Fixing YcbCr

Former-commit-id: 940697fd8a7d4889a263209975a1043d5e24f125

src/ImageProcessor.UnitTests/Imaging/ColorUnitTests.cs

@@ -25,7 +25,7 @@ namespace ImageProcessor.UnitTests.Imaging
         /// Tests the <see cref="RgbaColor"/> struct equality operators.
         /// </summary>
         [Test]
-        public void TestRGBAEquality()
+        public void TestRgbaEquality()
         {
             RgbaColor first = RgbaColor.FromColor(Color.White);
             RgbaColor second = RgbaColor.FromColor(Color.White);
@@ -34,10 +34,10 @@ namespace ImageProcessor.UnitTests.Imaging
         }
 
         /// <summary>
-        /// Tests the <see cref="RgbaColor"/> struct equality operators.
+        /// Tests the <see cref="HslaColor"/> struct equality operators.
         /// </summary>
         [Test]
-        public void TestHSLAEquality()
+        public void TestHslaEquality()
         {
             HslaColor first = HslaColor.FromColor(Color.White);
             HslaColor second = HslaColor.FromColor(Color.White);
@@ -45,6 +45,18 @@ namespace ImageProcessor.UnitTests.Imaging
             Assert.AreEqual(first, second);
         }
 
+        /// <summary>
+        /// Tests the <see cref="YCbCrColor"/> struct equality operators.
+        /// </summary>
+        [Test]
+        public void TestYCbCrEquality()
+        {
+            YCbCrColor first = YCbCrColor.FromColor(Color.White);
+            YCbCrColor second = YCbCrColor.FromColor(Color.White);
+
+            Assert.AreEqual(first, second);
+        }
+
         /// <summary>
         /// Test conversion to and from a <see cref="HslaColor"/>.
         /// </summary>
@@ -52,9 +64,13 @@ namespace ImageProcessor.UnitTests.Imaging
         /// The expected output.
         /// </param>
         [Test]
+        [TestCase("#FFFFFF")]
         [TestCase("#FEFFFE")]
+        [TestCase("#F0F8FF")]
         [TestCase("#000000")]
         [TestCase("#CCFF33")]
+        [TestCase("#00FF00")]
+        [TestCase("#FF00FF")]
         [TestCase("#990000")]
         [TestCase("#5C955C")]
         [TestCase("#5C5C95")]
@@ -77,9 +93,13 @@ namespace ImageProcessor.UnitTests.Imaging
         /// The expected output.
         /// </param>
         [Test]
+        [TestCase("#FFFFFF")]
         [TestCase("#FEFFFE")]
+        [TestCase("#F0F8FF")]
         [TestCase("#000000")]
         [TestCase("#CCFF33")]
+        [TestCase("#00FF00")]
+        [TestCase("#FF00FF")]
         [TestCase("#990000")]
         [TestCase("#5C955C")]
         [TestCase("#5C5C95")]
@@ -95,29 +115,33 @@ namespace ImageProcessor.UnitTests.Imaging
             Assert.AreEqual(expected, result);
         }
 
