Fixing halftone output and adding helpers

Disabled tracing in tests.


Former-commit-id: 2d04ae7af4c5ceeb67b8632b1b39cb375b9dec30
Former-commit-id: c51ace483233885b16dd9b69f3f6d397125c80c0

src/ImageProcessor.Playground/Program.cs

@@ -50,23 +50,23 @@ namespace ImageProcessor.PlayGround
 
             // Image mask = Image.FromFile(Path.Combine(resolvedPath, "mask.png"));
             // Image overlay = Image.FromFile(Path.Combine(resolvedPath, "imageprocessor.128.png"));
-            FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "ej.jpg"));
+            //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "2008.jpg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "new-york.jpg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "mountain.jpg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "Arc-de-Triomphe-France.jpg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "Martin-Schoeller-Jack-Nicholson-Portrait.jpeg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "crop-base-300x200.jpg"));
             //FileInfo fileInfo = new FileInfo(Path.Combine(resolvedPath, "cmyk.png"));
-            //IEnumerable<FileInfo> files = GetFilesByExtensions(di, ".jpg", ".jpeg", ".jfif");
-
+            //IEnumerable<FileInfo> files = GetFilesByExtensions(di, ".gif");
+            IEnumerable<FileInfo> files = GetFilesByExtensions(di, ".jpg", ".jpeg", ".jfif");
             //IEnumerable<FileInfo> files = GetFilesByExtensions(di, ".gif", ".webp", ".bmp", ".jpg", ".png", ".tif");
 
-            //foreach (FileInfo fileInfo in files)
-            //{
-                //if (fileInfo.Name == "test5.jpg")
-                //{
-                //    continue;
-                //}
+            foreach (FileInfo fileInfo in files)
+            {
+                if (fileInfo.Name == "test5.jpg")
+                {
+                    continue;
+                }
 
                 byte[] photoBytes = File.ReadAllBytes(fileInfo.FullName);
                 Console.WriteLine("Processing: " + fileInfo.Name);
@@ -79,8 +79,8 @@ namespace ImageProcessor.PlayGround
                 {
                     using (ImageFactory imageFactory = new ImageFactory(true))
                     {
-                        Size size = new Size(844, 1017);
-                        ResizeLayer layer = new ResizeLayer(size, ResizeMode.Max, AnchorPosition.Center, false);
+                        Size size = new Size(1024, 0);
+                        //ResizeLayer layer = new ResizeLayer(size, ResizeMode.Max, AnchorPosition.Center, false);
 
                         //ContentAwareResizeLayer layer = new ContentAwareResizeLayer(size)
                         //{
@@ -102,7 +102,7 @@ namespace ImageProcessor.PlayGround
                             //.Format(new PngFormat())
                             //.BackgroundColor(Color.Cyan)
                             //.ReplaceColor(Color.FromArgb(255, 223, 224), Color.FromArgb(121, 188, 255), 128)
-                            //.Resize(size)
+                            .Resize(size)
                             //.Resize(new ResizeLayer(size, ResizeMode.Max))
                             // .Resize(new ResizeLayer(size, ResizeMode.Stretch))
                             //.DetectEdges(new Laplacian3X3EdgeFilter(), true)
@@ -119,8 +119,8 @@ namespace ImageProcessor.PlayGround
                             //.GaussianSharpen(10)
                             //.Format(new PngFormat() { IsIndexed = true })
                             //.Format(new PngFormat() { IsIndexed = true })
-                            //.Save(Path.GetFullPath(Path.Combine(Path.GetDirectoryName(path), @"..\..\images\output", fileInfo.Name)));
-                            .Save(Path.GetFullPath(Path.Combine(Path.GetDirectoryName(path), @"..\..\images\output", Path.GetFileNameWithoutExtension(fileInfo.Name) + ".png")));
+                            .Save(Path.GetFullPath(Path.Combine(Path.GetDirectoryName(path), @"..\..\images\output", fileInfo.Name)));
+                        //.Save(Path.GetFullPath(Path.Combine(Path.GetDirectoryName(path), @"..\..\images\output", Path.GetFileNameWithoutExtension(fileInfo.Name) + ".png")));
 
