Added Duv computation

Author: castarco

CHANGELOG.md

@@ -1,11 +1,17 @@
 ColorSharp's Changelog
 ======================
 
-## 2015-02-25 : 0.10.0 Release
+## 2015-02-26 : 0.11.0 Release
 
 ### Contributors
  * Andrés Correa Casablanca <[email protected] , [email protected]>
 
+### Changes
+ * Added CCT (Correlated Color Temparature) computation.
+ * Added Duv (Distance on CIE's 1960 UCS/Yuv color space) computation.
+
+## 2015-02-25 : 0.10.0 Release
+
 ### Project Handling
  * Until we have more contributors, removed the references to contributors for
    every release in the CHANGELOG file.

ColorSharp.sln

@@ -33,6 +33,6 @@ Global
 		$0.VersionControlPolicy = $2
 		$2.inheritsSet = Mono
 		description = A .Net/Mono library to handle color spaces (and light spectrums!)
-		version = 0.10.0
+		version = 0.11.0
 	EndGlobalSection
 EndGlobal

ColorSharp/ColorSharp.csproj

@@ -11,7 +11,7 @@
     <SignAssembly>true</SignAssembly>
     <DelaySign>true</DelaySign>
     <AssemblyOriginatorKeyFile>colorsharp.pub</AssemblyOriginatorKeyFile>
-    <ReleaseVersion>0.10.0</ReleaseVersion>
+    <ReleaseVersion>0.11.0</ReleaseVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

ColorSharp/ColorSharp.nuspec

@@ -11,11 +11,8 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>$description$</description>
     <releaseNotes>
-- Added new Illuminants
-- Added new Matching Functions
-- Improved spectrum -> color conversion mechanism
-- Added black body spectrums
-- Minor API breaks.
+- Added CCT computation.
+- Added Duv computation.
     </releaseNotes>
     <copyright>Copyright 2014-2015</copyright>
     <tags>Light Color Colour CIEXYZ CIExyY sRGB</tags>

ColorSharp/src/ColorSpaces/AConvertibleColor.cs

@@ -137,6 +137,15 @@ public virtual double GetCCT ()
 				return ToCIEUCS ().GetCCT ();
 			}
 
+			public virtual double GetDuv ()
+			{
+				if (DataSource is BlackBodySpectrum) {
+					return 0;
+				}
+
+				return ToCIEUCS ().GetDuv ();
+			}
+
 			/**
 			 * <summary>Converts the color sample to a CIE's 1931 XYZ color sample.</summary>
 			 */

ColorSharp/src/ColorSpaces/CIEUCS.cs

@@ -79,6 +79,10 @@ public sealed class CIEUCS : AConvertibleColor
 
 			static List<CIEUCS> TemperatureChromaticities = null;
 
+			double CCT = double.NaN;
+
+			double Duv = double.NaN;
+
 			#endregion
 
 
@@ -188,6 +192,11 @@ public override double GetCCT ()
 					return (DataSource as BlackBodySpectrum).CCT;
 				}
 
+				if (!double.IsNaN (CCT)) {
+					return CCT;
+				}
+
+				// Precomputing interpolation tables...
 				if (TemperatureChromaticities == null) {
 					// Oversized to improve alignment (needs 302).
 					TemperatureChromaticities = new List<CIEUCS> (512);
@@ -201,7 +210,7 @@ public override double GetCCT ()
 				}
 
 				int bestI = 0;
-				double minDuv = double.PositiveInfinity;
+				Duv = double.PositiveInfinity;
 
 				// First gross grained search
 				// TODO: This is a naive search, must be improved!
@@ -211,12 +220,12 @@ public override double GetCCT ()
 		                Math.Pow (v - TemperatureChromaticities [i].v, 2)
 	                );
 
-					if (minDuv > tmpDuv) {
-						minDuv = tmpDuv;
+					if (Duv > tmpDuv) {
+						Duv = tmpDuv;
 						bestI = i;
 					}
 				}
-				double bestTmp = TemperatureChromaticities [bestI].GetCCT ();
+				CCT = TemperatureChromaticities [bestI].GetCCT ();
 
 				// Preparing the following fine grained search
 				double tMin = TemperatureChromaticities [
@@ -233,13 +242,26 @@ public override double GetCCT ()
 
 					double tmpDuv = Math.Sqrt (Math.Pow (u - tmpUV.u, 2) +	Math.Pow (v - tmpUV.v, 2));
 
-					if (minDuv > tmpDuv) {
-						minDuv = tmpDuv;
-						bestTmp = t;
+					if (Duv > tmpDuv) {
+						Duv = tmpDuv;
+						CCT = t;
 					}
 				}
 
-				return bestTmp;
+				return CCT;
+			}
+
+			public override double GetDuv ()
+			{
+				if (DataSource is BlackBodySpectrum) {
+					return 0;
+				}
+
+				if (double.IsNaN (Duv)) {
+					GetCCT ();
+				}
+
+				return Duv;
 			}
 
 			/**

ColorSharp/src/LightSpectrums/BlackBodySpectrum.cs

@@ -121,6 +121,14 @@ public override double GetCCT ()
 				return CCT;
 			}
 
+			/**
+			 * <inheritdoc />
+			 */
+			public override double GetDuv ()
+			{
+				return 0;
+			}
+
 			#endregion
 		}
 	}

ColorSharpTests/ColorSharpTests.csproj

@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>Litipk.ColorSharpTests</RootNamespace>
     <AssemblyName>ColorSharpTests</AssemblyName>
-    <ReleaseVersion>0.10.0</ReleaseVersion>
+    <ReleaseVersion>0.11.0</ReleaseVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

TODO.md

@@ -32,11 +32,11 @@
   * [ ] Color Rendering Index (CRI)
 
 ### Colors
-  * [ ] Color Temperature
+  * [X] Color Temperature
 
 ## Color Operations
-  * IsAdditive : bool
-  * colorC = colorA + colorB
+  * [ ] IsAdditive : bool
+  * [ ] colorC = colorA + colorB
 
 ## Performance
   * [ ] Make use of OpenCL to improve conversions performance (with OpenCL.NET?)