-        ///// <summary>
+        /// <summary>
-        ///// Test conversion to and from a <see cref="RgbaColor"/>.
+        /// Test conversion to and from a <see cref="RgbaColor"/>.
-        ///// </summary>
+        /// </summary>
-        ///// <param name="expected">
+        /// <param name="expected">
-        ///// The expected output.
+        /// The expected output.
-        ///// </param>
+        /// </param>
-        //[SuppressMessage("StyleCop.CSharp.NamingRules", "SA1305:FieldNamesMustNotUseHungarianNotation", Justification = "Reviewed. Suppression is OK here."),Test]
+        [SuppressMessage("StyleCop.CSharp.NamingRules", "SA1305:FieldNamesMustNotUseHungarianNotation", Justification = "Reviewed. Suppression is OK here."), Test]
-        //[TestCase("#FEFFFE")]
+        [TestCase("#FFFFFF")]
-        //[TestCase("#000000")]
+        [TestCase("#FEFFFE")]
-        //[TestCase("#CCFF33")]
+        [TestCase("#F0F8FF")]
-        //[TestCase("#990000")]
+        [TestCase("#000000")]
-        //[TestCase("#5C955C")]
+        [TestCase("#CCFF33")]
-        //[TestCase("#5C5C95")]
+        [TestCase("#00FF00")]
-        //[TestCase("#3F3F66")]
+        [TestCase("#FF00FF")]
-        //[TestCase("#FFFFBB")]
+        [TestCase("#990000")]
-        //[TestCase("#FF002B")]
+        [TestCase("#5C955C")]
-        //[TestCase("#00ABFF")]
+        [TestCase("#5C5C95")]
-        //public void TestYCbCrConversion(string expected)
+        [TestCase("#3F3F66")]
-        //{
+        [TestCase("#FFFFBB")]
-        //    Color color = ColorTranslator.FromHtml(expected);
+        [TestCase("#FF002B")]
-        //    YCbCrColor yCbCrColor = YCbCrColor.FromColor(color);
+        [TestCase("#00ABFF")]
-        //    string result = ColorTranslator.ToHtml(yCbCrColor);
+        public void TestYCbCrConversion(string expected)
-        //    Assert.AreEqual(expected, result);
+        {
-        //}
+            Color color = ColorTranslator.FromHtml(expected);
+            YCbCrColor yCbCrColor = YCbCrColor.FromColor(color);
+            string result = ColorTranslator.ToHtml(yCbCrColor);
+            Assert.AreEqual(expected, result);
+        }
     }
 }

src/ImageProcessor/Common/Extensions/DoubleExtensions.cs

@@ -10,6 +10,8 @@
 
 namespace ImageProcessor.Common.Extensions
 {
+    using System;
+
     /// <summary>
     /// Encapsulates a series of time saving extension methods to the <see cref="T:System.Double"/> class.
     /// </summary>
@@ -30,7 +32,7 @@ namespace ImageProcessor.Common.Extensions
         /// </returns>
         public static byte ToByte(this double d)
         {
-            return (byte)((d > byte.MaxValue) ? byte.MaxValue : ((d < byte.MinValue) ? byte.MinValue : d));
+            return Convert.ToByte(Math.Max(0.0d, Math.Min(255d, d))); // ((d > byte.MaxValue) ? byte.MaxValue : ((d < byte.MinValue) ? byte.MinValue : d));
         }
     }
 }

src/ImageProcessor/Imaging/Colors/HSLAColor.cs

@@ -84,6 +84,7 @@ namespace ImageProcessor.Imaging.Colors
 
         /// <summary>
         /// Gets the hue component.
+        /// <remarks>A value ranging between 0 and 1.</remarks>
         /// </summary>
         public float H
         {
@@ -95,6 +96,7 @@ namespace ImageProcessor.Imaging.Colors
 
         /// <summary>
         /// Gets the luminosity component.
+        /// <remarks>A value ranging between 0 and 1.</remarks>
         /// </summary>
         public float L
         {
@@ -106,6 +108,7 @@ namespace ImageProcessor.Imaging.Colors
 
         /// <summary>
         /// Gets the saturation component.
+        /// <remarks>A value ranging between 0 and 1.</remarks>
         /// </summary>
         public float S
         {
@@ -117,6 +120,7 @@ namespace ImageProcessor.Imaging.Colors
 
         /// <summary>
         /// Gets the alpha component.
+        /// <remarks>A value ranging between 0 and 1.</remarks>
         /// </summary>
         public float A
         {
@@ -197,17 +201,11 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         public static implicit operator HslaColor(Color color)
         {
-            HslaColor hslColor = new HslaColor(
+            return FromColor(color);
-                  color.GetHue() / 360.0f,
-                  color.GetSaturation(),
-                  color.GetBrightness(),
-                  color.A / 255f);
-
-            return hslColor;
         }
 