                         stopwatch.Stop();
                     }
@@ -132,7 +132,7 @@ namespace ImageProcessor.PlayGround
                 Console.WriteLine(@"Completed {0} in {1:s\.fff} secs {2}Peak memory usage was {3} bytes or {4} Mb.", fileInfo.Name, stopwatch.Elapsed, Environment.NewLine, peakWorkingSet64.ToString("#,#"), mB);
 
                 //Console.WriteLine("Processed: " + fileInfo.Name + " in " + stopwatch.ElapsedMilliseconds + "ms");
-            //}
+            }
 
             Console.ReadLine();
         }

src/ImageProcessor/Common/Extensions/DoubleExtensions.cs

@@ -12,6 +12,8 @@ namespace ImageProcessor.Common.Extensions
 {
     using System;
 
+    using ImageProcessor.Imaging.Helpers;
+
     /// <summary>
     /// Encapsulates a series of time saving extension methods to the <see cref="T:System.Double"/> class.
     /// </summary>
@@ -24,15 +26,15 @@ namespace ImageProcessor.Common.Extensions
         /// those restricted ranges.
         /// </remarks>
         /// </summary>
-        /// <param name="d">
+        /// <param name="value">
         /// The <see cref="T:System.Double"/> to convert.
         /// </param>
         /// <returns>
         /// The <see cref="T:System.Byte"/>.
         /// </returns>
-        public static byte ToByte(this double d)
+        public static byte ToByte(this double value)
         {
-            return Convert.ToByte(Math.Max(0.0d, Math.Min(255d, d))); 
+            return Convert.ToByte(ImageMaths.Clamp(value, 0, 255));
         }
     }
 }

src/ImageProcessor/Common/Extensions/IntegerExtensions.cs

@@ -10,8 +10,11 @@
 
 namespace ImageProcessor.Common.Extensions
 {
+    using System;
     using System.Globalization;
 
+    using ImageProcessor.Imaging.Helpers;
+
     /// <summary>
     /// Encapsulates a series of time saving extension methods to the <see cref="T:System.Int32"/> class.
     /// </summary>
@@ -24,27 +27,27 @@ namespace ImageProcessor.Common.Extensions
         /// those restricted ranges.
         /// </remarks>
         /// </summary>
-        /// <param name="integer">
+        /// <param name="value">
         /// The <see cref="T:System.Int32"/> to convert.
         /// </param>
         /// <returns>
         /// The <see cref="T:System.Byte"/>.
         /// </returns>
-        public static byte ToByte(this int integer)
+        public static byte ToByte(this int value)
         {
-            return ((double)integer).ToByte();
+            return Convert.ToByte(ImageMaths.Clamp(value, 0, 255));
         }
 
         /// <summary>
         /// Converts the string representation of a number in a specified culture-specific format to its 
         /// 32-bit signed integer equivalent using invariant culture.
         /// </summary>
-        /// <param name="integer">The integer.</param>
-        /// <param name="s">A string containing a number to convert.</param>
-        /// <returns>A 32-bit signed integer equivalent to the number specified in s.</returns>
-        public static int ParseInvariant(this int integer, string s)
+        /// <param name="value">The integer.</param>
+        /// <param name="toParse">A string containing a number to convert.</param>
+        /// <returns>A 32-bit signed integer equivalent to the number specified in toParse.</returns>
+        public static int ParseInvariant(this int value, string toParse)
         {
-            return int.Parse(s, CultureInfo.InvariantCulture);
+            return int.Parse(toParse, CultureInfo.InvariantCulture);
         }
     }
 }

src/ImageProcessor/Imaging/Colors/CmykColor.cs

@@ -14,6 +14,7 @@ namespace ImageProcessor.Imaging.Colors
     using System.Drawing;
 
     using ImageProcessor.Common.Extensions;
+    using ImageProcessor.Imaging.Helpers;
 
     /// <summary>
     /// Represents an CMYK (cyan, magenta, yellow, keyline) color.
@@ -355,16 +356,7 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         private static float Clamp(float value)
         {
-            if (value < 0.0)
-            {
-                value = 0.0f;
-            }
-            else if (value > 100)
-            {
-                value = 100f;
-            }
-
-            return value;
+            return ImageMaths.Clamp(value, 0, 100);
         }
 
