光の周波数を RGB 値に変換する公式を知っている人はいますか?
ベストアンサー1
怠け者(私のような)のために、@user151323の回答にあるコードのJavaでの実装を示します(つまり、スペクトララボレポート):
static private final double Gamma = 0.80;
static private final double IntensityMax = 255;
/**
* Taken from Earl F. Glynn's web page:
* <a href="http://www.efg2.com/Lab/ScienceAndEngineering/Spectra.htm">Spectra Lab Report</a>
*/
public static int[] waveLengthToRGB(double Wavelength) {
double factor;
double Red, Green, Blue;
if((Wavelength >= 380) && (Wavelength < 440)) {
Red = -(Wavelength - 440) / (440 - 380);
Green = 0.0;
Blue = 1.0;
} else if((Wavelength >= 440) && (Wavelength < 490)) {
Red = 0.0;
Green = (Wavelength - 440) / (490 - 440);
Blue = 1.0;
} else if((Wavelength >= 490) && (Wavelength < 510)) {
Red = 0.0;
Green = 1.0;
Blue = -(Wavelength - 510) / (510 - 490);
} else if((Wavelength >= 510) && (Wavelength < 580)) {
Red = (Wavelength - 510) / (580 - 510);
Green = 1.0;
Blue = 0.0;
} else if((Wavelength >= 580) && (Wavelength < 645)) {
Red = 1.0;
Green = -(Wavelength - 645) / (645 - 580);
Blue = 0.0;
} else if((Wavelength >= 645) && (Wavelength < 781)) {
Red = 1.0;
Green = 0.0;
Blue = 0.0;
} else {
Red = 0.0;
Green = 0.0;
Blue = 0.0;
}
// Let the intensity fall off near the vision limits
if((Wavelength >= 380) && (Wavelength < 420)) {
factor = 0.3 + 0.7 * (Wavelength - 380) / (420 - 380);
} else if((Wavelength >= 420) && (Wavelength < 701)) {
factor = 1.0;
} else if((Wavelength >= 701) && (Wavelength < 781)) {
factor = 0.3 + 0.7 * (780 - Wavelength) / (780 - 700);
} else {
factor = 0.0;
}
int[] rgb = new int[3];
// Don't want 0^x = 1 for x <> 0
rgb[0] = Red == 0.0 ? 0 : (int)Math.round(IntensityMax * Math.pow(Red * factor, Gamma));
rgb[1] = Green == 0.0 ? 0 : (int)Math.round(IntensityMax * Math.pow(Green * factor, Gamma));
rgb[2] = Blue == 0.0 ? 0 : (int)Math.round(IntensityMax * Math.pow(Blue * factor, Gamma));
return rgb;
}