Add ColorMatrix functionality

Former-commit-id: 741ed5325553c7e521375e2b6168cfd345fe69d5 Former-commit-id: f290ab071672406c5f3d846cedea2e7c280329c0 Former-commit-id: 1ca475830cd7732a17fb3f407418189aea692e8e
10 years ago · 5e0d0de329
16 changed files with 674 additions and 4 deletions
--- a/src/ImageProcessor/Filters/ColorMatrix/BlackWhite.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/BlackWhite.cs
@ -0,0 +1,35 @@
+// <copyright file="BlackWhite.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image to their black and white equivalent.
+    /// </summary>
+    public class BlackWhite : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The BlackWhite matrix.
+        /// TODO: Calculate a matrix that works in the linear color space.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new[] { 1.5f, 1.5f, 1.5f, 0, 0 },
+                    new[] { 1.5f, 1.5f, 1.5f, 0, 0 },
+                    new[] { 1.5f, 1.5f, 1.5f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new float[] { -1, -1, -1, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BlackWhite"/> class.
+        /// </summary>
+        public BlackWhite()
+            : base(Matrix, false)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/ColorMatrix.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/ColorMatrix.cs
@ -0,0 +1,273 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="ColorMatrix.cs" company="James South">
+//   Copyright © James South and contributors.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Defines a 5 x 5 matrix that contains the coordinates for the RGBAW color space. 
+    /// </summary>
+    public sealed class ColorMatrix
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ColorMatrix"/> class.
+        /// </summary>
+        public ColorMatrix()
+        {
+            // Setup the identity matrix by default
+            this.Matrix00 = 1.0f;
+            this.Matrix11 = 1.0f;
+            this.Matrix22 = 1.0f;
+            this.Matrix33 = 1.0f;
+            this.Matrix44 = 1.0f;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ColorMatrix"/> class with the
+        /// elements in the specified matrix.
+        /// </summary>
+        /// <param name="colorMatrix">
+        /// The elements defining the new Color Matrix.
+        /// </param>
+        public ColorMatrix(float[][] colorMatrix)
+        {
+            this.SetMatrix(colorMatrix);
+        }
+
+        /// <summary>
+        /// Gets or sets the element at the 0th row and 0th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix00 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 0th row and 1st column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix01 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 0th row and 2nd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix02 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 0th row and 3rd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix03 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 0th row and 4th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix04 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 1st row and 0th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix10 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 1st row and 1st column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix11 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 1st row and 2nd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix12 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 1st row and 3rd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix13 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 1st row and 4th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix14 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 2nd row and 0th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix20 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 2nd row and 1st column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix21 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 2nd row and 2nd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix22 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 2nd row and 3rd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix23 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 2nd row and 4th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix24 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 3rd row and 0th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix30 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 3rd row and 1st column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix31 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 3rd row and 2nd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix32 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 3rd row and 3rd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix33 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 3rd row and 4th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix34 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 4th row and 0th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix40 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 4th row and 1st column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix41 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 4th row and 2nd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix42 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 4th row and 3rd column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix43 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the element at the 4th row and 4th column of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        public float Matrix44 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the value of the specified element of this <see cref="ColorMatrix"/>.
+        /// </summary>
+        /// <param name="row">
+        /// The row index.
+        /// </param>
+        /// <param name="column">
+        /// The column index.
+        /// </param>
+        /// <returns>
+        /// The <see cref="float"/>.
+        /// </returns>
+        public float this[int row, int column]
+        {
+            get
+            {
+                return this.GetMatrix()[row][column];
+            }
+
+            set
+            {
+                float[][] tempMatrix = this.GetMatrix();
+
+                tempMatrix[row][column] = value;
+
+                this.SetMatrix(tempMatrix);
+            }
+        }
+
+        /// <summary>
+        /// Sets the values of this <see cref="ColorMatrix"/> to the values contained within the elements.
+        /// </summary>
+        /// <param name="colorMatrix">
+        /// The new color matrix.
