/// <summary>
/// transformatin CIE L*u*v* -> CIE XYZ
/// </summary>
/// <author>Birthe Anne Wiegand</author>
/// <returns>XYZ value</returns>
public XYZ asXYZ(XYZ WP)
{
XYZ temp = new XYZ();
float temp_u = new float();
float temp_v = new float();
temp_u = this.U / (13f * this.L) + ColorHelper.function_XYZ_to_LUV(WP)[0];
temp_v = this.V / (13f * this.L) + ColorHelper.function_XYZ_to_LUV(WP)[1];
if (this.L <= 8)
{
temp.Y = WP.Y * this.L * 0.001107056f;
}
else
{
temp.Y = WP.Y * (float)Math.Pow(((this.L + 16f) / 116f), 3f);
}
temp.X = temp.Y * 9f * temp_u / (4f * temp_v);
temp.Z = temp.Y * (12f - 3f * temp_u - 20f * temp_v) / (4f * temp_v);
// to catch the otherwise occuring exception for L = 0 (black -> no color information)
// X and Z are given the value 0 just for interface clarity as there is no information given about them.
// (so 0 is as good as any other value, but does not imply anything wrong)
if (float.IsNaN(temp.X)) temp.X = 0f;
if (float.IsNaN(temp.Z)) temp.Z = 0f;
return temp;
}
/// <summary>
/// transformatin CIE L*a*b* -> CIE XYZ
/// </summary>
/// <author>Birthe Anne Wiegand</author>
/// <returns>XYZ value</returns>
public XYZ asXYZ(XYZ WP)
{
XYZ temp = new XYZ();
temp.Y = WP.Y * function_LAB_to_XYZ((this.L + 16f) / 116f);
temp.X = WP.X * function_LAB_to_XYZ((this.L + 16f) / 116f + this.A / 500);
temp.Z = WP.Z * function_LAB_to_XYZ((this.L + 16f) / 116f - this.B / 200);
return temp;
}
public XYZ asXYZ()
{
XYZ temp = new XYZ();
// transformation Yxy -> CIE XYZ
float normalizeFactor = this.Y / this.y;
float Z = (1 - this.x - this.y) * normalizeFactor;
temp.X = this.x * normalizeFactor;
temp.Y = this.Y;
temp.Z = Z;
return temp;
}
public static float Chromatic_Difference(XYZ input1, XYZ input2)
{
// returns the chromatic difference of two colors given in the XYZ format
// using the euclidean distance on the u' and v' values
// (e.g. needed for the just noticeable difference (JND) calculation)
// source: http://files.cie.co.at/738_CIE_TN_001-2014.pdf
float temp = new float();
Vector2 input1_vector = new Vector2();
Vector2 input2_vector = new Vector2();
input1_vector = function_XYZ_to_LUV(input1);
input2_vector = function_XYZ_to_LUV(input2);
temp = (float)Math.Sqrt((float)Math.Pow((input2_vector[0] - input1_vector[0]), 2f) + (float)Math.Pow((input2_vector[1] - input1_vector[1]), 2f));
return temp;
}
/// <summary>
/// this calclates the u' and v' values for a given XYZ value
/// outsourced because it is used by more than one color class (mostly for L*u*v*, hence the name)
/// source: http://en.wikipedia.org/wiki/CIELUV (checked with various google results, this was the most consistent one)
/// </summary>
/// <author>Birthe Anne Wiegand</author>
/// <returns>a vector with u' in its first argument ([0]) and v' in the second ([1]), both floats</returns>
public static Vector2 function_XYZ_to_LUV(XYZ input)
{
// calculates the u' and v' values for a given XYZ value
// (needed for the transformation CIE XYZ -> CIE L*u*v* and back)
// [0] gives the u' value and [1] the v' value
Vector2 temp = new Vector2();
temp[0] = (4f * input.X) / (input.X + 15f * input.Y + 3f * input.Z);
temp[1] = (9f * input.Y) / (input.X + 15f * input.Y + 3f * input.Z);
return temp;
}
/// <summary>
/// (re-)sets (to) init values
/// </summary>
/// <author>Markus Strobel</author>
private void setInitValues()
{
WP_default = WP_used = new XYZ(0.95045596f, 1f, 1.0890577f);
RR_default = RR_used = new XYZ(0.64f, 0.33f, 0.03f);
GG_default = GG_used = new XYZ(0.30f, 0.60f, 0.10f);
BB_default = BB_used = new XYZ(0.15f, 0.06f, 0.79f);
TranformationMatrices_Update();
