From 6525ca10ef990e38a584d3f64b863c0d0e6a89d0 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Thu, 28 Jul 2016 18:08:51 +1000
Subject: [PATCH] Invert

Former-commit-id: 543588719050a2a824a61b3578bad8b1453937d4
Former-commit-id: 0e0ca33a0e82a2696f63609b1332c85949f42fda
Former-commit-id: 2750fc6e82392ec3c9368d9b2f062e8823ffb363
---
 src/ImageProcessorCore/Filters/Invert.cs      | 54 +++++++++++++++++++
 .../Filters/Processors/BrightnessProcessor.cs |  2 +-
 .../ColorMatrix/ColorMatrixFilter.cs          |  2 +-
 .../Filters/Processors/InvertProcessor.cs     | 54 +++++++++++++++++++
 .../Processors/Filters/InvertTest.cs          | 38 +++++++++++++
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 src/ImageProcessorCore/Filters/Invert.cs
 create mode 100644 src/ImageProcessorCore/Filters/Processors/InvertProcessor.cs
 create mode 100644 tests/ImageProcessorCore.Tests/Processors/Filters/InvertTest.cs

diff --git a/src/ImageProcessorCore/Filters/Invert.cs b/src/ImageProcessorCore/Filters/Invert.cs
new file mode 100644
index 0000000000..d7888be591
--- /dev/null
+++ b/src/ImageProcessorCore/Filters/Invert.cs
@@ -0,0 +1,54 @@
+// <copyright file="Invert.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>-------------------------------------------------------------------------------------------------------------------
+
+namespace ImageProcessorCore
+{
+    using Processors;
+
+    /// <summary>
+    /// Extension methods for the <see cref="Image"/> type.
+    /// </summary>
+    public static partial class ImageExtensions
+    {
+        /// <summary>
+        /// Inverts the colors of the image.
+        /// </summary>
+        /// <param name="source">The image this method extends.</param>
+        /// <param name="progressHandler">A delegate which is called as progress is made processing the image.</param>
+        /// <returns>The <see cref="Image"/>.</returns>
+        public static Image<T, TP> Invert<T, TP>(this Image<T, TP> source, ProgressEventHandler progressHandler = null)
+            where T : IPackedVector<TP>
+            where TP : struct
+        {
+            return Invert(source, source.Bounds, progressHandler);
+        }
+
+        /// <summary>
+        /// Inverts the colors of the image.
+        /// </summary>
+        /// <param name="source">The image this method extends.</param>
+        /// <param name="rectangle">
+        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
+        /// </param>
+        /// <param name="progressHandler">A delegate which is called as progress is made processing the image.</param>
+        /// <returns>The <see cref="Image"/>.</returns>
+        public static Image<T, TP> Invert<T, TP>(this Image<T, TP> source, Rectangle rectangle, ProgressEventHandler progressHandler = null)
+            where T : IPackedVector<TP>
+            where TP : struct
+        {
+            InvertProcessor<T, TP> processor = new InvertProcessor<T, TP>();
+            processor.OnProgress += progressHandler;
+
+            try
+            {
+                return source.Process(rectangle, processor);
+            }
+            finally
+            {
+                processor.OnProgress -= progressHandler;
+            }
+        }
+    }
+}
diff --git a/src/ImageProcessorCore/Filters/Processors/BrightnessProcessor.cs b/src/ImageProcessorCore/Filters/Processors/BrightnessProcessor.cs
index d253c4ebf0..3b3be22a51 100644
--- a/src/ImageProcessorCore/Filters/Processors/BrightnessProcessor.cs
+++ b/src/ImageProcessorCore/Filters/Processors/BrightnessProcessor.cs
@@ -60,7 +60,7 @@ namespace ImageProcessorCore.Processors
                                     Vector4 vector = sourcePixels[x, y].ToVector4().Expand();
                                     Vector3 transformed = new Vector3(vector.X, vector.Y, vector.Z);
                                     transformed += new Vector3(brightness);
-                                    vector = new Vector4(transformed.X, transformed.Y, transformed.Z, vector.W);
+                                    vector = new Vector4(transformed, vector.W);
 
