% Graphic Gems - Graphic Support Methods %
% %
% Software Design %
-% John Cristy %
+% Cristy %
% August 1996 %
% %
% %
-% Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization %
+% Copyright 1999-2014 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
%
% A description of each parameter follows:
%
-% o hue, chroma, luma: A double value representing a
-% component of the HCL color space.
+% o hue, chroma, luma: A double value representing a component of the
+% HCL color space.
%
% o red, green, blue: A pointer to a pixel component of type Quantum.
%
b=0.0;
if ((0.0 <= h) && (h < 1.0))
{
- r=c;
- g=x;
+ r=c;
+ g=x;
}
else
if ((1.0 <= h) && (h < 2.0))
{
- r=x;
- g=c;
+ r=x;
+ g=c;
}
else
if ((2.0 <= h) && (h < 3.0))
{
- g=c;
- b=x;
+ g=c;
+ b=x;
}
else
if ((3.0 <= h) && (h < 4.0))
{
- g=x;
- b=c;
+ g=x;
+ b=c;
}
else
if ((4.0 <= h) && (h < 5.0))
{
- r=x;
- b=c;
+ r=x;
+ b=c;
}
else
if ((5.0 <= h) && (h < 6.0))
{
- r=c;
- b=x;
+ r=c;
+ b=x;
}
- m=luma-0.298839*r+0.586811*g+0.114350*b;
+ m=luma-(0.298839*r+0.586811*g+0.114350*b);
*red=QuantumRange*(r+m);
*green=QuantumRange*(g+m);
*blue=QuantumRange*(b+m);
% %
% %
% %
+% C o n v e r t H C L p T o R G B %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertHCLpToRGB() transforms a (hue, chroma, luma) to a (red, green,
+% blue) triple. Since HCL colorspace is wider than RGB, we instead choose a
+% saturation strategy to project it on the RGB cube.
+%
+% The format of the ConvertHCLpToRGBImage method is:
+%
+% void ConvertHCLpToRGB(const double hue,const double chroma,
+% const double luma,double *red,double *green,double *blue)
+%
+% A description of each parameter follows:
+%
+% o hue, chroma, luma: A double value representing a componenet of the
+% HCLp color space.
+%
+% o red, green, blue: A pointer to a pixel component of type Quantum.
+%
+*/
+MagickPrivate void ConvertHCLpToRGB(const double hue,const double chroma,
+ const double luma,double *red,double *green,double *blue)
+{
+ double
+ b,
+ c,
+ g,
+ h,
+ m,
+ r,
+ x,
+ z;
+
+ /*
+ Convert HCLp to RGB colorspace.
+ */
+ assert(red != (double *) NULL);
+ assert(green != (double *) NULL);
+ assert(blue != (double *) NULL);
+ h=6.0*hue;
+ c=chroma;
+ x=c*(1.0-fabs(fmod(h,2.0)-1.0));
+ r=0.0;
+ g=0.0;
+ b=0.0;
+ if ((0.0 <= h) && (h < 1.0))
+ {
+ r=c;
+ g=x;
+ }
+ else
+ if ((1.0 <= h) && (h < 2.0))
+ {
+ r=x;
+ g=c;
+ }
+ else
+ if ((2.0 <= h) && (h < 3.0))
+ {
+ g=c;
+ b=x;
+ }
+ else
+ if ((3.0 <= h) && (h < 4.0))
+ {
+ g=x;
+ b=c;
+ }
+ else
+ if ((4.0 <= h) && (h < 5.0))
+ {
+ r=x;
+ b=c;
+ }
+ else
+ if ((5.0 <= h) && (h < 6.0))
+ {
+ r=c;
+ b=x;
+ }
+ m=luma-(0.298839*r+0.586811*g+0.114350*b);
+ z=1.0;
+ if (m < 0.0)
+ {
+ z=luma/(luma-m);
+ m=0.0;
+ }
+ else
+ if (m+c > 1.0)
+ {
+ z=(1.0-luma)/(m+c-luma);
+ m=1.0-z*c;
+ }
+ *red=QuantumRange*(z*r+m);
+ *green=QuantumRange*(z*g+m);
+ *blue=QuantumRange*(z*b+m);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
% C o n v e r t H S B T o R G B %
% %
% %
% %
% %
% %
+% C o n v e r t H S I T o R G B %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertHSIToRGB() transforms a (hue, saturation, intensity) to a (red,
+% green, blue) triple.