         /// <summary>

src/ImageProcessor/Imaging/Colors/ColorExtensions.cs

@@ -1,17 +1,37 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="ColorExtensions.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// <summary>
+//   Provides extensions for manipulating colors.
+// </summary>
+// --------------------------------------------------------------------------------------------------------------------
 
 namespace ImageProcessor.Imaging.Colors
 {
+    using System;
     using System.Drawing;
 
     using ImageProcessor.Common.Extensions;
 
+    /// <summary>
+    /// Provides extensions for manipulating colors.
+    /// </summary>
     internal static class ColorExtensions
     {
+        /// <summary>
+        /// Adds colors together using the RGBA color format.
+        /// </summary>
+        /// <param name="color">
+        /// The color to add to.
+        /// </param>
+        /// <param name="colors">
+        /// The colors to add to the initial one.
+        /// </param>
+        /// <returns>
+        /// The combined <see cref="Color"/>.
+        /// </returns>
         public static Color Add(this Color color, params Color[] colors)
         {
             int red = color.A > 0 ? color.R : 0;
@@ -37,6 +57,18 @@ namespace ImageProcessor.Imaging.Colors
             return Color.FromArgb((alpha / counter).ToByte(), (red / counter).ToByte(), (green / counter).ToByte(), (blue / counter).ToByte());
         }
 
+        /// <summary>
+        /// Adds colors together using the CMYK color format.
+        /// </summary>
+        /// <param name="color">
+        /// The color to add to.
+        /// </param>
+        /// <param name="colors">
+        /// The colors to add to the initial one.
+        /// </param>
+        /// <returns>
+        /// The combined <see cref="CmykColor"/>.
+        /// </returns>
         public static CmykColor AddAsCmykColor(this Color color, params Color[] colors)
         {
             CmykColor cmyk = color;
@@ -57,11 +89,6 @@ namespace ImageProcessor.Imaging.Colors
                 }
             }
 
-            //c = Math.Max(0.0f, Math.Min(100f, c));
-            //m = Math.Max(0.0f, Math.Min(100f, m));
-            //y = Math.Max(0.0f, Math.Min(100f, y));
-            //k = Math.Max(0.0f, Math.Min(100f, k));
-
             return CmykColor.FromCmykColor(c, m, y, k);
         }
     }

src/ImageProcessor/Imaging/Colors/HSLAColor.cs

@@ -10,6 +10,8 @@ namespace ImageProcessor.Imaging.Colors
     using System;
     using System.Drawing;
 
+    using ImageProcessor.Imaging.Helpers;
+
     /// <summary>
     /// Represents an HSLA (hue, saturation, luminosity, alpha) color.
     /// Adapted from <see href="http://richnewman.wordpress.com/about/code-listings-and-diagrams/hslcolor-class/"/>
@@ -493,16 +495,7 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         private static float Clamp(float value)
         {
-            if (value < 0.0)
-            {
-                value = 0.0f;
-            }
-            else if (value > 1.0)
-            {
-                value = 1.0f;
-            }
-
-            return value;
+            return ImageMaths.Clamp(value, 0, 1);
         }
 
         /// <summary>

src/ImageProcessor/Imaging/Colors/YCbCrColor.cs

@@ -14,6 +14,8 @@ namespace ImageProcessor.Imaging.Colors
     using System;
     using System.Drawing;
 
+    using ImageProcessor.Imaging.Helpers;
+
     /// <summary>
     /// Represents an YCbCr (luminance, chroma, chroma) color conforming to the ITU-R BT.601 standard used in digital imaging systems.
     /// <see href="http://en.wikipedia.org/wiki/YCbCr"/>
@@ -48,9 +50,9 @@ namespace ImageProcessor.Imaging.Colors
         /// <param name="cr">The v chroma component.</param> 
         private YCbCrColor(float y, float cb, float cr)
         {
-            this.y = Math.Max(0f, Math.Min(255f, y));
-            this.cb = Math.Max(-255f, Math.Min(255f, cb));
-            this.cr = Math.Max(-255f, Math.Min(255f, cr));
+            this.y = ImageMaths.Clamp(y, 0, 255);
+            this.cb = ImageMaths.Clamp(cb, -255, 255);
+            this.cr = ImageMaths.Clamp(cr, -255, 255);
         }
 
