Add brightness

Former-commit-id: 0ccb55b3b1d634cbdf289c4496006174d8e382dc
Former-commit-id: ea1ba7bbf746e2cf0833e591e451b6ca4df78458
Former-commit-id: 1a6addaf532b4a547bd84d37d74db7198d940d30

src/ImageProcessor/Filters/Brightness.cs

@@ -0,0 +1,77 @@
+// <copyright file="Brightness.cs" company="James South">
+// Copyright (c) James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    using System;
+    using System.Numerics;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// An <see cref="IImageProcessor"/> to change the brightness of an <see cref="Image"/>.
+    /// </summary>
+    public class Brightness : ParallelImageProcessor
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Brightness"/> class.
+        /// </summary>
+        /// <param name="brightness">The new brightness of the image. Must be between -100 and 100.</param>
+        /// <exception cref="ArgumentException">
+        /// <paramref name="brightness"/> is less than -100 or is greater than 100.
+        /// </exception>
+        public Brightness(int brightness)
+        {
+            Guard.MustBeBetweenOrEqualTo(brightness, -100, 100, nameof(brightness));
+            this.Value = brightness;
+        }
+
+        /// <summary>
+        /// Gets the brightness value.
+        /// </summary>
+        public int Value { get; }
+
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
+        {
+            float brightness = this.Value / 100f;
+            int sourceY = sourceRectangle.Y;
+            int sourceBottom = sourceRectangle.Bottom;
+            int startX = sourceRectangle.X;
+            int endX = sourceRectangle.Right;
+
+            Parallel.For(
+                startY,
+                endY,
+                y =>
+                    {
+                        if (y >= sourceY && y < sourceBottom)
+                        {
+                            for (int x = startX; x < endX; x++)
+                            {
+                                target[x, y] = AdjustBrightness(source[x, y], brightness);
+                            }
+                        }
+                    });
+        }
+
+        /// <summary>
+        /// Returns a <see cref="Color"/> with the brightness adjusted.
+        /// </summary>
+        /// <param name="color">The source color.</param>
+        /// <param name="brightness">The brightness adjustment factor.</param>
+        /// <returns>
+        /// The <see cref="Color"/>.
+        /// </returns>
+        private static Color AdjustBrightness(Color color, float brightness)
+        {
+            color = PixelOperations.ToLinear(color);
+
+            Vector3 vector3 = color.ToVector3();
+            vector3 += new Vector3(brightness, brightness, brightness);
+
+            return PixelOperations.ToSrgb(new Color(vector3, color.A));
+        }
+    }
+}

src/ImageProcessor/Filters/ColorMatrix/ColorMatrix.cs

@@ -8,7 +8,7 @@
 namespace ImageProcessor.Filters
 {
     /// <summary>
-    /// Defines a 5 x 5 matrix that contains the coordinates for the RGBAW color space. 
+    /// Defines a 5x5 matrix that contains the coordinates for the RGBAW color space.
     /// </summary>
     public sealed class ColorMatrix
     {

src/ImageProcessor/Filters/Contrast.cs

@@ -67,6 +67,7 @@ namespace ImageProcessor.Filters
         {
             color = PixelOperations.ToLinear(color);
 
+            // Seems to be faster than Vector3.
             color.R -= 0.5f;
             color.R *= contrast;
             color.R += 0.5f;