                                     T packed = default(T);
                                     packed.PackVector(vector.Compress());
diff --git a/src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorMatrixFilter.cs b/src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorMatrixFilter.cs
index 3aeb33327f..47145c23ec 100644
--- a/src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorMatrixFilter.cs
+++ b/src/ImageProcessorCore/Filters/Processors/ColorMatrix/ColorMatrixFilter.cs
@@ -68,7 +68,7 @@ namespace ImageProcessorCore.Processors
             }
 
             Vector3 transformed = Vector3.Transform(new Vector3(vector.X, vector.Y, vector.Z), matrix);
-            vector = new Vector4(transformed.X, transformed.Y, transformed.Z, vector.W);
+            vector = new Vector4(transformed, vector.W);
             T packed = default(T);
             packed.PackVector(compand ? vector.Compress() : vector);
             return packed;
diff --git a/src/ImageProcessorCore/Filters/Processors/InvertProcessor.cs b/src/ImageProcessorCore/Filters/Processors/InvertProcessor.cs
new file mode 100644
index 0000000000..08cdb8f242
--- /dev/null
+++ b/src/ImageProcessorCore/Filters/Processors/InvertProcessor.cs
@@ -0,0 +1,54 @@
+// <copyright file="InvertProcessor.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Processors
+{
+    using System.Numerics;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// An <see cref="IImageProcessor"/> to invert the colors of an <see cref="Image"/>.
+    /// </summary>
+    public class InvertProcessor<T, TP> : ImageProcessor<T, TP>
+        where T : IPackedVector<TP>
+        where TP : struct
+    {
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase<T, TP> target, ImageBase<T, TP> source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
+        {
+            int sourceY = sourceRectangle.Y;
+            int sourceBottom = sourceRectangle.Bottom;
+            int startX = sourceRectangle.X;
+            int endX = sourceRectangle.Right;
+            Vector3 inverseVector = Vector3.One;
+
+            using (IPixelAccessor<T, TP> sourcePixels = source.Lock())
+            using (IPixelAccessor<T, TP> targetPixels = target.Lock())
+            {
+                Parallel.For(
+                    startY,
+                    endY,
+                    y =>
+                        {
+                            if (y >= sourceY && y < sourceBottom)
+                            {
+                                for (int x = startX; x < endX; x++)
+                                {
+                                    Vector4 color = sourcePixels[x, y].ToVector4();
+                                    Vector3 vector = inverseVector - new Vector3(color.X, color.Y, color.Z);
+
+                                    T packed = default(T);
+                                    packed.PackVector(new Vector4(vector, color.W));
+                                    targetPixels[x, y] = packed;
+                                }
+
+                                this.OnRowProcessed();
+                            }
+                        });
+            }
+        }
+    }
+}
+
diff --git a/tests/ImageProcessorCore.Tests/Processors/Filters/InvertTest.cs b/tests/ImageProcessorCore.Tests/Processors/Filters/InvertTest.cs
new file mode 100644
index 0000000000..14b589b3f6
--- /dev/null
+++ b/tests/ImageProcessorCore.Tests/Processors/Filters/InvertTest.cs
@@ -0,0 +1,38 @@
+// <copyright file="InvertTest.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Tests
+{
+    using System.IO;
+
+    using Xunit;
+
+    public class InvertTest : FileTestBase
+    {
+        [Fact]
+        public void ImageShouldApplyInvertFilter()
+        {
+            const string path = "TestOutput/Invert";
+            if (!Directory.Exists(path))
+            {
+                Directory.CreateDirectory(path);
+            }
+
+            foreach (string file in Files)
+            {
+                using (FileStream stream = File.OpenRead(file))
+                {
+                    string filename = Path.GetFileName(file);
+                    Image image = new Image(stream);
+                    using (FileStream output = File.OpenWrite($"{path}/{filename}"))
+                    {
+                        image.Invert()
+                             .Save(output);
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file