+%
+% The format of the ConvertHSIToRGBImage method is:
+%
+% void ConvertHSIToRGB(const double hue,const double saturation,
+% const double intensity,double *red,double *green,double *blue)
+%
+% A description of each parameter follows:
+%
+% o hue, saturation, intensity: A double value representing a
+% component of the HSI color space.
+%
+% o red, green, blue: A pointer to a pixel component of type Quantum.
+%
+*/
+MagickPrivate void ConvertHSIToRGB(const double hue,const double saturation,
+ const double intensity,double *red,double *green,double *blue)
+{
+ double
+ b,
+ g,
+ h,
+ r;
+
+ /*
+ Convert HSI to RGB colorspace.
+ */
+ assert(red != (double *) NULL);
+ assert(green != (double *) NULL);
+ assert(blue != (double *) NULL);
+ h=360.0*hue;
+ h-=360.0*floor(h/360.0);
+ if (h < 120.0)
+ {
+ b=intensity*(1.0-saturation);
+ r=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
+ (MagickPI/180.0)));
+ g=3.0*intensity-r-b;
+ }
+ else
+ if (h < 240.0)
+ {
+ h-=120.0;
+ r=intensity*(1.0-saturation);
+ g=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
+ (MagickPI/180.0)));
+ b=3.0*intensity-r-g;
+ }
+ else
+ {
+ h-=240.0;
+ g=intensity*(1.0-saturation);
+ b=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
+ (MagickPI/180.0)));
+ r=3.0*intensity-g-b;
+ }
+ *red=QuantumRange*r;
+ *green=QuantumRange*g;
+ *blue=QuantumRange*b;
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
% C o n v e r t H S L T o R G B %
% %
% %
% o red, green, blue: A pointer to a pixel component of type Quantum.
%
*/
-
-static inline double ConvertHueToRGB(double m1,double m2,double hue)
-{
- if (hue < 0.0)
- hue+=1.0;
- if (hue > 1.0)
- hue-=1.0;
- if ((6.0*hue) < 1.0)
- return(m1+6.0*(m2-m1)*hue);
- if ((2.0*hue) < 1.0)
- return(m2);
- if ((3.0*hue) < 2.0)
- return(m1+6.0*(m2-m1)*(2.0/3.0-hue));
- return(m1);
-}
-
MagickExport void ConvertHSLToRGB(const double hue,const double saturation,
const double lightness,double *red,double *green,double *blue)
{
double
- b,
- g,
- r,
- m1,
- m2;
+ c,
+ h,
+ min,
+ x;
/*
Convert HSL to RGB colorspace.
assert(red != (double *) NULL);
assert(green != (double *) NULL);
assert(blue != (double *) NULL);
- if (saturation == 0)
+ h=hue*360.0;
+ if (lightness <= 0.5)
+ c=2.0*lightness*saturation;
+ else
+ c=(2.0-2.0*lightness)*saturation;
+ min=lightness-0.5*c;
+ h-=360.0*floor(h/360.0);
+ h/=60.0;
+ x=c*(1.0-fabs(h-2.0*floor(h/2.0)-1.0));
+ switch ((int) floor(h))
+ {
+ case 0:
{
- *red=QuantumRange*lightness;
- *green=(*red);
- *blue=(*red);
- return;
+ *red=QuantumRange*(min+c);
+ *green=QuantumRange*(min+x);
+ *blue=QuantumRange*min;
+ break;
}
- if (lightness < 0.5)
- m2=lightness*(saturation+1.0);
- else
- m2=(lightness+saturation)-(lightness*saturation);
- m1=2.0*lightness-m2;
- r=ConvertHueToRGB(m1,m2,hue+1.0/3.0);
- g=ConvertHueToRGB(m1,m2,hue);
- b=ConvertHueToRGB(m1,m2,hue-1.0/3.0);
- *red=QuantumRange*r;
- *green=QuantumRange*g;
- *blue=QuantumRange*b;
+ case 1:
+ {
+ *red=QuantumRange*(min+x);
+ *green=QuantumRange*(min+c);
+ *blue=QuantumRange*min;
+ break;
+ }
+ case 2:
+ {
+ *red=QuantumRange*min;
+ *green=QuantumRange*(min+c);
+ *blue=QuantumRange*(min+x);
+ break;
+ }
+ case 3:
+ {
+ *red=QuantumRange*min;
+ *green=QuantumRange*(min+x);
+ *blue=QuantumRange*(min+c);
+ break;
+ }
+ case 4:
+ {
+ *red=QuantumRange*(min+x);
+ *green=QuantumRange*min;
+ *blue=QuantumRange*(min+c);
+ break;
+ }
+ case 5:
+ {
+ *red=QuantumRange*(min+c);
+ *green=QuantumRange*min;
+ *blue=QuantumRange*(min+x);
+ break;
+ }
+ default:
+ {
+ *red=0.0;
+ *green=0.0;
+ *blue=0.0;
+ }
+ }
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t H S V T o R G B %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertHSVToRGB() transforms a (hue, saturation, value) to a (red,
+% green, blue) triple.
