Adding brightness and contrast

Former-commit-id: cae63b45e203c8581d183d55a74101697e391acd

src/ImageProcessor/Helpers/Extensions/StringExtensions.cs

@@ -118,7 +118,7 @@ namespace ImageProcessor.Helpers.Extensions
         {
             Contract.Requires(!string.IsNullOrWhiteSpace(expression));
 
-            Regex regex = new Regex(@"\d+", RegexOptions.Compiled);
+            Regex regex = new Regex(@"(-|)\d+", RegexOptions.Compiled);
 
             MatchCollection matchCollection = regex.Matches(expression);
 

src/ImageProcessor/ImageFactory.cs

@@ -196,7 +196,10 @@ namespace ImageProcessor
         /// <summary>
         /// Changes the opacity of the current image.
         /// </summary>
-        /// <param name="percentage">The percentage by which to alter the images opacity.</param>
+        /// <param name="percentage">
+        /// The percentage by which to alter the images opacity.
+        /// Any integer between 0 and 100.
+        /// </param>
         /// <returns>
         /// The current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
         /// </returns>
@@ -204,6 +207,12 @@ namespace ImageProcessor
         {
             if (this.ShouldProcess)
             {
+                // Sanitize the input.
+                if (percentage > 100 || percentage < 0)
+                {
+                    percentage = 0;
+                }
+
                 Alpha alpha = new Alpha { DynamicParameter = percentage };
 
                 this.Image = alpha.ProcessImage(this);
@@ -212,6 +221,62 @@ namespace ImageProcessor
             return this;
         }
 
+        /// <summary>
+        /// Changes the brightness of the current image.
+        /// </summary>
+        /// <param name="percentage">
+        /// The percentage by which to alter the images brightness.
+        /// Any integer between -100 and 100.
+        /// </param>
+        /// <returns>
+        /// The current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
+        /// </returns>
+        public ImageFactory Brightness(int percentage)
+        {
+            if (this.ShouldProcess)
+            {
+                // Sanitize the input.
+                if (percentage > 100 || percentage < -100)
+                {
+                    percentage = 0;
+                }
+
+                Brightness brightness = new Brightness { DynamicParameter = percentage };
+
+                this.Image = brightness.ProcessImage(this);
+            }
+
+            return this;
+        }
+
+        /// <summary>
+        /// Changes the contrast of the current image.
+        /// </summary>
+        /// <param name="percentage">
+        /// The percentage by which to alter the images contrast.
+        /// Any integer between -100 and 100.
+        /// </param>
+        /// <returns>
+        /// The current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
+        /// </returns>
+        public ImageFactory Contrast(int percentage)
+        {
+            if (this.ShouldProcess)
+            {
+                // Sanitize the input.
+                if (percentage > 100 || percentage < -100)
+                {
+                    percentage = 0;
+                }
+
+                Contrast contrast = new Contrast { DynamicParameter = percentage };
+
+                this.Image = contrast.ProcessImage(this);
+            }
+
+            return this;
+        }
+
         /// <summary>
         /// Crops an image to the given coordinates.
         /// </summary>

src/ImageProcessor/ImageProcessor.csproj

@@ -110,6 +110,8 @@
     <Compile Include="Imaging\RotateLayer.cs" />
     <Compile Include="Imaging\TextLayer.cs" />
     <Compile Include="Processors\Alpha.cs" />
+    <Compile Include="Processors\Brightness.cs" />
+    <Compile Include="Processors\Contrast.cs" />
     <Compile Include="Processors\Flip.cs" />
     <Compile Include="Processors\Rotate.cs" />
     <Compile Include="Processors\Crop.cs" />