         /// <summary>

src/ImageProcessor/Imaging/Filters/Artistic/HalftoneFilter.cs

@@ -12,6 +12,7 @@ namespace ImageProcessor.Imaging.Filters.Artistic
 {
     using System;
     using System.Drawing;
+    using System.Drawing.Drawing2D;
     using System.Threading.Tasks;
 
     using ImageProcessor.Imaging.Colors;
@@ -167,9 +168,14 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                 int width = source.Width;
                 int height = source.Height;
 
+                int minHeight = -height * 2;
+                int maxHeight = height * 2;
+                int minWidth = -width * 2;
+                int maxWidth = width * 2;
+
                 float multiplier = 4 * (float)Math.Sqrt(2);
-                float max = this.distance + (float)Math.Sqrt(2);
-                float keylineMax = max + 1;
+                float max = this.distance + ((float)Math.Sqrt(2) / 2);
+                float keylineMax = this.distance + (float)Math.Sqrt(2) + ((float)Math.Sqrt(2) / 2);
 
                 // Cyan color sampled from Wikipedia page. Keyline brush is declared
                 // separately.
@@ -199,19 +205,27 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                 using (Graphics graphicsYellow = Graphics.FromImage(yellow))
                 using (Graphics graphicsKeyline = Graphics.FromImage(keyline))
                 {
-                    // Ensure cleared out.
+                    // Set the quality properties.
+                    graphicsCyan.PixelOffsetMode = PixelOffsetMode.HighQuality;
+                    graphicsMagenta.PixelOffsetMode = PixelOffsetMode.HighQuality;
+                    graphicsYellow.PixelOffsetMode = PixelOffsetMode.HighQuality;
+                    graphicsKeyline.PixelOffsetMode = PixelOffsetMode.HighQuality;
+
+                    // Set up the canvas.
                     graphicsCyan.Clear(Color.Transparent);
                     graphicsMagenta.Clear(Color.Transparent);
                     graphicsYellow.Clear(Color.Transparent);
                     graphicsKeyline.Clear(Color.Transparent);
 
+                    int d = this.distance;
+
                     // This is too slow. The graphics object can't be called within a parallel 
                     // loop so we have to do it old school. :(
                     using (FastBitmap sourceBitmap = new FastBitmap(source))
                     {
-                        for (int y = -height * 2; y < height * 2; y += this.distance)
+                        for (int y = minHeight; y < maxHeight; y += d)
                         {
-                            for (int x = -width * 2; x < width * 2; x += this.distance)
+                            for (int x = minWidth; x < maxWidth; x += d)
                             {
                                 Color color;
                                 CmykColor cmykColor;
@@ -225,7 +239,7 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                                 {
                                     color = sourceBitmap.GetPixel(angledX, angledY);
                                     cmykColor = color;
-                                    brushWidth = Math.Max(0, Math.Min(max, this.distance * (cmykColor.C / 255f) * multiplier));
+                                    brushWidth = ImageMaths.Clamp(d * (cmykColor.C / 255f) * multiplier, 0, max);
                                     graphicsCyan.FillEllipse(cyanBrush, angledX, angledY, brushWidth, brushWidth);
                                 }
 
@@ -237,7 +251,7 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                                 {
                                     color = sourceBitmap.GetPixel(angledX, angledY);
                                     cmykColor = color;
-                                    brushWidth = Math.Max(0, Math.Min(max, this.distance * (cmykColor.M / 255f) * multiplier));
+                                    brushWidth = ImageMaths.Clamp(d * (cmykColor.M / 255f) * multiplier, 0, max);
                                     graphicsMagenta.FillEllipse(magentaBrush, angledX, angledY, brushWidth, brushWidth);
                                 }
 
@@ -249,7 +263,7 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                                 {
                                     color = sourceBitmap.GetPixel(angledX, angledY);
                                     cmykColor = color;
-                                    brushWidth = Math.Max(0, Math.Min(max, this.distance * (cmykColor.Y / 255f) * multiplier));
+                                    brushWidth = ImageMaths.Clamp(d * (cmykColor.Y / 255f) * multiplier, 0, max);
                                     graphicsYellow.FillEllipse(yellowBrush, angledX, angledY, brushWidth, brushWidth);
                                 }
 
@@ -261,7 +275,7 @@ namespace ImageProcessor.Imaging.Filters.Artistic
                                 {
                                     color = sourceBitmap.GetPixel(angledX, angledY);
                                     cmykColor = color;
-                                    brushWidth = Math.Max(0, Math.Min(keylineMax, this.distance * (cmykColor.K / 255f) * multiplier));
+                                    brushWidth = ImageMaths.Clamp(d * (cmykColor.K / 255f) * multiplier, 0, keylineMax);
 