         /// <summary>
-        /// Allows the implicit conversion of an instance of <see cref="System.Drawing.Color"/> to a 
+        /// Allows the implicit conversion of an instance of <see cref="RgbaColor"/> to a 
         /// <see cref="HslaColor"/>.
         /// </summary>
         /// <param name="rgbaColor">
@@ -218,14 +216,22 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         public static implicit operator HslaColor(RgbaColor rgbaColor)
         {
-            Color color = rgbaColor;
+            return FromColor(rgbaColor);
-            HslaColor hslColor = new HslaColor(
+        }
-                color.GetHue() / 360.0f,
+
-                color.GetSaturation(),
+        /// <summary>
-                color.GetBrightness(),
+        /// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a 
-                color.A / 255f);
+        /// <see cref="HslaColor"/>.
-
+        /// </summary>
-            return hslColor;
+        /// <param name="ycbcrColor">
+        /// The instance of <see cref="YCbCrColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="YCbCrColor"/>.
+        /// </returns>
+        public static implicit operator HslaColor(YCbCrColor ycbcrColor)
+        {
+            return FromColor(ycbcrColor);
         }
 
         /// <summary>
@@ -277,29 +283,22 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         public static implicit operator RgbaColor(HslaColor hslaColor)
         {
-            float r = 0, g = 0, b = 0;
+            return RgbaColor.FromColor(hslaColor);
-            if (Math.Abs(hslaColor.l - 0) > .0001)
+        }
-            {
-                if (Math.Abs(hslaColor.s - 0) <= .0001)
-                {
-                    r = g = b = hslaColor.l;
-                }
-                else
-                {
-                    float temp2 = GetTemp2(hslaColor);
-                    float temp1 = (2.0f * hslaColor.l) - temp2;
-
-                    r = GetColorComponent(temp1, temp2, hslaColor.h + (1.0f / 3.0f));
-                    g = GetColorComponent(temp1, temp2, hslaColor.h);
-                    b = GetColorComponent(temp1, temp2, hslaColor.h - (1.0f / 3.0f));
-                }
-            }
 
-            return RgbaColor.FromRgba(
+        /// <summary>
-                Convert.ToByte(255 * r),
+        /// Allows the implicit conversion of an instance of <see cref="HslaColor"/> to a 
-                Convert.ToByte(255 * g),
+        /// <see cref="YCbCrColor"/>.
-                Convert.ToByte(255 * b),
+        /// </summary>
-                Convert.ToByte(255 * hslaColor.a));
+        /// <param name="hslaColor">
+        /// The instance of <see cref="HslaColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="YCbCrColor"/>.
+        /// </returns>
+        public static implicit operator YCbCrColor(HslaColor hslaColor)
+        {
+            return YCbCrColor.FromColor(hslaColor);
         }
 
         /// <summary>

src/ImageProcessor/Imaging/Colors/RGBAColor.cs

@@ -191,22 +191,37 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         public static implicit operator RgbaColor(Color color)
         {
-            return new RgbaColor(color);
+            return FromColor(color);
         }
 
         /// <summary>
-        /// Allows the implicit conversion of an instance of <see cref="System.Drawing.Color"/> to a 
+        /// Allows the implicit conversion of an instance of <see cref="HslaColor"/> to a 
         /// <see cref="RgbaColor"/>.
         /// </summary>
-        /// <param name="color">
+        /// <param name="hslaColor">
-        /// The instance of <see cref="System.Drawing.Color"/> to convert.
+        /// The instance of <see cref="HslaColor"/> to convert.
         /// </param>
         /// <returns>
         /// An instance of <see cref="RgbaColor"/>.
         /// </returns>
-        public static implicit operator RgbaColor(HslaColor color)
+        public static implicit operator RgbaColor(HslaColor hslaColor)
         {
-            return new RgbaColor(color);
+            return FromColor(hslaColor);
+        }
+
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a 
+        /// <see cref="RgbaColor"/>.
+        /// </summary>
+        /// <param name="ycbcrColor">
+        /// The instance of <see cref="YCbCrColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="RgbaColor"/>.
+        /// </returns>
+        public static implicit operator RgbaColor(YCbCrColor ycbcrColor)
+        {
+            return FromColor(ycbcrColor);
         }
 
         /// <summary>
@@ -239,6 +254,21 @@ namespace ImageProcessor.Imaging.Colors
             return HslaColor.FromColor(rgba);
         }
 