src/ImageProcessor/Processors/Brightness.cs

@@ -0,0 +1,185 @@
+// -----------------------------------------------------------------------
+// <copyright file="Brightness.cs" company="James South">
+//     Copyright (c) James South.
+//     Licensed under the Apache License, Version 2.0.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace ImageProcessor.Processors
+{
+    #region Using
+    using System.Collections.Generic;
+    using System.Drawing;
+    using System.Drawing.Imaging;
+    using System.Text.RegularExpressions;
+    using ImageProcessor.Helpers.Extensions;
+    #endregion
+
+    /// <summary>
+    /// Encapsulates methods to change the brightness component of the image.
+    /// </summary>
+    public class Brightness : IGraphicsProcessor
+    {
+        /// <summary>
+        /// The regular expression to search strings for.
+        /// <see cref="http://stackoverflow.com/a/6400969/427899"/> 
+        /// </summary>
+        private static readonly Regex QueryRegex = new Regex(@"brightness=(-|)(?:100|[1-9]?[0-9])", RegexOptions.Compiled);
+
+        #region IGraphicsProcessor Members
+        /// <summary>
+        /// Gets the name.
+        /// </summary>
+        public string Name
+        {
+            get
+            {
+                return "Brightness";
+            }
+        }
+
+        /// <summary>
+        /// Gets the description.
+        /// </summary>
+        public string Description
+        {
+            get
+            {
+                return "Changes the the brightness component of the image.";
+            }
+        }
+
+        /// <summary>
+        /// Gets the regular expression to search strings for.
+        /// </summary>
+        public Regex RegexPattern
+        {
+            get
+            {
+                return QueryRegex;
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets DynamicParameter.
+        /// </summary>
+        public dynamic DynamicParameter
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// Gets the order in which this processor is to be used in a chain.
+        /// </summary>
+        public int SortOrder
+        {
+            get;
+            private set;
+        }
+
+        /// <summary>
+        /// Gets or sets any additional settings required by the processor.
+        /// </summary>
+        public Dictionary<string, string> Settings
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// The position in the original string where the first character of the captured substring was found.
+        /// </summary>
+        /// <param name="queryString">
+        /// The query string to search.
+        /// </param>
+        /// <returns>
+        /// The zero-based starting position in the original string where the captured substring was found.
+        /// </returns>
+        public int MatchRegexIndex(string queryString)
+        {
+            int index = 0;
+
+            // Set the sort order to max to allow filtering.
+            this.SortOrder = int.MaxValue;
+
+            foreach (Match match in this.RegexPattern.Matches(queryString))
+            {
+                if (match.Success)
+                {
+                    if (index == 0)
+                    {
+                        // Set the index on the first instance only.
+                        this.SortOrder = match.Index;
+                        int percentage = match.Value.ToIntegerArray()[0];
+
+                        this.DynamicParameter = percentage;
+                    }
+
+                    index += 1;
+                }
+            }
+
+            return this.SortOrder;
+        }
+
+        /// <summary>
+        /// Processes the image.
+        /// </summary>
+        /// <param name="factory">
+        /// The the current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class containing
+        /// the image to process.
+        /// </param>
+        /// <returns>
+        /// The processed image from the current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
+        /// </returns>
+        public Image ProcessImage(ImageFactory factory)
+        {
+            Bitmap newImage = null;
+            Image image = factory.Image;
+
+            try
+            {
+                float brightnessFactor = (float)this.DynamicParameter / 100;
+
+                // Dont use an object initializer here.
+                newImage = new Bitmap(image.Width, image.Height, PixelFormat.Format32bppPArgb);
+                newImage.Tag = image.Tag;
+
+                ColorMatrix colorMatrix = new ColorMatrix(
+                                                new float[][]
+                                                        {
+                                                            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[] { brightnessFactor, brightnessFactor, brightnessFactor, 0, 1 }
+                                                      });
+
+
+                using (Graphics graphics = Graphics.FromImage(newImage))
+                {
+                    using (ImageAttributes imageAttributes = new ImageAttributes())
+                    {
+                        imageAttributes.SetColorMatrix(colorMatrix);
+
+                        graphics.DrawImage(image, new Rectangle(0, 0, image.Width, image.Height), 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, imageAttributes);
+
+                        image.Dispose();
+                        image = newImage;
+                    }
+                }
+            }
+            catch
+            {
+                if (newImage != null)
+                {
+                    newImage.Dispose();
+                }
+            }
+
+            return image;
+        }
+        #endregion
+    }
+}

