/// <summary>
/// Buid an Histogram for a bitmap
/// </summary>
/// <param name="bmp">The bitmap to be analyzed</param>
/// <returns>an array of float containing the frequency found for each luminance</returns>
internal static float[] getFHistogram(Bitmap bmp)
{
float[] hist = new float[256];
if (bmp != null && bmp.Width * bmp.Height != 0)
{
for (int i = 0; i < bmp.Width; i++)
{
for (int j = 0; j < bmp.Height; j++)
{
int lum = IPUtil.RGB2Yint(bmp.GetPixel(i, j));
hist[lum] += 1.0f;
}
}
float nbp = bmp.Width * bmp.Height;
for (int j = 0; j < hist.Length; j++)
{
hist[j] /= nbp;
}
}
return(hist);
}
/// <summary>
/// Retrieve the histogram of 2 Bitmap
/// </summary>
/// <param name="bmp1">the first bitmap</param>
/// <param name="bmp2">the second bitmap</param>
/// <returns>the bihistogram of the bitmap</returns>
internal static float[,] getFBiHistogram(Bitmap bmp1, Bitmap bmp2)
{
float[,] hist = new float[256, 256];
if (bmp1 != null && bmp1.Width * bmp1.Height != 0)
{
if (bmp2 != null && bmp2.Width * bmp2.Height != 0)
{
if (bmp1.Width == bmp2.Width && bmp1.Height == bmp2.Height)
{
int wi = bmp1.Width;
int he = bmp1.Height;
for (int i = 0; i < wi; i++)
{
for (int j = 0; j < he; j++)
{
int lum1 = IPUtil.RGB2Yint(bmp1.GetPixel(i, j));
int lum2 = IPUtil.RGB2Yint(bmp2.GetPixel(i, j));
hist[lum1, lum2] += 1.0f;
}
}
float nbp = wi * he;
nbp *= nbp;
int w = hist.GetUpperBound(0);
int h = hist.GetUpperBound(1);
for (int i = 0; i < w; i++)
{
for (int j = 0; j < h; j++)
{
hist[i, j] /= nbp;
}
}
}
}
}
return(hist);
}