+%
+% The format of the ConvertHSVToRGBImage method is:
+%
+% void ConvertHSVToRGB(const double hue,const double saturation,
+% const double value,double *red,double *green,double *blue)
+%
+% A description of each parameter follows:
+%
+% o hue, saturation, value: A double value representing a
+% component of the HSV color space.
+%
+% o red, green, blue: A pointer to a pixel component of type Quantum.
+%
+*/
+MagickPrivate void ConvertHSVToRGB(const double hue,const double saturation,
+ const double value,double *red,double *green,double *blue)
+{
+ double
+ c,
+ h,
+ min,
+ x;
+
+ /*
+ Convert HSV to RGB colorspace.
+ */
+ assert(red != (double *) NULL);
+ assert(green != (double *) NULL);
+ assert(blue != (double *) NULL);
+ h=hue*360.0;
+ c=value*saturation;
+ min=value-c;
+ h-=360.0*floor(h/360.0);
+ h/=60.0;
+ x=c*(1.0-fabs(h-2.0*floor(h/2.0)-1.0));
+ switch ((int) floor(h))
+ {
+ case 0:
+ {
+ *red=QuantumRange*(min+c);
+ *green=QuantumRange*(min+x);
+ *blue=QuantumRange*min;
+ break;
+ }
+ case 1:
+ {
+ *red=QuantumRange*(min+x);
+ *green=QuantumRange*(min+c);
+ *blue=QuantumRange*min;
+ break;
+ }
+ case 2:
+ {
+ *red=QuantumRange*min;
+ *green=QuantumRange*(min+c);
+ *blue=QuantumRange*(min+x);
+ break;
+ }
+ case 3:
+ {
+ *red=QuantumRange*min;
+ *green=QuantumRange*(min+x);
+ *blue=QuantumRange*(min+c);
+ break;
+ }
+ case 4:
+ {
+ *red=QuantumRange*(min+x);
+ *green=QuantumRange*min;
+ *blue=QuantumRange*(min+c);
+ break;
+ }
+ case 5:
+ {
+ *red=QuantumRange*(min+c);
+ *green=QuantumRange*min;
+ *blue=QuantumRange*(min+x);
+ break;
+ }
+ default:
+ {
+ *red=0.0;
+ *green=0.0;
+ *blue=0.0;
+ }
+ }
}
\f
/*
% %
% %
% %
-% C o n v e r t R G B T o H C L %
+% C o n v e r t L C H a b T o R G B %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-% ConvertRGBToHCL() transforms a (red, green, blue) to a (hue, chroma,
-% luma) triple.
+% ConvertLCHabToRGB() transforms a (luma, chroma, hue) to a (red, green,
+% blue) triple.
%
-% The format of the ConvertRGBToHCL method is:
+% The format of the ConvertLCHabToRGBImage method is:
%
-% void ConvertRGBToHCL(const double red,const double green,
-% const double blue,double *hue,double *chroma,double *luma)
+% void ConvertLCHabToRGB(const double luma,const double chroma,
+% const double hue,double *red,double *green,double *blue)
%
% A description of each parameter follows:
%
-% o red, green, blue: A Quantum value representing the red, green, and
-% blue component of a pixel.