+        /// </param>
+        internal void SetMatrix(float[][] colorMatrix)
+        {
+            this.Matrix00 = colorMatrix[0][0];
+            this.Matrix01 = colorMatrix[0][1];
+            this.Matrix02 = colorMatrix[0][2];
+            this.Matrix03 = colorMatrix[0][3];
+            this.Matrix04 = colorMatrix[0][4];
+            this.Matrix10 = colorMatrix[1][0];
+            this.Matrix11 = colorMatrix[1][1];
+            this.Matrix12 = colorMatrix[1][2];
+            this.Matrix13 = colorMatrix[1][3];
+            this.Matrix14 = colorMatrix[1][4];
+            this.Matrix20 = colorMatrix[2][0];
+            this.Matrix21 = colorMatrix[2][1];
+            this.Matrix22 = colorMatrix[2][2];
+            this.Matrix23 = colorMatrix[2][3];
+            this.Matrix24 = colorMatrix[2][4];
+            this.Matrix30 = colorMatrix[3][0];
+            this.Matrix31 = colorMatrix[3][1];
+            this.Matrix32 = colorMatrix[3][2];
+            this.Matrix33 = colorMatrix[3][3];
+            this.Matrix34 = colorMatrix[3][4];
+            this.Matrix40 = colorMatrix[4][0];
+            this.Matrix41 = colorMatrix[4][1];
+            this.Matrix42 = colorMatrix[4][2];
+            this.Matrix43 = colorMatrix[4][3];
+            this.Matrix44 = colorMatrix[4][4];
+        }
+
+        /// <summary>
+        /// Gets this <see cref="ColorMatrix"/>.
+        /// </summary>
+        /// <returns>
+        /// The <see cref="T:float[][]"/>.
+        /// </returns>
+        internal float[][] GetMatrix()
+        {
+            float[][] returnMatrix = new float[5][];
+
+            for (int i = 0; i < 5; i++)
+            {
+                returnMatrix[i] = new float[5];
+            }
+
+            returnMatrix[0][0] = this.Matrix00;
+            returnMatrix[0][1] = this.Matrix01;
+            returnMatrix[0][2] = this.Matrix02;
+            returnMatrix[0][3] = this.Matrix03;
+            returnMatrix[0][4] = this.Matrix04;
+            returnMatrix[1][0] = this.Matrix10;
+            returnMatrix[1][1] = this.Matrix11;
+            returnMatrix[1][2] = this.Matrix12;
+            returnMatrix[1][3] = this.Matrix13;
+            returnMatrix[1][4] = this.Matrix14;
+            returnMatrix[2][0] = this.Matrix20;
+            returnMatrix[2][1] = this.Matrix21;
+            returnMatrix[2][2] = this.Matrix22;
+            returnMatrix[2][3] = this.Matrix23;
+            returnMatrix[2][4] = this.Matrix24;
+            returnMatrix[3][0] = this.Matrix30;
+            returnMatrix[3][1] = this.Matrix31;
+            returnMatrix[3][2] = this.Matrix32;
+            returnMatrix[3][3] = this.Matrix33;
+            returnMatrix[3][4] = this.Matrix34;
+            returnMatrix[4][0] = this.Matrix40;
+            returnMatrix[4][1] = this.Matrix41;
+            returnMatrix[4][2] = this.Matrix42;
+            returnMatrix[4][3] = this.Matrix43;
+            returnMatrix[4][4] = this.Matrix44;
+
+            return returnMatrix;
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/ColorMatrixFilter.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/ColorMatrixFilter.cs
@ -0,0 +1,101 @@
+// <copyright file="ColorMatrixFilter.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// The color matrix filter.
+    /// </summary>
+    public class ColorMatrixFilter : ParallelImageProcessor
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ColorMatrixFilter"/> class.
+        /// </summary>
+        /// <param name="matrix">The matrix to apply.</param>
+        /// <param name="gammaAdjust">Whether to gamma adjust the colors before applying the matrix.</param>
+        public ColorMatrixFilter(ColorMatrix matrix, bool gammaAdjust)
+        {
+            this.Value = matrix;
+            this.GammaAdjust = gammaAdjust;
+        }
+
+        /// <summary>
+        /// Gets the matrix value.
+        /// </summary>
+        public ColorMatrix Value { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether to gamma adjust the colors before applying the matrix.
+        /// </summary>
+        public bool GammaAdjust { get; }
+
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase target, ImageBase 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;
+            ColorMatrix matrix = this.Value;
+            Bgra previousColor = source[0, 0];
+            Bgra pixelValue = this.ApplyMatrix(previousColor, matrix);
+
+            for (int y = startY; y < endY; y++)
+            {
+                if (y >= sourceY && y < sourceBottom)
+                {
+                    for (int x = startX; x < endX; x++)
+                    {
+                        Bgra sourceColor = source[x, y];
+
+                        // Check if this is the same as the last pixel. If so use that value
+                        // rather than calculating it again. This is an inexpensive optimization.
+                        if (sourceColor != previousColor)
+                        {
+                            // Perform the operation on the pixel.
+                            pixelValue = this.ApplyMatrix(sourceColor, matrix);
+
+                            // And setup the previous pointer
+                            previousColor = sourceColor;
+                        }
+
+                        target[x, y] = pixelValue;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Applies the color matrix against the given color.
