public static Func <byte, byte, byte, Pixel> Equalize(PNM pnm)
{
double[] rawDataR = pnm.GetHistogramRed();
double[] rawDataG = pnm.GetHistogramGreen();
double[] rawDataB = pnm.GetHistogramBlue();
double[] rlum = new double[256];
double[] glum = new double[256];
double[] blum = new double[256];
double cumulatedR = 0;
double cumulatedG = 0;
double cumulatedB = 0;
for (int i = 0; i < 256; i++)
{
cumulatedR += rawDataR[i];
cumulatedG += rawDataG[i];
cumulatedB += rawDataB[i];
rlum[i] = cumulatedR;
glum[i] = cumulatedG;
blum[i] = cumulatedB;
}
return((r, g, b) =>
{
return new Pixel(Convert.ToByte(rlum[r] * 255), Convert.ToByte(glum[g] * 255), Convert.ToByte(blum[b] * 255));
});
}
public static Func<byte, byte, byte, Pixel> Equalize(PNM pnm)
{
double[] rawDataR = pnm.GetHistogramRed();
double[] rawDataG = pnm.GetHistogramGreen();
double[] rawDataB = pnm.GetHistogramBlue();
double[] rlum = new double[256];
double[] glum = new double[256];
double[] blum = new double[256];
double cumulatedR = 0;
double cumulatedG = 0;
double cumulatedB = 0;
for (int i = 0; i < 256; i++)
{
cumulatedR += rawDataR[i];
cumulatedG += rawDataG[i];
cumulatedB += rawDataB[i];
rlum[i] = cumulatedR;
glum[i] = cumulatedG;
blum[i] = cumulatedB;
}
return (r, g, b) =>
{
return new Pixel(Convert.ToByte(rlum[r] * 255), Convert.ToByte(glum[g] * 255), Convert.ToByte(blum[b] * 255));
};
}
public static Func<byte, byte, byte, Pixel> Stretch(PNM pnm)
{
double[] histogramR = pnm.GetHistogramRed();
double[] histogramG = pnm.GetHistogramGreen();
double[] histogramB = pnm.GetHistogramBlue();
double[] cumulativeR = CumulativeHistogram(histogramR);
double[] cumulativeG = CumulativeHistogram(histogramG);
double[] cumulativeB = CumulativeHistogram(histogramB);
Tuple<int, int> rangeR = FindPercentiles(cumulativeR);
Tuple<int, int> rangeG = FindPercentiles(cumulativeG);
Tuple<int, int> rangeB = FindPercentiles(cumulativeB);
int[] LUTR = GetStretchLUT(histogramR, rangeR.Item1, rangeR.Item2);
int[] LUTG = GetStretchLUT(histogramG, rangeG.Item1, rangeG.Item2);
int[] LUTB = GetStretchLUT(histogramB, rangeB.Item1, rangeB.Item2);
return (r, g, b) =>
{
return new Pixel(Convert.ToByte(LUTR[r]), Convert.ToByte(LUTG[g]), Convert.ToByte(LUTB[b]));
};
}
public static Func <byte, byte, byte, Pixel> Stretch(PNM pnm)
{
double[] histogramR = pnm.GetHistogramRed();
double[] histogramG = pnm.GetHistogramGreen();
double[] histogramB = pnm.GetHistogramBlue();
double[] cumulativeR = CumulativeHistogram(histogramR);
double[] cumulativeG = CumulativeHistogram(histogramG);
double[] cumulativeB = CumulativeHistogram(histogramB);
Tuple <int, int> rangeR = FindPercentiles(cumulativeR);
Tuple <int, int> rangeG = FindPercentiles(cumulativeG);
Tuple <int, int> rangeB = FindPercentiles(cumulativeB);
int[] LUTR = GetStretchLUT(histogramR, rangeR.Item1, rangeR.Item2);
int[] LUTG = GetStretchLUT(histogramG, rangeG.Item1, rangeG.Item2);
int[] LUTB = GetStretchLUT(histogramB, rangeB.Item1, rangeB.Item2);
return((r, g, b) =>
{
return new Pixel(Convert.ToByte(LUTR[r]), Convert.ToByte(LUTG[g]), Convert.ToByte(LUTB[b]));
});
}