+% o luma, chroma, hue: A double value representing a component of the
+% LCHab color space.
%
-% o hue, chroma, luma: A pointer to a double value representing a
-% component of the HCL color space.
+% o red, green, blue: A pointer to a pixel component of type Quantum.
%
*/
-static inline double MagickMax(const double x,const double y)
-{
- if (x > y)
- return(x);
- return(y);
-}
-
-static inline double MagickMin(const double x,const double y)
+static inline void ConvertLCHabToXYZ(const double luma,const double chroma,
+ const double hue,double *X,double *Y,double *Z)
{
- if (x < y)
- return(x);
- return(y);
+ ConvertLabToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
+ sin(hue*MagickPI/180.0),X,Y,Z);
}
-MagickPrivate void ConvertRGBToHCL(const double red,const double green,
- const double blue,double *hue,double *chroma,double *luma)
+MagickPrivate void ConvertLCHabToRGB(const double luma,const double chroma,
+ const double hue,double *red,double *green,double *blue)
{
double
- b,
- c,
- g,
- h,
- max,
+ X,
+ Y,
+ Z;
+
+ /*
+ Convert LCHab to RGB colorspace.
+ */
+ assert(red != (double *) NULL);
+ assert(green != (double *) NULL);
+ assert(blue != (double *) NULL);
+ ConvertLCHabToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,&X,&Y,&Z);
+ ConvertXYZToRGB(X,Y,Z,red,green,blue);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t L C H u v T o R G B %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertLCHuvToRGB() transforms a (luma, chroma, hue) to a (red, green,
+% blue) triple.
+%
+% The format of the ConvertLCHuvToRGBImage method is:
+%
+% void ConvertLCHuvToRGB(const double luma,const double chroma,
+% const double hue,double *red,double *green,double *blue)
+%
+% A description of each parameter follows:
+%
+% o luma, chroma, hue: A double value representing a component of the
+% LCHuv color space.
+%
+% o red, green, blue: A pointer to a pixel component of type Quantum.
+%
+*/
+
+static inline void ConvertLCHuvToXYZ(const double luma,const double chroma,
+ const double hue,double *X,double *Y,double *Z)
+{
+ ConvertLuvToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
+ sin(hue*MagickPI/180.0),X,Y,Z);
+}
+
+MagickPrivate void ConvertLCHuvToRGB(const double luma,const double chroma,
+ const double hue,double *red,double *green,double *blue)
+{
+ double
+ X,
+ Y,
+ Z;
+
+ /*
+ Convert LCHuv to RGB colorspace.
+ */
+ assert(red != (double *) NULL);
+ assert(green != (double *) NULL);
+ assert(blue != (double *) NULL);
+ ConvertLCHuvToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,&X,&Y,&Z);
+ ConvertXYZToRGB(X,Y,Z,red,green,blue);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t R G B T o H C L %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToHCL() transforms a (red, green, blue) to a (hue, chroma,
+% luma) triple.
+%
+% The format of the ConvertRGBToHCL method is:
+%
+% void ConvertRGBToHCL(const double red,const double green,
+% const double blue,double *hue,double *chroma,double *luma)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel.
+%
+% o hue, chroma, luma: A pointer to a double value representing a
+% component of the HCL color space.
+%
+*/
+
+static inline double MagickMax(const double x,const double y)
+{
+ if (x > y)
+ return(x);
+ return(y);
+}
+
+static inline double MagickMin(const double x,const double y)
+{
+ if (x < y)
+ return(x);
+ return(y);
+}
+
+MagickPrivate void ConvertRGBToHCL(const double red,const double green,
+ const double blue,double *hue,double *chroma,double *luma)
+{
+ double
+ b,
+ c,
+ g,
+ h,
+ max,
r;
/*
max=MagickMax(r,MagickMax(g,b));
c=max-(double) MagickMin(r,MagickMin(g,b));
h=0.0;
- if (c == 0)
+ if (c == 0.0)
h=0.0;
else
if (red == max)
- h=fmod((g-b)/c,6.0);
+ h=fmod((g-b)/c+6.0,6.0);
+ else
+ if (green == max)
+ h=((b-r)/c)+2.0;
+ else
+ if (blue == max)
+ h=((r-g)/c)+4.0;
+ *hue=(h/6.0);
+ *chroma=QuantumScale*c;
+ *luma=QuantumScale*(0.298839*r+0.586811*g+0.114350*b);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t R G B T o H C L p %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToHCLp() transforms a (red, green, blue) to a (hue, chroma,
+% luma) triple.
