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details Polar Color Coordinates
Color Space Conversions
 VIGRA

Functions

template<class V >
TinyVector< float, 3 > lab2Polar (V const &lab)
 Create polar representation form L*a*b*. More...
 
template<class V >
TinyVector< float, 3 > luv2Polar (V const &luv)
 Create polar representation form L*u*v*. More...
 
TinyVector< float, 3 > polar2Lab (double color, double brightness, double saturation)
 Init L*a*b* color triple from polar representation. More...
 
TinyVector< float, 3 > polar2Luv (double color, double brightness, double saturation)
 Init L*u*v* color triple from polar representation. More...
 
TinyVector< float, 3 > polar2YPrimeCbCr (double color, double brightness, double saturation)
 Init Y'CbCr color triple from polar representation. More...
 
TinyVector< float, 3 > polar2YPrimeIQ (double color, double brightness, double saturation)
 Init Y'IQ color triple from polar representation. More...
 
TinyVector< float, 3 > polar2YPrimePbPr (double color, double brightness, double saturation)
 Init Y'PbPr color triple from polar representation. More...
 
TinyVector< float, 3 > polar2YPrimeUV (double color, double brightness, double saturation)
 Init Y'UV color triple from polar representation. More...
 
template<class V >
TinyVector< float, 3 > yPrimeCbCr2Polar (V const &ycbcr)
 Create polar representation form Y'CbCr. More...
 
template<class V >
TinyVector< float, 3 > yPrimeIQ2Polar (V const &yiq)
 Create polar representation form Y'IQ. More...
 
template<class V >
TinyVector< float, 3 > yPrimePbPr2Polar (V const &ypbpr)
 Create polar representation form Y'PbPr. More...
 
template<class V >
TinyVector< float, 3 > yPrimeUV2Polar (V const &yuv)
 Create polar representation form Y'UV. More...
 

Detailed Description

Transform colors from/to a polar representation (hue, brightness, saturation). In many situations, this is more intuitive than direct initialization in a particular color space. The polar coordinates are normalized so that a color angle of 0 degrees is always associated with red (green is at about 120 degrees, blue at about 240 degrees - exact values differ between color spaces). A saturation of 1 is the highest saturation that any RGB color gets after transformation into the respective color space, and saturation 0 corresponds to gray. Thus, different color spaces become somewhat comparable.

Function Documentation

TinyVector<float, 3> vigra::polar2Lab ( double  color,
double  brightness,
double  saturation 
)

Init L*a*b* color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2Lab(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2Lab(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

L*a*b* polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.532406, 0.781353]
yellow = [62.8531, 0.971395, 0.724189]
green = [96.0184, 0.877351, 0.895108]
cyan = [156.378, 0.911133, 0.374577]
blue = [266.287, 0.322957, 0.999997]
magenta = [288.237, 0.603235, 0.863482]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::lab2Polar ( V const &  lab)

Create polar representation form L*a*b*.

Declaration:

namespace vigra {
TinyVector<float, 3> lab2Polar(TinyVector<float, 3> const & lab);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2Lab().

TinyVector<float, 3> vigra::polar2Luv ( double  color,
double  brightness,
double  saturation 
)

Init L*u*v* color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2Luv(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2Luv(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

L*u*v* polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.532406, 1]
yellow = [ 73.7, 0.971395, 0.597953]
green = [115.552, 0.877351, 0.758352]
cyan = [ 180.0, 0.911133, 0.402694]
blue = [ 253.7, 0.322957, 0.729883]
magenta = [295.553, 0.603235, 0.767457]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::luv2Polar ( V const &  luv)

Create polar representation form L*u*v*.

Declaration:

namespace vigra {
TinyVector<float, 3> luv2Polar(TinyVector<float, 3> const & luv);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2Luv().

TinyVector<float, 3> vigra::polar2YPrimePbPr ( double  color,
double  brightness,
double  saturation 
)

Init Y'PbPr color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2YPrimePbPr(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2YPrimePbPr(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

Y'PbPr polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.299, 0.988419]
yellow = [62.1151, 0.886, 0.948831]
green = [123.001, 0.587, 1]
cyan = [ 180.0, 0.701, 0.988419]
blue = [242.115, 0.114, 0.948831]
magenta = [303.001, 0.413, 1]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::yPrimePbPr2Polar ( V const &  ypbpr)

Create polar representation form Y'PbPr.

Declaration:

namespace vigra {
TinyVector<float, 3> yPrimePbPr2Polar(TinyVector<float, 3> const & ypbpr);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2YPrimePbPr().

TinyVector<float, 3> vigra::polar2YPrimeCbCr ( double  color,
double  brightness,
double  saturation 
)

Init Y'CbCr color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2YPrimeCbCr(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2YPrimeCbCr(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

Y'CbCr polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.299, 0.988419]
yellow = [62.1151, 0.886, 0.948831]
green = [123.001, 0.587, 1]
cyan = [ 180.0, 0.701, 0.988419]
blue = [242.115, 0.114, 0.948831]
magenta = [303.001, 0.413, 1]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::yPrimeCbCr2Polar ( V const &  ycbcr)

Create polar representation form Y'CbCr.

Declaration:

namespace vigra {
TinyVector<float, 3> yPrimeCbCr2Polar(TinyVector<float, 3> const & ycbcr);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2YPrimeCbCr().

TinyVector<float, 3> vigra::polar2YPrimeIQ ( double  color,
double  brightness,
double  saturation 
)

Init Y'IQ color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2YPrimeIQ(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2YPrimeIQ(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

Y'IQ polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.299, 1]
yellow = [63.5851, 0.886, 0.707681]
green = [137.231, 0.587, 0.933362]
cyan = [ 180.0, 0.701, 1]
blue = [243.585, 0.114, 0.707681]
magenta = [317.231, 0.413, 0.933362]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::yPrimeIQ2Polar ( V const &  yiq)

Create polar representation form Y'IQ.

Declaration:

namespace vigra {
TinyVector<float, 3> yPrimeIQ2Polar(TinyVector<float, 3> const & yiq);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2YPrimeIQ().

TinyVector<float, 3> vigra::polar2YPrimeUV ( double  color,
double  brightness,
double  saturation 
)

Init Y'UV color triple from polar representation.

#include <vigra/colorconversions.hxx>
Namespace: vigra

Declarations:

TinyVector<float, 3>
polar2YPrimeUV(double color, double brightness, double saturation);
TinyVector<float, 3>
polar2YPrimeUV(TinyVector<float, 3> const & polar);
  • color - the color angle in degrees
  • brightness - between 0 and 1
  • saturation - between 0 and 1

Y'UV polar coordinates of some important colors:

black = [*, 0, 0] * - arbitrary
white = [*, 1, 0] * - arbitrary
red = [ 0, 0.299, 1]
yellow = [63.5851, 0.886, 0.707681]
green = [137.231, 0.587, 0.933362]
cyan = [ 180.0, 0.701, 1]
blue = [243.585, 0.114, 0.707681]
magenta = [317.231, 0.413, 0.933362]
Examples:
palette.cxx.
TinyVector<float, 3> vigra::yPrimeUV2Polar ( V const &  yuv)

Create polar representation form Y'UV.

Declaration:

namespace vigra {
TinyVector<float, 3> yPrimeUV2Polar(TinyVector<float, 3> const & yuv);
}

#include <vigra/colorconversions.hxx>
Namespace: vigra

This realizes the inverse of the transformation described in polar2YPrimeUV().

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de)
Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany

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vigra 1.11.1 (Fri May 19 2017)