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="RgbaColor"/> to a 
+        /// <see cref="YCbCrColor"/>.
+        /// </summary>
+        /// <param name="rgba">
+        /// The instance of <see cref="RgbaColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="YCbCrColor"/>.
+        /// </returns>
+        public static implicit operator YCbCrColor(RgbaColor rgba)
+        {
+            return YCbCrColor.FromColor(rgba);
+        }
+
         /// <summary>
         /// Returns a <see cref="System.String" /> that represents this instance.
         /// </summary>

src/ImageProcessor/Imaging/Colors/YCbCrColor.cs

@@ -4,7 +4,7 @@
 //   Licensed under the Apache License, Version 2.0.
 // </copyright>
 // <summary>
-//   Represents an YCbCr (luminance, chroma, chroma) color used in digital imaging systems.
+//   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" />
 // </summary>
 // --------------------------------------------------------------------------------------------------------------------
@@ -14,10 +14,8 @@ namespace ImageProcessor.Imaging.Colors
     using System;
     using System.Drawing;
 
-    using ImageProcessor.Common.Extensions;
-
     /// <summary>
-    /// Represents an YCbCr (luminance, chroma, chroma) color used in digital imaging systems.
+    /// 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"/>
     /// </summary>
     public struct YCbCrColor
@@ -50,13 +48,14 @@ namespace ImageProcessor.Imaging.Colors
         /// <param name="cr">The v chroma component.</param> 
         private YCbCrColor(float y, float cb, float cr)
         {
-            this.y = y; //Math.Max(0.0f, Math.Min(1.0f, y));
+            this.y = Math.Max(0f, Math.Min(255f, y));
-            this.cb = cb; //Math.Max(-0.5f, Math.Min(0.5f, cb));
+            this.cb = Math.Max(-255f, Math.Min(255f, cb));
-            this.cr = cr; //Math.Max(-0.5f, Math.Min(0.5f, cr));
+            this.cr = Math.Max(-255f, Math.Min(255f, cr));
         }
 
         /// <summary>
         /// Gets the Y luminance component.
+        /// <remarks>A value ranging between 0 and 255.</remarks>
         /// </summary>
         public float Y
         {
@@ -68,23 +67,25 @@ namespace ImageProcessor.Imaging.Colors
 
         /// <summary>
         /// Gets the U chroma component.
+        /// <remarks>A value ranging between -255 and 255.</remarks>
         /// </summary>
         public float Cb
         {
             get
             {
-                return this.y;
+                return this.cb;
             }
         }
 
         /// <summary>
         /// Gets the V chroma component.
+        /// <remarks>A value ranging between -255 and 255.</remarks>
         /// </summary>
         public float Cr
         {
             get
             {
-                return this.y;
+                return this.cr;
             }
         }
 
@@ -114,12 +115,12 @@ namespace ImageProcessor.Imaging.Colors
         /// </returns>
         public static YCbCrColor FromColor(Color color)
         {
-            float r = color.R;
+            byte r = color.R;
-            float g = color.G;
+            byte g = color.G;
-            float b = color.B;
+            byte b = color.B;
 
             float y = (float)((0.299 * r) + (0.587 * g) + (0.114 * b));
-            float cb = 128 - (float)((-0.168736 * r) - (0.331264 * g) + (0.5 * b));
+            float cb = 128 + (float)((-0.168736 * r) - (0.331264 * g) + (0.5 * b));
             float cr = 128 + (float)((0.5 * r) - (0.418688 * g) - (0.081312 * b));
 
             return new YCbCrColor(y, cb, cr);
@@ -140,24 +141,148 @@ namespace ImageProcessor.Imaging.Colors
             return FromColor(color);
         }
 