                                     // Just using black is too dark. 
                                     Brush keylineBrush = new SolidBrush(CmykColor.FromCmykColor(0, 0, 0, cmykColor.K));
@@ -342,5 +356,17 @@ namespace ImageProcessor.Imaging.Filters.Artistic
 
             return source;
         }
+
+        private void SetGraphicsSettings(ref Graphics graphics)
+        {
+            // Set the quality properties.
+            graphics.SmoothingMode = graphics.SmoothingMode = SmoothingMode.AntiAlias;
+            graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
+            graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
+            graphics.CompositingQuality = CompositingQuality.HighQuality;
+
+            // Set up the canvas.
+            graphics.Clear(Color.Transparent);
+        }
     }
 }

src/ImageProcessor/Imaging/Helpers/ImageMaths.cs

@@ -20,6 +20,39 @@ namespace ImageProcessor.Imaging.Helpers
     /// </summary>
     public static class ImageMaths
     {
+        /// <summary>
+        /// Restricts a value to be within a specified range.
+        /// </summary>
+        /// <param name="value">
+        /// The The value to clamp.
+        /// </param>
+        /// <param name="min">
+        /// The minimum value. If value is less than min, min will be returned.
+        /// </param>
+        /// <param name="max">
+        /// The maximum value. If value is greater than max, max will be returned.
+        /// </param>
+        /// <typeparam name="T">
+        /// The <see cref="System.Type"/> to clamp.
+        /// </typeparam>
+        /// <returns>
+        /// The <see cref="T"/> representing the clamped value.
+        /// </returns>
+        public static T Clamp<T>(T value, T min, T max) where T : IComparable<T>
+        {
+            if (value.CompareTo(min) < 0)
+            {
+                return min;
+            }
+
+            if (value.CompareTo(max) > 0)
+            {
+                return max;
+            }
+
+            return value;
+        }
+
         /// <summary>
         /// Gets the bounding <see cref="Rectangle"/> from the given points.
         /// </summary>

src/ImageProcessor/Processors/Halftone.cs

@@ -70,7 +70,7 @@ namespace ImageProcessor.Processors
             int width = image.Width;
             int height = image.Height;
             Bitmap newImage = null;
-            Bitmap edgeBitmap = null;
+            //Bitmap edgeBitmap = null;
             try
             {
                 HalftoneFilter filter = new HalftoneFilter(5);
@@ -79,34 +79,34 @@ namespace ImageProcessor.Processors
                 newImage = filter.ApplyFilter(newImage);
 
                 // Draw the edges.
-                edgeBitmap = new Bitmap(width, height);
-                edgeBitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution);
-                edgeBitmap = Trace(image, edgeBitmap, 120);
+                //edgeBitmap = new Bitmap(width, height);
+                //edgeBitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution);
+                //edgeBitmap = Trace(image, edgeBitmap, 120);
 
                 using (Graphics graphics = Graphics.FromImage(newImage))
                 {
                     // Overlay the image.
-                    graphics.DrawImage(edgeBitmap, 0, 0);
+                    //graphics.DrawImage(edgeBitmap, 0, 0);
                     Rectangle rectangle = new Rectangle(0, 0, width, height);
 
                     // Draw an edge around the image.
-                    using (Pen blackPen = new Pen(Color.Black))
-                    {
-                        blackPen.Width = 4;
-                        graphics.DrawRectangle(blackPen, rectangle);
-                    }
+                    //using (Pen blackPen = new Pen(Color.Black))
+                    //{
+                    //    blackPen.Width = 4;
+                    //    graphics.DrawRectangle(blackPen, rectangle);
+                    //}
                 }
 
-                edgeBitmap.Dispose();
+                //edgeBitmap.Dispose();
                 image.Dispose();
                 image = newImage;
             }
             catch (Exception ex)
             {
-                if (edgeBitmap != null)
-                {
-                    edgeBitmap.Dispose();
-                }
+                //if (edgeBitmap != null)
+                //{
+                //    edgeBitmap.Dispose();
+                //}
 
                 if (newImage != null)
                 {