src/ImageProcessor/Processors/Contrast.cs

@@ -0,0 +1,188 @@
+// -----------------------------------------------------------------------
+// <copyright file="Contrast.cs" company="James South">
+//     Copyright (c) James South.
+//     Licensed under the Apache License, Version 2.0.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace ImageProcessor.Processors
+{
+    #region Using
+    using System.Collections.Generic;
+    using System.Drawing;
+    using System.Drawing.Imaging;
+    using System.Text.RegularExpressions;
+    using ImageProcessor.Helpers.Extensions;
+    #endregion
+
+    /// <summary>
+    /// Encapsulates methods to change the contrast component of the image.
+    /// </summary>
+    public class Contrast : IGraphicsProcessor
+    {
+        /// <summary>
+        /// The regular expression to search strings for.
+        /// <see cref="http://stackoverflow.com/a/6400969/427899"/> 
+        /// </summary>
+        private static readonly Regex QueryRegex = new Regex(@"contrast=(-|)(?:100|[1-9]?[0-9])", RegexOptions.Compiled);
+
+        #region IGraphicsProcessor Members
+        /// <summary>
+        /// Gets the name.
+        /// </summary>
+        public string Name
+        {
+            get
+            {
+                return "Contrast";
+            }
+        }
+
+        /// <summary>
+        /// Gets the description.
+        /// </summary>
+        public string Description
+        {
+            get
+            {
+                return "Changes the the contrast component of the image.";
+            }
+        }
+
+        /// <summary>
+        /// Gets the regular expression to search strings for.
+        /// </summary>
+        public Regex RegexPattern
+        {
+            get
+            {
+                return QueryRegex;
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets DynamicParameter.
+        /// </summary>
+        public dynamic DynamicParameter
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// Gets the order in which this processor is to be used in a chain.
+        /// </summary>
+        public int SortOrder
+        {
+            get;
+            private set;
+        }
+
+        /// <summary>
+        /// Gets or sets any additional settings required by the processor.
+        /// </summary>
+        public Dictionary<string, string> Settings
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// The position in the original string where the first character of the captured substring was found.
+        /// </summary>
+        /// <param name="queryString">
+        /// The query string to search.
+        /// </param>
+        /// <returns>
+        /// The zero-based starting position in the original string where the captured substring was found.
+        /// </returns>
+        public int MatchRegexIndex(string queryString)
+        {
+            int index = 0;
+
+            // Set the sort order to max to allow filtering.
+            this.SortOrder = int.MaxValue;
+
+            foreach (Match match in this.RegexPattern.Matches(queryString))
+            {
+                if (match.Success)
+                {
+                    if (index == 0)
+                    {
+                        // Set the index on the first instance only.
+                        this.SortOrder = match.Index;
+                        int percentage = match.Value.ToIntegerArray()[0];
+
+                        this.DynamicParameter = percentage;
+                    }
+
+                    index += 1;
+                }
+            }
+
+            return this.SortOrder;
+        }
+
+        /// <summary>
+        /// Processes the image.
+        /// </summary>
+        /// <param name="factory">
+        /// The the current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class containing
+        /// the image to process.
+        /// </param>
+        /// <returns>
+        /// The processed image from the current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
+        /// </returns>
+        public Image ProcessImage(ImageFactory factory)
+        {
+            Bitmap newImage = null;
+            Image image = factory.Image;
+
+            try
+            {
+                float contrastFactor = (float)this.DynamicParameter / 100;
+
+                // Stop at -1 to prevent inversion.
+                contrastFactor++;
+                float factorTransform = 0.5f * (1.0f - contrastFactor);
+
+                // Dont use an object initializer here.
+                newImage = new Bitmap(image.Width, image.Height, PixelFormat.Format32bppPArgb);
+                newImage.Tag = image.Tag;
+
+                ColorMatrix colorMatrix = new ColorMatrix(
+                                                new float[][]
+                                                        {
+                                                            new float[] { contrastFactor, 0, 0, 0, 0 }, 
+                                                            new float[] { 0, contrastFactor, 0, 0, 0 },
+                                                            new float[] { 0, 0, contrastFactor, 0, 0 },
+                                                            new float[] { 0, 0, 0, 1, 0 },
+                                                            new float[] { factorTransform, factorTransform, factorTransform, 0, 1 }
+                                                      });
+
+                using (Graphics graphics = Graphics.FromImage(newImage))
+                {
+                    using (ImageAttributes imageAttributes = new ImageAttributes())
+                    {
+                        imageAttributes.SetColorMatrix(colorMatrix);
+
+                        graphics.DrawImage(image, new Rectangle(0, 0, image.Width, image.Height), 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, imageAttributes);
+
+                        image.Dispose();
+                        image = newImage;
+                    }
+                }
+            }
+            catch
+            {
+                if (newImage != null)
+                {
+                    newImage.Dispose();
+                }
+            }
+
+            return image;
+        }
+        #endregion
+    }
+}