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="RgbaColor"/> to a 
+        /// <see cref="YCbCrColor"/>.
+        /// </summary>
+        /// <param name="rgbaColor">
+        /// The instance of <see cref="RgbaColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="YCbCrColor"/>.
+        /// </returns>
+        public static implicit operator YCbCrColor(RgbaColor rgbaColor)
+        {
+            return FromColor(rgbaColor);
+        }
+
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="HslaColor"/> to a 
+        /// <see cref="YCbCrColor"/>.
+        /// </summary>
+        /// <param name="hslaColor">
+        /// The instance of <see cref="HslaColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="YCbCrColor"/>.
+        /// </returns>
+        public static implicit operator YCbCrColor(HslaColor hslaColor)
+        {
+            return FromColor(hslaColor);
+        }
+
         /// <summary>
         /// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a 
         /// <see cref="System.Drawing.Color"/>.
         /// </summary>
-        /// <param name="ycbcr">
+        /// <param name="ycbcrColor">
         /// The instance of <see cref="YCbCrColor"/> to convert.
         /// </param>
         /// <returns>
         /// An instance of <see cref="System.Drawing.Color"/>.
         /// </returns>
-        public static implicit operator Color(YCbCrColor ycbcr)
+        public static implicit operator Color(YCbCrColor ycbcrColor)
         {
-            byte r = Convert.ToInt32(ycbcr.Y + (1.402 * (ycbcr.Cr - 128))).ToByte();
+            float y = ycbcrColor.Y;
-            byte g = Convert.ToInt32(ycbcr.Y - (0.34414 * (ycbcr.Cb - 128)) - (0.71414 * (ycbcr.Cr - 128))).ToByte();
+            float cb = ycbcrColor.Cb - 128;
-            byte b = Convert.ToInt32(ycbcr.Y + (1.772 * (ycbcr.Cb - 128))).ToByte();
+            float cr = ycbcrColor.Cr - 128;
-            
+
+            byte r = Convert.ToByte(Math.Max(0.0f, Math.Min(255f, y + (1.402 * cr))));
+            byte g = Convert.ToByte(Math.Max(0.0f, Math.Min(255f, y - (0.34414 * cb) - (0.71414 * cr))));
+            byte b = Convert.ToByte(Math.Max(0.0f, Math.Min(255f, y + (1.772 * cb))));
 
             return Color.FromArgb(255, r, g, b);
         }
+
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a 
+        /// <see cref="RgbaColor"/>.
+        /// </summary>
+        /// <param name="ycbcrColor">
+        /// The instance of <see cref="YCbCrColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="RgbaColor"/>.
+        /// </returns>
+        public static implicit operator RgbaColor(YCbCrColor ycbcrColor)
+        {
+            return RgbaColor.FromColor(ycbcrColor);
+        }
+
+        /// <summary>
+        /// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a 
+        /// <see cref="HslaColor"/>.
+        /// </summary>
+        /// <param name="ycbcrColor">
+        /// The instance of <see cref="YCbCrColor"/> to convert.
+        /// </param>
+        /// <returns>
+        /// An instance of <see cref="HslaColor"/>.
+        /// </returns>
+        public static implicit operator HslaColor(YCbCrColor ycbcrColor)
+        {
+            return HslaColor.FromColor(ycbcrColor);
+        }
+
+        /// <summary>
+        /// Returns a <see cref="System.String" /> that represents this instance.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="System.String" /> that represents this instance.
+        /// </returns>
+        public override string ToString()
+        {
+            if (this.IsEmpty())
+            {
+                return "YCbCrColor [Empty]";
+            }
+
+            return string.Format("YCbCrColor [ Y={0:#0.##}, Cb={1:#0.##}, Cr={2:#0.##}]", this.Y, this.Cb, this.Cr);
+        }
+
+        /// <summary>
+        /// Indicates whether this instance and a specified object are equal.
+        /// </summary>
+        /// <returns>
+        /// true if <paramref name="obj"/> and this instance are the same type and represent the same value; otherwise, false.
+        /// </returns>
+        /// <param name="obj">Another object to compare to. </param>
+        public override bool Equals(object obj)
+        {
+            if (obj is YCbCrColor)
+            {
+                Color thisColor = this;
+                Color otherColor = (YCbCrColor)obj;
+
+                return thisColor.Equals(otherColor);
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Returns the hash code for this instance.
+        /// </summary>
+        /// <returns>
+        /// A 32-bit signed integer that is the hash code for this instance.
+        /// </returns>
+        public override int GetHashCode()
+        {
+            Color thisColor = this;
+            return thisColor.GetHashCode();
+        }
+
+        /// <summary>
+        /// Returns a value indicating whether the current instance is empty.
+        /// </summary>
+        /// <returns>
+        /// The true if this instance is empty; otherwise, false.
+        /// </returns>
+        private bool IsEmpty()
+        {
+            const float Epsilon = .0001f;
+            return Math.Abs(this.y - 0) <= Epsilon && Math.Abs(this.cb - 0) <= Epsilon &&
+                   Math.Abs(this.cr - 0) <= Epsilon;
+        }
     }
 }