+        /// </summary>
+        /// <param name="sourceColor">The source color.</param>
+        /// <param name="matrix">The matrix.</param>
+        /// <returns>
+        /// The <see cref="Bgra"/>.
+        /// </returns>
+        private Bgra ApplyMatrix(Bgra sourceColor, ColorMatrix matrix)
+        {
+            bool gamma = this.GammaAdjust;
+
+            if (gamma)
+            {
+                sourceColor = PixelOperations.ToLinear(sourceColor);
+            }
+
+            int sr = sourceColor.R;
+            int sg = sourceColor.G;
+            int sb = sourceColor.B;
+            int sa = sourceColor.A;
+
+            // TODO: Investigate RGBAW
+            byte r = ((sr * matrix.Matrix00) + (sg * matrix.Matrix10) + (sb * matrix.Matrix20) + (sa * matrix.Matrix30) + (255f * matrix.Matrix40)).ToByte();
+            byte g = ((sr * matrix.Matrix01) + (sg * matrix.Matrix11) + (sb * matrix.Matrix21) + (sa * matrix.Matrix31) + (255f * matrix.Matrix41)).ToByte();
+            byte b = ((sr * matrix.Matrix02) + (sg * matrix.Matrix12) + (sb * matrix.Matrix22) + (sa * matrix.Matrix32) + (255f * matrix.Matrix42)).ToByte();
+            byte a = ((sr * matrix.Matrix03) + (sg * matrix.Matrix13) + (sb * matrix.Matrix23) + (sa * matrix.Matrix33) + (255f * matrix.Matrix43)).ToByte();
+
+            return gamma ? PixelOperations.ToSrgb(new Bgra(b, g, r, a)) : new Bgra(b, g, r, a);
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/GreyscaleBt601.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/GreyscaleBt601.cs
@ -0,0 +1,35 @@
+// <copyright file="GreyscaleBt601.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image to greyscale applying the formula as specified by
+    /// ITU-R Recommendation BT.601 <see href="https://en.wikipedia.org/wiki/Luma_%28video%29#Rec._601_luma_versus_Rec._709_luma_coefficients"/>.
+    /// </summary>
+    public class GreyscaleBt601 : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The inversion matrix.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new float[] { 0.299f, 0.299f, 0.299f, 0, 0 },
+                    new float[] { 0.587f, 0.587f, 0.587f, 0, 0 },
+                    new float[] { 0.114f, 0.114f, 0.114f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new float[] { 0, 0, 0, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GreyscaleBt601"/> class.
+        /// </summary>
+        public GreyscaleBt601()
+            : base(Matrix, true)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/GreyscaleBt709.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/GreyscaleBt709.cs
@ -0,0 +1,35 @@
+// <copyright file="GreyscaleBt709.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image to greyscale applying the formula as specified by
+    /// ITU-R Recommendation BT.709 <see href="https://en.wikipedia.org/wiki/Rec._709#Luma_coefficients"/>.
+    /// </summary>
+    public class GreyscaleBt709 : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The inversion matrix.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new float[] { 0.2126f, 0.2126f, 0.2126f, 0, 0 },
+                    new float[] { 0.7152f, 0.7152f, 0.7152f, 0, 0 },
+                    new float[] { 0.0722f, 0.0722f, 0.0722f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new float[] { 0, 0, 0, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GreyscaleBt709"/> class.
+        /// </summary>
+        public GreyscaleBt709()
+            : base(Matrix, true)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/Invert.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/Invert.cs
@ -0,0 +1,35 @@
+// <copyright file="Invert.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Inverts the colors of the image.
+    /// </summary>
+    public class Invert : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The inversion matrix.
+        /// TODO: With gamma adjustment enabled this leaves the image too bright.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new float[] { -1, 0, 0, 0, 0 },
+                    new float[] { 0, -1, 0, 0, 0 },
+                    new float[] { 0, 0, -1, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new float[] { 1, 1, 1, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Invert"/> class.
+        /// </summary>
+        public Invert()
+            : base(Matrix, false)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/Lomograph.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/Lomograph.cs
@ -0,0 +1,35 @@
+// <copyright file="Lomograph.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image recreating an old Lomograph effect.
+    /// </summary>
+    public class Lomograph : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The Lomograph matrix. Purely artistic in composition.
+        /// TODO: Calculate a matrix that works in the linear color space.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new[] { 1.50f, 0, 0, 0, 0 },
+                    new[] { 0, 1.45f, 0, 0, 0 },
+                    new[] { 0, 0, 1.09f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new[] { -0.10f, 0.05f, -0.08f, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Lomograph"/> class.