}
/// <summary>
/// </summary>
/// <author> Birthe Anne Wiegand</author>
private void ResetColorValues()
{
// set color values to 0
RGBvalue = new RGB();
customRGBvalue = new customRGB();
sRGBvalue = new sRGB();
HSLvalue = new HSL();
HSVvalue = new HSV();
XYZvalue = new XYZ();
LUVvalue = new LUV();
LABvalue = new LAB();
UpdateBoxes();
}
/// <summary>
/// this method performs all tasks done with a left mouse click in XYZ space
/// </summary>
/// <param name="x">the current x coordinate</param>
/// <param name="y">the current y coordinate</param>
/// <param name="showCircle">if true the selected Color circle will be shown</param>
/// <author>Markus Strobel</author>
private void LeftClickXYZSpace(float x, float y, bool showCircle)
{
// set trackbar values
if (!(hoveredRGBColor.R < 0 || hoveredRGBColor.G < 0 || hoveredRGBColor.B < 0))
{
HSL hsl = hoveredRGBColor.asHSL();
// normalize
float maxV = Math.Max(hoveredRGBColor.R, Math.Max(hoveredRGBColor.G, hoveredRGBColor.B));
hoveredRGBColor.R /= maxV;
hoveredRGBColor.G /= maxV;
hoveredRGBColor.B /= maxV;
// set RGB tab values for trackbars
labelTabRGB_R.Text = "R: " + hoveredRGBColor.R;
labelTabRGB_G.Text = "G: " + hoveredRGBColor.G;
labelTabRGB_B.Text = "B: " + hoveredRGBColor.B;
trackBarR.Value = (int)(hoveredRGBColor.R * 255);
trackBarG.Value = (int)(hoveredRGBColor.G * 255);
trackBarB.Value = (int)(hoveredRGBColor.B * 255);
//set HSL values for trackbars
labelTabHSL_H.Text = "H: " + (hsl.H) + "°";
labelTabHSL_S.Text = "S: " + (hsl.S * 100) + "%";
labelTabHSL_L.Text = "L: " + (hsl.L * 100) + "%";
trackBarH.Value = (int)hsl.H;
trackBarS.Value = (int)(hsl.S * 100);
trackBarL.Value = (int)(hsl.L * 100);
selectedRGBColor = hoveredRGBColor;
selectedXYZColor = hoveredXYZColor;
selectedYxyColor = new Yxy(x, y);
if (checkBoxRGB.Checked)
{
showColorCircle = false;
createRGBPreviewLines(selectedRGBColor);
}
else if (checkBoxHSL.Checked)
{
showColorCircle = false;
createHSLPreviewLines(selectedRGBColor.asHSL());
createHSLPreviewCircle(selectedRGBColor.asHSL());
}
else
{
showColorCircle = showCircle;
createSelectedColorCircleVBO(x, y, 0.01f, 36); // computes color circle position
}
}
else // (!(hoveredRGBColor.R < 0 || hoveredRGBColor.G < 0 || hoveredRGBColor.B < 0))
{
trackBarR.Value = 0;
trackBarG.Value = 0;
trackBarB.Value = 0;
labelTabRGB_R.Text = "R: 0";
labelTabRGB_G.Text = "G: 0";
labelTabRGB_B.Text = "B: 0";
trackBarH.Value = 1;
trackBarS.Value = 100;
trackBarL.Value = 50;
labelTabHSL_H.Text = "H: 1°";
labelTabHSL_S.Text = "S: 100%";
labelTabHSL_L.Text = "L: 50%";
selectedRGBColor = null;
selectedXYZColor = null;
showColorCircle = false;
}
// take current preview Color as selected Color
// we dont need to compute it twice
// set selectedColor Panel, label
panelColorSelected.BackColor = panelColorPreview.BackColor;
labelColorSelectedHex.Text = labelColorPreviewHex.Text;
labelColSelectedXH.Text = labelColPreviewXH.Text;
labelColSelectedYS.Text = labelColPreviewYS.Text;
}
/// <summary>
/// </summary>
/// <author> Birthe Anne Wiegand</author>
private void KonvertierenButton_Click(object sender, EventArgs e)
{
RadioButton checkedButton = this.tabFarbRechner.Controls.OfType<RadioButton>().FirstOrDefault(radioButton => radioButton.Checked);
switch (checkedButton.Name)
{
case "customRGB":
// parse input to internal customRGBvalue
customRGBvalue.R = float.Parse(customRGB_R.Text, CultureInfo.InvariantCulture);
customRGBvalue.G = float.Parse(customRGB_G.Text, CultureInfo.InvariantCulture);
customRGBvalue.B = float.Parse(customRGB_B.Text, CultureInfo.InvariantCulture);
// update other internal values
