private Bitmap DrawBitmap(string model)
{
var gamut = CIE1931Gamut.ForModel(model);
int dimension = 500;
Bitmap b = new Bitmap(dimension, dimension);
for (int x = 0; x < dimension; x++)
{
for (int y = 0; y < dimension; y++)
{
CIE1931Point point = new CIE1931Point(x / (dimension * 1.0), y / (dimension * 1.0));
var rgb = HueColorConverter.XYToRgb(point, model);
Color c;
if (point.x + point.y > 1.0)
{
c = Color.Black;
}
else if (gamut.Contains(point))
{
c = Color.FromArgb((int)(rgb.R * 255.999), (int)(rgb.G * 255.999), (int)(rgb.B * 255.999));
}
else
{
c = Color.FromArgb((int)(rgb.R * 127.999), (int)(rgb.G * 127.999), (int)(rgb.B * 127.999));
}
// CIE1931 charts are drawn with y-increasing being upwards, not downwards as in bitmaps.
b.SetPixel(x, (dimension - 1) - y, c);
}
}
return(b);
}
public void ColorConversionRoundtripAllPoints()
{
// Use a consistent seed for test reproducability
Random r = new Random(0);
for (int trial = 0; trial < 1000; trial++)
{
CIE1931Point originalXy;
// Randomly generate a test color that is at a valid CIE1931 coordinate.
do
{
originalXy = new CIE1931Point(r.NextDouble(), r.NextDouble());
}while (originalXy.x + originalXy.y >= 1.0);
RGBColor rgb = HueColorConverter.XYToRgb(originalXy, "LCT001");
var xy = HueColorConverter.RgbToXY(rgb, "LCT001");
// We expect a point that is both inside the lamp's gamut and the "wide gamut"
// used for XYZ->RGB and RGB->XYZ conversion.
// Conversion from XY to RGB
var expectedXy = CIE1931Gamut.ForModel("LCT001").NearestContainedPoint(originalXy);
expectedXy = CIE1931Gamut.PhilipsWideGamut.NearestContainedPoint(expectedXy);
// RGB to XY
expectedXy = CIE1931Gamut.ForModel("LCT001").NearestContainedPoint(expectedXy);
AssertAreEqual(expectedXy, xy, 0.0001);
}
}
public void GamutContainsWorksCorrectly()
{
Random r = new Random(0);
for (int trial = 0; trial < 1000; trial++)
{
var point = new CIE1931Point(r.NextDouble(), r.NextDouble());
var gamutB = CIE1931Gamut.ForModel("LCT001");
Assert.AreEqual(ReferenceColorConverter.CheckPointInLampsReach(point), gamutB.Contains(point));
}
}
public void ColorsOutsideGamutAdjustedToInBeInGamut()
{
// This green is in the gamut of LST001, but not LCT001.
CIE1931Point outsideGreen = new CIE1931Point(0.18, 0.72);
CIE1931Point gamutAGreen = new CIE1931Point(0.2151, 0.7106);
CIE1931Point gamutBGreen = new CIE1931Point(0.409, 0.518);
CIE1931Point gamutCGreen = new CIE1931Point(0.17, 0.7);
AssertAreEqual(gamutAGreen, CIE1931Gamut.ForModel("LST001").NearestContainedPoint(outsideGreen), 0.0001);
AssertAreEqual(gamutBGreen, CIE1931Gamut.ForModel("LCT001").NearestContainedPoint(outsideGreen), 0.0001);
AssertAreEqual(gamutCGreen, CIE1931Gamut.ForModel("LST002").NearestContainedPoint(outsideGreen), 0.0001);
}
public void ColorsOutsideGamutAdjustedToInBeInGamutOnConversion()
{
// The green primary of Gamut A.
CIE1931Point gamutGreen = new CIE1931Point(0.2151, 0.7106);
// A color green outside Gamut A.
CIE1931Point greenOutsideGamut = new CIE1931Point(0.21, 0.75);
var a = HueColorConverter.XYToRgb(gamutGreen, CIE1931Gamut.ForModel("LST001"));
var b = HueColorConverter.XYToRgb(greenOutsideGamut, CIE1931Gamut.ForModel("LST001"));
// Points should be equal, since the green outside the gamut should
// be adjusted the the nearest green in-gamut.
Assert.AreEqual(a.R, b.R);
Assert.AreEqual(a.G, b.G);
Assert.AreEqual(a.B, b.B);
}
public void ColorConversionWhitePoint()
{
// These light models are capable of Gamuts A, B and C respectively.
// See http://www.developers.meethue.com/documentation/supported-lights
string[] models = new string[] { "LST001", "LCT001", "LST002" };
foreach (string model in models)
{
// Make sure that Philips' white point resolves to #FFFFFF for all lights.
var rgb = HueColorConverter.XYToRgb(CIE1931Point.PhilipsWhite, CIE1931Gamut.ForModel(model));
Assert.AreEqual(rgb.R, 1.0, 0.0001);
Assert.AreEqual(rgb.G, 1.0, 0.0001);
Assert.AreEqual(rgb.B, 1.0, 0.0001);
var xy = HueColorConverter.RgbToXY(new RGBColor(1.0, 1.0, 1.0), CIE1931Gamut.ForModel(model));
AssertAreEqual(CIE1931Point.PhilipsWhite, xy, 0.0001);
}
}
public void ColorConversionRoundtripInsideGamut()
{
// Use a consistent seed for test reproducability
Random r = new Random(0);
for (int trial = 0; trial < 1000; trial++)
{
CIE1931Point originalXy;
// Randomly generate a test color that is at a valid CIE1931 coordinate.
do
{
originalXy = new CIE1931Point(r.NextDouble(), r.NextDouble());
}while (originalXy.x + originalXy.y >= 1.0 ||
!ReferenceColorConverter.CheckPointInLampsReach(originalXy) ||
!CIE1931Gamut.PhilipsWideGamut.Contains(originalXy));
RGBColor rgb = HueColorConverter.XYToRgb(originalXy, CIE1931Gamut.ForModel("LCT001"));
var xy = HueColorConverter.RgbToXY(rgb, CIE1931Gamut.ForModel("LCT001"));
AssertAreEqual(originalXy, xy, 0.0001);
}
}
public void CompareColorConversionWithReference()
{
// Use a consistent seed for test reproducability
Random r = new Random(0);
for (int trial = 0; trial < 1000; trial++)
{
double red = r.NextDouble();
double green = r.NextDouble();
double blue = r.NextDouble();
var referenceXy = ReferenceColorConverter.XyFromColor(red, green, blue);
// LCT001 uses Gamut B, which is the gamut used in the reference implementation.
var actualXy = HueColorConverter.RgbToXY(new RGBColor(red, green, blue), CIE1931Gamut.ForModel("LCT001"));
AssertAreEqual(referenceXy, actualXy, 0.0001);
}
}