+        /// </summary>
+        public Lomograph()
+            : base(Matrix, false)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/Polaroid.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/Polaroid.cs
@ -0,0 +1,35 @@
+// <copyright file="Polaroid.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image recreating an old Polaroid effect.
+    /// </summary>
+    public class Polaroid : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The Polaroid matrix. Purely artistic in composition.
+        /// TODO: Calculate a matrix that works in the linear color space.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new[] { 1.638f, -0.062f, -0.262f, 0, 0 },
+                    new[] { -0.122f, 1.378f, -0.122f, 0, 0 },
+                    new[] { 1.016f, -0.016f, 1.383f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new[] { 0.06f, -0.05f, -0.05f, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Polaroid"/> class.
+        /// </summary>
+        public Polaroid()
+            : base(Matrix, false)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ColorMatrix/Sepia.cs
+++ b/src/ImageProcessor/Filters/ColorMatrix/Sepia.cs
@ -0,0 +1,35 @@
+// <copyright file="Sepia.cs" company="James South">
+// Copyright © James South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    /// <summary>
+    /// Converts the colors of the image to their sepia equivalent recreating an old photo effect.
+    /// </summary>
+    public class Sepia : ColorMatrixFilter
+    {
+        /// <summary>
+        /// The sepia matrix.
+        /// TODO: Calculate a matrix that works in the linear color space.
+        /// </summary>
+        private static readonly ColorMatrix Matrix = new ColorMatrix(
+            new[]
+                {
+                    new[] { .393f, .349f, .272f, 0, 0 },
+                    new[] { .769f, .686f, .534f, 0, 0 },
+                    new[] { .189f, .168f, .131f, 0, 0 },
+                    new float[] { 0, 0, 0, 1, 0 },
+                    new float[] { 0, 0, 0, 0, 1 }
+                });
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Sepia"/> class.
+        /// </summary>
+        public Sepia()
+            : base(Matrix, false)
+        {
+        }
+    }
+}
--- a/src/ImageProcessor/Filters/ImageFilterExtensions.cs
+++ b/src/ImageProcessor/Filters/ImageFilterExtensions.cs
@ -59,5 +59,28 @@ namespace ImageProcessor.Filters
        {
            return source.Process(sourceRectangle, new Alpha(percent));
        }
+
+        /// <summary>
+        /// Alters the alpha component of the image.
+        /// </summary>
+        /// <param name="source">The image this method extends.</param>
+        /// <returns>The <see cref="Image"/>.</returns>
+        public static Image Invert(this Image source)
+        {
+            return Invert(source, source.Bounds);
+        }
+
+        /// <summary>
+        /// Alters the alpha component of the image.
+        /// </summary>
+        /// <param name="source">The image this method extends.</param>
+        /// <param name="sourceRectangle">
+        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to draw.
+        /// </param>
+        /// <returns>The <see cref="Image"/>.</returns>
+        public static Image Invert(this Image source, Rectangle sourceRectangle)
+        {
+            return source.Process(sourceRectangle, new Invert());
+        }
    }
 }
--- a/src/ImageProcessor/Formats/Gif/Quantizer/Quantizer.cs
+++ b/src/ImageProcessor/Formats/Gif/Quantizer/Quantizer.cs
@ -74,7 +74,7 @@ namespace ImageProcessor.Formats
            // Loop through each row
            for (int y = 0; y < height; y++)
            {
-                // And loop through each xumn
+                // And loop through each column
                for (int x = 0; x < width; x++)
                {
                    // Now I have the pixel, call the FirstPassQuantize function...