+%
+% The format of the ConvertRGBToHCLp method is:
+%
+% void ConvertRGBToHCLp(const double red,const double green,
+% const double blue,double *hue,double *chroma,double *luma)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel.
+%
+% o hue, chroma, luma: A pointer to a double value representing a
+% component of the HCL color space.
+%
+*/
+MagickPrivate void ConvertRGBToHCLp(const double red,const double green,
+ const double blue,double *hue,double *chroma,double *luma)
+{
+ double
+ b,
+ c,
+ g,
+ h,
+ max,
+ r;
+
+ /*
+ Convert RGB to HCL colorspace.
+ */
+ assert(hue != (double *) NULL);
+ assert(chroma != (double *) NULL);
+ assert(luma != (double *) NULL);
+ r=red;
+ g=green;
+ b=blue;
+ max=MagickMax(r,MagickMax(g,b));
+ c=max-(double) MagickMin(r,MagickMin(g,b));
+ h=0.0;
+ if (c == 0.0)
+ h=0.0;
+ else
+ if (red == max)
+ h=fmod((g-b)/c+6.0,6.0);
else
if (green == max)
h=((b-r)/c)+2.0;
% %
% %
% %
+% C o n v e r t R G B T o H S I %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToHSI() transforms a (red, green, blue) to a (hue, saturation,
+% intensity) triple.
+%
+% The format of the ConvertRGBToHSI method is:
+%
+% void ConvertRGBToHSI(const double red,const double green,
+% const double blue,double *hue,double *saturation,double *intensity)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel..
+%
+% o hue, saturation, intensity: A pointer to a double value representing a
+% component of the HSI color space.
+%
+*/
+MagickPrivate void ConvertRGBToHSI(const double red,const double green,
+ const double blue,double *hue,double *saturation,double *intensity)
+{
+ double
+ alpha,
+ beta;
+
+ /*
+ Convert RGB to HSI colorspace.
+ */
+ assert(hue != (double *) NULL);
+ assert(saturation != (double *) NULL);
+ assert(intensity != (double *) NULL);
+ *intensity=(QuantumScale*red+QuantumScale*green+QuantumScale*blue)/3.0;
+ if (*intensity <= 0.0)
+ {
+ *hue=0.0;
+ *saturation=0.0;
+ return;
+ }
+ *saturation=1.0-MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
+ QuantumScale*blue))/(*intensity);
+ alpha=0.5*(2.0*QuantumScale*red-QuantumScale*green-QuantumScale*blue);
+ beta=0.8660254037844385*(QuantumScale*green-QuantumScale*blue);
+ *hue=atan2(beta,alpha)*(180.0/MagickPI)/360.0;
+ if (*hue < 0.0)
+ *hue+=1.0;
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
% C o n v e r t R G B T o H S L %
% %
% %
const double blue,double *hue,double *saturation,double *lightness)
{
double
- b,
- delta,
- g,
+ c,
max,
- min,
- r;
+ min;
/*
Convert RGB to HSL colorspace.