XYZvalue = customRGBvalue.asXYZ();
RGBvalue = XYZvalue.asRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSLvalue = RGBvalue.asHSL();
HSVvalue = RGBvalue.asHSV();
LUVvalue = XYZvalue.asLUV();
LABvalue = XYZvalue.asLAB();
break;
case "sRGB":
// parse input to internal customRGBvalue
sRGBvalue.R = float.Parse(sRGB_R.Text, CultureInfo.InvariantCulture);
sRGBvalue.G = float.Parse(sRGB_G.Text, CultureInfo.InvariantCulture);
sRGBvalue.B = float.Parse(sRGB_B.Text, CultureInfo.InvariantCulture);
// update other internal values
RGBvalue = sRGBvalue.asRGB();
XYZvalue = RGBvalue.asXYZ();
customRGBvalue = XYZvalue.as_customRGB();
HSLvalue = RGBvalue.asHSL();
HSVvalue = RGBvalue.asHSV();
LUVvalue = XYZvalue.asLUV();
LABvalue = XYZvalue.asLAB();
break;
case "HSL":
// parse input to internal HSLvalue
HSLvalue.H = float.Parse(HSL_H.Text, CultureInfo.InvariantCulture);
HSLvalue.S = float.Parse(HSL_S.Text, CultureInfo.InvariantCulture);
HSLvalue.L = float.Parse(HSL_L.Text, CultureInfo.InvariantCulture);
// update other internal values
RGBvalue = HSLvalue.asRGB();
XYZvalue = RGBvalue.asXYZ();
customRGBvalue = XYZvalue.as_customRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSVvalue = RGBvalue.asHSV();
LUVvalue = XYZvalue.asLUV();
LABvalue = XYZvalue.asLAB();
break;
case "HSV":
// parse input to internal HSVvalue
HSVvalue.H = float.Parse(HSV_H.Text, CultureInfo.InvariantCulture);
HSVvalue.S = float.Parse(HSV_S.Text, CultureInfo.InvariantCulture);
HSVvalue.V = float.Parse(HSV_V.Text, CultureInfo.InvariantCulture);
// update other internal values
RGBvalue = HSVvalue.asRGB();
XYZvalue = RGBvalue.asXYZ();
customRGBvalue = XYZvalue.as_customRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSLvalue = RGBvalue.asHSL();
LUVvalue = XYZvalue.asLUV();
LABvalue = XYZvalue.asLAB();
break;
case "XYZ":
// parse input to internal HSVvalue
XYZvalue.X = float.Parse(XYZ_X.Text, CultureInfo.InvariantCulture);
XYZvalue.Y = float.Parse(XYZ_Y.Text, CultureInfo.InvariantCulture);
XYZvalue.Z = float.Parse(XYZ_Z.Text, CultureInfo.InvariantCulture);
// update other internal values
RGBvalue = XYZvalue.asRGB();
customRGBvalue = XYZvalue.as_customRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSLvalue = RGBvalue.asHSL();
HSVvalue = RGBvalue.asHSV();
LUVvalue = XYZvalue.asLUV(ColorHelper.WP_used);
LABvalue = XYZvalue.asLAB(ColorHelper.WP_used);
break;
case "LUV":
// parse input to internal LUVvalue
LUVvalue.L = float.Parse(LUV_L.Text, CultureInfo.InvariantCulture);
LUVvalue.U = float.Parse(LUV_U.Text, CultureInfo.InvariantCulture);
LUVvalue.V = float.Parse(LUV_V.Text, CultureInfo.InvariantCulture);
// update other internal values
XYZvalue = LUVvalue.asXYZ(ColorHelper.WP_used);
RGBvalue = XYZvalue.asRGB();
customRGBvalue = XYZvalue.as_customRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSLvalue = RGBvalue.asHSL();
HSVvalue = RGBvalue.asHSV();
LABvalue = XYZvalue.asLAB(ColorHelper.WP_used);
break;
case "LAB":
// parse input to internal LABvalue
LABvalue.L = float.Parse(LAB_L.Text, CultureInfo.InvariantCulture);
LABvalue.A = float.Parse(LAB_A.Text, CultureInfo.InvariantCulture);
LABvalue.B = float.Parse(LAB_B.Text, CultureInfo.InvariantCulture);
// update other internal values
XYZvalue = LABvalue.asXYZ(ColorHelper.WP_used);
RGBvalue = XYZvalue.asRGB();
customRGBvalue = XYZvalue.as_customRGB();
sRGBvalue = RGBvalue.as_sRGB();
HSLvalue = RGBvalue.asHSL();
HSVvalue = RGBvalue.asHSV();
LUVvalue = XYZvalue.asLUV(ColorHelper.WP_used);
break;
}
UpdateBoxes();
}
/// <summary>
/// mouse hover ofer the OpenGL Window will be handled here
/// </summary>