--- a/src/ImageProcessor/ImageProcessor.csproj
+++ b/src/ImageProcessor/ImageProcessor.csproj
@ -17,6 +17,7 @@
    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
    <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
    <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>cfa9b76b</NuGetPackageImportStamp>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
@ -27,6 +28,7 @@
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <DocumentationFile>bin\Debug\ImageProcessor.XML</DocumentationFile>
+    <LangVersion>default</LangVersion>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <DebugType>pdbonly</DebugType>
@ -44,6 +46,15 @@
    <Compile Include="Common\Helpers\ImageMaths.cs" />
    <Compile Include="Common\Helpers\PixelOperations.cs" />
    <Compile Include="Filters\Alpha.cs" />
+    <Compile Include="Filters\ColorMatrix\ColorMatrix.cs" />
+    <Compile Include="Filters\ColorMatrix\ColorMatrixFilter.cs" />
+    <Compile Include="Filters\ColorMatrix\GreyscaleBt601.cs" />
+    <Compile Include="Filters\ColorMatrix\GreyscaleBt709.cs" />
+    <Compile Include="Filters\ColorMatrix\BlackWhite.cs" />
+    <Compile Include="Filters\ColorMatrix\Polaroid.cs" />
+    <Compile Include="Filters\ColorMatrix\Lomograph.cs" />
+    <Compile Include="Filters\ColorMatrix\Sepia.cs" />
+    <Compile Include="Filters\ColorMatrix\Invert.cs" />
    <Compile Include="Filters\Contrast.cs" />
    <Compile Include="Filters\ImageFilterExtensions.cs" />
    <Compile Include="ImageExtensions.cs" />
@ -210,21 +221,24 @@
    <None Include="Formats\Gif\README.md" />
    <None Include="Formats\Jpg\README.md" />
    <None Include="packages.config" />
+    <None Include="stylecop.json" />
  </ItemGroup>
  <ItemGroup>
    <None Include="Formats\Bmp\README.md" />
    <None Include="Formats\Png\README.md" />
  </ItemGroup>
  <ItemGroup>
-    <Analyzer Include="..\..\packages\StyleCop.Analyzers.1.0.0-beta013\analyzers\dotnet\cs\Newtonsoft.Json.dll" />
-    <Analyzer Include="..\..\packages\StyleCop.Analyzers.1.0.0-beta013\analyzers\dotnet\cs\StyleCop.Analyzers.dll" />
+    <Analyzer Include="..\..\packages\StyleCop.Analyzers.1.0.0-beta015\analyzers\dotnet\cs\Newtonsoft.Json.dll" />
+    <Analyzer Include="..\..\packages\StyleCop.Analyzers.1.0.0-beta015\analyzers\dotnet\cs\StyleCop.Analyzers.dll" />
  </ItemGroup>
  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\Portable\$(TargetFrameworkVersion)\Microsoft.Portable.CSharp.targets" />
  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
    <PropertyGroup>
      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
    </PropertyGroup>
+    <Error Condition="!Exists('..\..\packages\StyleCop.Analyzers.1.0.0-beta015\build\StyleCop.Analyzers.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\StyleCop.Analyzers.1.0.0-beta015\build\StyleCop.Analyzers.targets'))" />
  </Target>
+  <Import Project="..\..\packages\StyleCop.Analyzers.1.0.0-beta015\build\StyleCop.Analyzers.targets" Condition="Exists('..\..\packages\StyleCop.Analyzers.1.0.0-beta015\build\StyleCop.Analyzers.targets')" />
  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
       Other similar extension points exist, see Microsoft.Common.targets.
  <Target Name="BeforeBuild">
--- a/src/ImageProcessor/ImageProcessor.csproj.DotSettings
+++ b/src/ImageProcessor/ImageProcessor.csproj.DotSettings
@ -6,6 +6,7 @@
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=common_005Cextensions/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=common_005Chelpers/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=encoders_005Cgif/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=filters_005Ccolormatrix/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=formats_005Cbmp/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=formats_005Cgif/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=formats_005Cgif_005Cquantizer/@EntryIndexedValue">True</s:Boolean>
--- a/src/ImageProcessor/Settings.StyleCop
+++ b/src/ImageProcessor/Settings.StyleCop
@ -12,6 +12,12 @@
      <Value>scanlines</Value>
      <Value>tEXt</Value>
      <Value>xt</Value>
+      <Value>th</Value>
+      <Value>nd</Value>
+      <Value>rd</Value>
+      <Value>lomograph</Value>
+      <Value>polaroid</Value>
+      <Value>colorspace</Value>
    </CollectionProperty>
  </GlobalSettings>
 </StyleCopSettings>
--- a/src/ImageProcessor/packages.config
+++ b/src/ImageProcessor/packages.config
@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
  <package id="SharpZipLib.Portable" version="0.86.0.0002" targetFramework="portable-net45+win8+wp8" />
-  <package id="StyleCop.Analyzers" version="1.0.0-beta013" targetFramework="portable45-net45+win8+wp8" developmentDependency="true" />
+  <package id="StyleCop.Analyzers" version="1.0.0-beta015" targetFramework="portable-net45+dnxcore50+win+wpa81+wp80" developmentDependency="true" />
 </packages>
--- a/tests/ImageProcessor.Tests/Processors/Filters/FilterTests.cs
+++ b/tests/ImageProcessor.Tests/Processors/Filters/FilterTests.cs
@ -15,6 +15,13 @@ namespace ImageProcessor.Tests
            { "Contrast-50", new Contrast(50) },
            { "Contrast--50", new Contrast(-50) },
            { "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() },
        };

        [Theory]