Magick::Color

Color is the base color class in Magick++. It is a simple container class for the raw red, green, and blue values scaled to a depth of 16 bits. Normally users will instantiate a class derived from Color which supports the color model that fits the needs of the application. The Color class may be constructed directly from an X11-style color string.

Available derived color specification classes are shown in the following table:
 
Color Derived Classes
ColorRGB Representation of RGB color with red, green, and blue specified as ratios (0 to 1)
ColorGray Representation of grayscale RGB color (equal parts red, green, and blue) specified as a ratio (0 to 1)
ColorMono Representation of a black/white color (true/false)
ColorYUV Representation of a color in the YUV colorspace

 

Base color class stores RGB components scaled to fit ColorType (16 bits)

Color Class

The Color base class is not intended to be used directly. Normally a user will construct a derived class or inherit from this class. Color arguments must be scaled to the ColorType size (16 bits). The ScaleDoubleToQuantum and ScaleQuantumToDouble macros can aid with this task.

An alternate way to contruct the class is via an X11-compatable color specification string.

class Color
{
  friend class Image;
public:
  Color ( ColorType red_, ColorType green_, ColorType blue_ );
  Color ( const std::string x11color_ );
  Color ( const char * x11color_ );
  Color ( void );
  virtual        ~Color ( void );

  // Does object contain valid color?
  void           isValid ( bool valid_ );
  bool           isValid ( void ) const;

  // Set color via X11 color specification string
  const Color& operator = ( std::string x11color_ );
  const Color& operator = ( const char * x11color_ );

  // Return X11 color specification string
  /* virtual */ operator std::string() const;

protected:

  void           redQuantum ( ColorType red_ );
  ColorType      redQuantum ( void ) const;

  void           greenQuantum ( ColorType green_ );
  ColorType      greenQuantum ( void ) const;

  void           blueQuantum ( ColorType blue_ );
  ColorType      blueQuantum ( void ) const;

};
 

ColorRGB

Representation of an RGB color. All color arguments have a valid range of 0.0 - 1.0.

class ColorRGB : public Color
{
public:
  ColorRGB ( double red_, double green_, double blue_ );
  ColorRGB ( const string x11color_ );
  ColorRGB ( void );
  /* virtual */  ~ColorRGB ( void );

  void           red ( double red_ );
  double         red ( void ) const;

  void           green ( double green_ );
  double         green ( void ) const;

  void           blue ( double blue_ );
  double         blue ( void ) const;
};
 

ColorGray

Representation of a grayscale color (in RGB colorspace). Grayscale is simply RGB with equal parts of red, green, and blue. All double arguments have a valid range of 0.0 - 1.0.

class ColorGray : public Color
{
public:
  ColorGray ( double shade_ );
  ColorGray ( void );
  /* virtual */ ~ColorGray ();

  void           shade ( double shade_ );
  double         shade ( void ) const;
};
 

ColorMono

Representation of a black/white pixel (in RGB colorspace). Color arguments are constrained to 'false' (black pixel) and 'true' (white pixel).

class ColorMono : public Color
{
public:
  ColorMono ( bool mono_ );
  ColorMono ( void );
  /* virtual */ ~ColorMono ();

  void           mono ( bool mono_ );
  bool           mono ( void ) const;

};
 

ColorHSL

Representation of a color in Hue/Saturation/Luminosity (HSL) colorspace.

class ColorHSL : public Color
{
public:
  ColorHSL ( double hue_, double saturation_, double luminosity_ );
  ColorHSL ( );
  /* virtual */  ~ColorHSL ( );

  void           hue ( double hue_ );
  double         hue ( void ) const;

  void           saturation ( double saturation_ );
  double         saturation ( void ) const;

  void           luminosity ( double luminosity_ );
  double         luminosity ( void ) const;
};
 

ColorYUV

Representation of a color in YUV colorspace (used to encode color for television transmission).

 Argument ranges:
        Y:  0.0 through 1.0
        U: -0.5 through 0.5
        V: -0.5 through 0.5

class ColorYUV : public Color
{
public:
  ColorYUV ( double y_, double u_, double v_ );
  ColorYUV ( void );
  /* virtual */ ~ColorYUV ( void );

  void           u ( double u_ );
  double         u ( void ) const;

  void           v ( double v_ );
  double         v ( void ) const;

  void           y ( double y_ );
  double         y ( void ) const;
};