/// <author>Markus Strobel</author>
private void glControl_MouseHover(object sender, System.EventArgs e)
{
// Get current mouse position within the glControl
Point mousePos = glControl1.PointToClient(Cursor.Position);
// get x,y relative to an origin in the bottom left
float x = mousePos.X;
float y = glControl1.Height - mousePos.Y;
// normalize to 0..1
x /= glControl1.Width;
y /= glControl1.Height;
if (radioButtonXYZView.Checked)
{
Yxy Yxy = new Yxy(x, y);
hoveredXYZColor = Yxy.asXYZ();
hoveredRGBColor = hoveredXYZColor.asRGB(); //FarbRechner.CIEXYZ_to_RGB(FarbRechner.CIEYxy_to_CIEXYZ(Yxy));
x = (float)Math.Round((double)x, 2);
y = (float)Math.Round((double)y, 2);
// filter negative rgb values
if (!(hoveredRGBColor.R < 0 || hoveredRGBColor.G < 0 || hoveredRGBColor.B < 0))
{
try
{
// normalize
float maxV = Math.Max(hoveredRGBColor.R, Math.Max(hoveredRGBColor.G, hoveredRGBColor.B));
hoveredRGBColor.R /= maxV;
hoveredRGBColor.G /= maxV;
hoveredRGBColor.B /= maxV;
// gamma correction
hoveredRGBColor.R = ColorHelper.Reverse_Gamma_Correction(hoveredRGBColor.R);
hoveredRGBColor.G = ColorHelper.Reverse_Gamma_Correction(hoveredRGBColor.G);
hoveredRGBColor.B = ColorHelper.Reverse_Gamma_Correction(hoveredRGBColor.B);
panelColorPreview.BackColor = Color.FromArgb((int)(hoveredRGBColor.R * 255), (int)(hoveredRGBColor.G * 255), (int)(hoveredRGBColor.B * 255));
labelColorPreviewHex.Text = "#" + ((int)(hoveredRGBColor.R * 255)).ToString("X") + ((int)(hoveredRGBColor.G * 255)).ToString("X") + ((int)(hoveredRGBColor.B * 255)).ToString("X");
}
catch
{
labelColorPreviewHex.Text = "#000";
panelColorPreview.BackColor = Color.Black;
}
}
else
{
labelColorPreviewHex.Text = "#000";
panelColorPreview.BackColor = Color.Black;
}
labelColPreviewXH.Text = "x: " + x.ToString();
labelColPreviewYS.Text = "y: " + y.ToString();
}
}
/// <summary>
/// transformatin CIE XYZ -> CIE L*a*b*
/// source: http://en.wikipedia.org/wiki/CIELUV
/// </summary>
/// <author>Birthe Anne Wiegand</author>
/// <returns>L*u*v* value</returns>
public LUV asLUV(XYZ WP)
{
LUV temp = new LUV();
float XXn = this.X / WP.X; // X / Xn
float YYn = this.Y / WP.Y; // Y / Yn
float ZZn = this.Z / WP.Z; // Z / Zn
if (YYn <= 0.008856452)
{
temp.L = 903.2962963f * YYn;
}
else
{
temp.L = 116f * (float)Math.Pow(YYn, (1f / 3f)) - 16;
}
temp.U = 13f * temp.L * (ColorHelper.function_XYZ_to_LUV(this)[0] - ColorHelper.function_XYZ_to_LUV(WP)[0]);
temp.V = 13f * temp.L * (ColorHelper.function_XYZ_to_LUV(this)[1] - ColorHelper.function_XYZ_to_LUV(WP)[1]);
// to catch the otherwise occuring exception for (input.X + 15f * input.Y + 3f * input.Z) = 0
// (ColorHelper.function_XYZ_to_LUV divides by zero if (input.X + 15f * input.Y + 3f * input.Z) = 0)
// u* and v* are given the value 0 just for interface clarity as there is no information given about them.
// (so 0 is as good as any other value, but does not imply anything wrong)
if (float.IsNaN(temp.U)) temp.U = 0f;
if (float.IsNaN(temp.V)) temp.V = 0f;
return temp;
}
/// <summary>
/// transformatin CIE XYZ -> CIE L*u*v*
/// source: http://www.farbmetrik-gall.de/cielab/index.html, http://en.wikipedia.org/wiki/Lab_color_space
/// </summary>
/// <author>Birthe Anne Wiegand</author>
/// <returns>L*a*b* value</returns>
public LAB asLAB(XYZ WP)
{
LAB temp = new LAB();
float XXn = this.X / WP.X; // X / Xn
float YYn = this.Y / WP.Y; // Y / Yn
float ZZn = this.Z / WP.Z; // Z / Zn
temp.L = 116f * function_XYZ_to_LAB(YYn) - 16f;
temp.A = 500f * (function_XYZ_to_LAB(XXn) - function_XYZ_to_LAB(YYn));
temp.B = 200f * (function_XYZ_to_LAB(YYn) - function_XYZ_to_LAB(ZZn));
return temp;
}