src/ImageProcessor/Filters/Saturation.cs

@@ -0,0 +1,78 @@
+// <copyright file="Saturation.cs" company="James South">
+// Copyright (c) James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    using System;
+    using System.Numerics;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// An <see cref="IImageProcessor"/> to change the saturation of an <see cref="Image"/>.
+    /// </summary>
+    public class Saturation : ParallelImageProcessor
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Saturation"/> class.
+        /// </summary>
+        /// <param name="saturation">The new saturation of the image. Must be between -100 and 100.</param>
+        /// <exception cref="ArgumentException">
+        /// <paramref name="saturation"/> is less than -100 or is greater than 100.
+        /// </exception>
+        public Saturation(int saturation)
+        {
+            Guard.MustBeBetweenOrEqualTo(saturation, -100, 100, nameof(saturation));
+            this.Value = saturation;
+        }
+
+        /// <summary>
+        /// Gets the saturation value.
+        /// </summary>
+        public int Value { get; }
+
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
+        {
+            float saturation = this.Value / 100f;
+            int sourceY = sourceRectangle.Y;
+            int sourceBottom = sourceRectangle.Bottom;
+            int startX = sourceRectangle.X;
+            int endX = sourceRectangle.Right;
+
+            Parallel.For(
+                startY,
+                endY,
+                y =>
+                    {
+                        if (y >= sourceY && y < sourceBottom)
+                        {
+                            for (int x = startX; x < endX; x++)
+                            {
+                                target[x, y] = AdjustSaturation(source[x, y], saturation);
+                            }
+                        }
+                    });
+        }
+
+        /// <summary>
+        /// Returns a <see cref="Color"/> with the saturation adjusted.
+        /// </summary>
+        /// <param name="color">The source color.</param>
+        /// <param name="saturation">The saturation adjustment factor.</param>
+        /// <returns>
+        /// The <see cref="Color"/>.
+        /// </returns>
+        private static Color AdjustSaturation(Color color, float saturation)
+        {
+            //color = PixelOperations.ToLinear(color);
+
+            // TODO: This can be done with a matrix. But why can I not get conversion to work?
+            Hsv hsv = color;
+            return new Hsv(hsv.H, saturation, hsv.V);
+
+            //return PixelOperations.ToSrgb(newHsv);
+        }
+    }
+}

src/ImageProcessor/ImageProcessor.csproj

@@ -48,6 +48,9 @@
     <Compile Include="Common\Extensions\EnumerableExtensions.cs" />
     <Compile Include="Common\Helpers\ImageMaths.cs" />
     <Compile Include="Common\Helpers\PixelOperations.cs" />
+    <Compile Include="Filters\Saturation.cs" />
+    <Compile Include="Filters\ColorMatrix\GreyscaleMode.cs" />
+    <Compile Include="Filters\Brightness.cs" />
     <Compile Include="Filters\Invert.cs" />
     <Compile Include="Filters\Alpha.cs" />
     <Compile Include="Filters\ColorMatrix\ColorMatrix.cs" />

tests/ImageProcessor.Tests/Processors/Filters/FilterTests.cs

@@ -12,16 +12,20 @@ namespace ImageProcessor.Tests
     {
         public static readonly TheoryData<string, IImageProcessor> Filters = new TheoryData<string, IImageProcessor>
         {
+            //{ "Brightness-50", new Brightness(50) },
+            //{ "Brightness--50", new Brightness(-50) },
             //{ "Contrast-50", new Contrast(50) },
             //{ "Contrast--50", new Contrast(-50) },
+            { "Saturation-100", new Saturation(100) },
+            { "Saturation--0", new Saturation(0) },
             //{ "Alpha--50", new Alpha(50) },
-            { "Invert", new Invert() },
-            { "Sepia", new Sepia() },
-            { "BlackWhite", new BlackWhite() },
-            { "Lomograph", new Lomograph() },
-            { "Polaroid", new Polaroid() },
-            { "GreyscaleBt709", new GreyscaleBt709() },
-            { "GreyscaleBt601", new GreyscaleBt601() },
+            //{ "Invert", new Invert() },
+            //{ "Sepia", new Sepia() },
+            //{ "BlackWhite", new BlackWhite() },
+            //{ "Lomograph", new Lomograph() },
+            //{ "Polaroid", new Polaroid() },
+            //{ "GreyscaleBt709", new GreyscaleBt709() },
+            //{ "GreyscaleBt601", new GreyscaleBt601() },
         };
 
         [Theory]