.ImageSharp.ColorSpaces.Companding;
-
 namespace SixLabors.ImageSharp.PixelFormats.Utils
 {
     /// <summary>

src/ImageSharp/PixelFormats/Utils/Vector4Converters.RgbaCompatible.cs

@@ -7,8 +7,6 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
-using SixLabors.ImageSharp.ColorSpaces.Companding;
-
 namespace SixLabors.ImageSharp.PixelFormats.Utils
 {
     /// <content>