private static float computeHistogramRatio(float[] histogramM, float[] histogramI, float[] ratio) { float sum = 0; for (int i = 0; i < ratio.Length; i++) { sum += ratio[i] = (histogramI[i] != 0) ? Math.Max(Math.Min(histogramM[i] / histogramI[i], 1f), 0f) : 0f; } return sum; }