assert(hue != (double *) NULL);
assert(saturation != (double *) NULL);
assert(lightness != (double *) NULL);
- r=QuantumScale*red;
- g=QuantumScale*green;
- b=QuantumScale*blue;
- max=MagickMax(r,MagickMax(g,b));
- min=MagickMin(r,MagickMin(g,b));
- *lightness=(double) ((min+max)/2.0);
- delta=max-min;
- if (delta == 0.0)
+ max=MagickMax(QuantumScale*red,MagickMax(QuantumScale*green,
+ QuantumScale*blue));
+ min=MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
+ QuantumScale*blue));
+ c=max-min;
+ *lightness=(max+min)/2.0;
+ if (c <= 0.0)
{
*hue=0.0;
*saturation=0.0;
return;
}
- if (*lightness < 0.5)
- *saturation=(double) (delta/(min+max));
+ if (max == (QuantumScale*red))
+ {
+ *hue=(QuantumScale*green-QuantumScale*blue)/c;
+ if ((QuantumScale*green) < (QuantumScale*blue))
+ *hue+=6.0;
+ }
else
- *saturation=(double) (delta/(2.0-max-min));
- if (r == max)
- *hue=((((max-b)/6.0)+(delta/2.0))-(((max-g)/6.0)+(delta/2.0)))/delta;
+ if (max == (QuantumScale*green))
+ *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
+ else
+ *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
+ *hue*=60.0/360.0;
+ if (*lightness <= 0.5)
+ *saturation=c/(2.0*(*lightness));
else
- if (g == max)
- *hue=(1.0/3.0)+((((max-r)/6.0)+(delta/2.0))-(((max-b)/6.0)+(delta/2.0)))/
- delta;
+ *saturation=c/(2.0-2.0*(*lightness));
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t R G B T o H S V %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToHSV() transforms a (red, green, blue) to a (hue, saturation,
+% value) triple.
+%
+% The format of the ConvertRGBToHSV method is:
+%
+% void ConvertRGBToHSV(const double red,const double green,
+% const double blue,double *hue,double *saturation,double *value)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel..
+%
+% o hue, saturation, value: A pointer to a double value representing a
+% component of the HSV color space.
+%
+*/
+MagickPrivate void ConvertRGBToHSV(const double red,const double green,
+ const double blue,double *hue,double *saturation,double *value)
+{
+ double
+ c,
+ max,
+ min;
+
+ /*
+ Convert RGB to HSV colorspace.
+ */
+ assert(hue != (double *) NULL);
+ assert(saturation != (double *) NULL);
+ assert(value != (double *) NULL);
+ max=MagickMax(QuantumScale*red,MagickMax(QuantumScale*green,
+ QuantumScale*blue));
+ min=MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
+ QuantumScale*blue));
+ c=max-min;
+ *value=max;
+ if (c <= 0.0)
+ {
+ *hue=0.0;
+ *saturation=0.0;
+ return;
+ }
+ if (max == (QuantumScale*red))
+ {
+ *hue=(QuantumScale*green-QuantumScale*blue)/c;
+ if ((QuantumScale*green) < (QuantumScale*blue))
+ *hue+=6.0;
+ }
+ else
+ if (max == (QuantumScale*green))
+ *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
else
- if (b == max)
- *hue=(2.0/3.0)+((((max-g)/6.0)+(delta/2.0))-(((max-r)/6.0)+
- (delta/2.0)))/delta;
- if (*hue < 0.0)
- *hue+=1.0;
- if (*hue > 1.0)
- *hue-=1.0;
+ *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
+ *hue*=60.0/360.0;
+ *saturation=c/max;
}
\f
/*
% %
% %
% %
+% C o n v e r t R G B T o L C H a b %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToLCHab() transforms a (red, green, blue) to a (luma, chroma,
+% hue) triple.
+%
+% The format of the ConvertRGBToLCHab method is:
+%
+% void ConvertRGBToLCHab(const double red,const double green,
+% const double blue,double *luma,double *chroma,double *hue)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel.
+%
+% o luma, chroma, hue: A pointer to a double value representing a
+% component of the LCH color space.
+%
+*/
+
+static inline void ConvertXYZToLCHab(const double X,const double Y,
+ const double Z,double *luma,double *chroma,double *hue)
+{
+ double
+ a,
+ b;
+
+ ConvertXYZToLab(X,Y,Z,luma,&a,&b);
+ *chroma=hypot(255.0*(a-0.5),255.0*(b-0.5))/255.0+0.5;
+ *hue=180.0*atan2(255.0*(b-0.5),255.0*(a-0.5))/MagickPI/360.0;
+ if (*hue < 0.0)
+ *hue+=1.0;
+}
+
+MagickPrivate void ConvertRGBToLCHab(const double red,const double green,
+ const double blue,double *luma,double *chroma,double *hue)
+{
+ double
+ X,
+ Y,
+ Z;
+
+ /*
+ Convert RGB to LCHab colorspace.
+ */
+ assert(luma != (double *) NULL);
+ assert(chroma != (double *) NULL);
+ assert(hue != (double *) NULL);
+ ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
+ ConvertXYZToLCHab(X,Y,Z,luma,chroma,hue);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
+% C o n v e r t R G B T o L C H u v %
+% %
+% %
+% %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% ConvertRGBToLCHuv() transforms a (red, green, blue) to a (luma, chroma,
+% hue) triple.
+%
+% The format of the ConvertRGBToLCHuv method is:
+%
+% void ConvertRGBToLCHuv(const double red,const double green,
+% const double blue,double *luma,double *chroma,double *hue)
+%
+% A description of each parameter follows:
+%
+% o red, green, blue: A Quantum value representing the red, green, and
+% blue component of a pixel.
+%
+% o luma, chroma, hue: A pointer to a double value representing a
+% component of the LCHuv color space.
+%
+*/
+
+static inline void ConvertXYZToLCHuv(const double X,const double Y,
+ const double Z,double *luma,double *chroma,double *hue)
+{
+ double
+ u,
+ v;
+
+ ConvertXYZToLuv(X,Y,Z,luma,&u,&v);
+ *chroma=hypot(354.0*u-134.0,262.0*v-140.0)/255.0+0.5;
+ *hue=180.0*atan2(262.0*v-140.0,354.0*u-134.0)/MagickPI/360.0;
+ if (*hue < 0.0)
+ *hue+=1.0;
+}
+
+MagickPrivate void ConvertRGBToLCHuv(const double red,const double green,
+ const double blue,double *luma,double *chroma,double *hue)
+{
+ double
+ X,
+ Y,
+ Z;
+
+ /*
+ Convert RGB to LCHuv colorspace.
+ */
+ assert(luma != (double *) NULL);
+ assert(chroma != (double *) NULL);
+ assert(hue != (double *) NULL);
+ ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
+ ConvertXYZToLCHuv(X,Y,Z,luma,chroma,hue);
+}
+\f
+/*
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %
+% %
+% %
% E x p a n d A f f i n e %
% %
% %
%
% A description of each parameter follows:
%
-% o expansion: Method ExpandAffine returns the affine's expansion factor.
+% o expansion: ExpandAffine returns the affine's expansion factor.
%
% o affine: A pointer the affine transform of type AffineMatrix.
%
%
% A description of each parameter follows:
%
-% o width: Method GetOptimalKernelWidth returns the optimal width of
-% a convolution kernel.
+% o width: GetOptimalKernelWidth returns the optimal width of a
+% convolution kernel.
%
% o radius: the radius of the Gaussian, in pixels, not counting the center
% pixel.
gamma=fabs(sigma);
if (gamma <= MagickEpsilon)
return(3UL);
- alpha=MagickEpsilonReciprocal(2.0*gamma*gamma);
- beta=(double) MagickEpsilonReciprocal((double) MagickSQ2PI*gamma);
+ alpha=PerceptibleReciprocal(2.0*gamma*gamma);
+ beta=(double) PerceptibleReciprocal((double) MagickSQ2PI*gamma);
for (width=5; ; )
{
normalize=0.0;
- j=(ssize_t) width/2;
+ j=(ssize_t) (width-1)/2;
for (i=(-j); i <= j; i++)
normalize+=exp(-((double) (i*i))*alpha)*beta;
value=exp(-((double) (j*j))*alpha)*beta/normalize;
gamma=fabs(sigma);
if (gamma <= MagickEpsilon)
return(3UL);
- alpha=MagickEpsilonReciprocal(2.0*gamma*gamma);
- beta=(double) MagickEpsilonReciprocal((double) Magick2PI*gamma*gamma);
+ alpha=PerceptibleReciprocal(2.0*gamma*gamma);
+ beta=(double) PerceptibleReciprocal((double) Magick2PI*gamma*gamma);
for (width=5; ; )
{
normalize=0.0;
- j=(ssize_t) width/2;
+ j=(ssize_t) (width-1)/2;
for (v=(-j); v <= j; v++)
for (u=(-j); u <= j; u++)
normalize+=exp(-((double) (u*u+v*v))*alpha)*beta;
projects / imagemagick / blobdiff