/// <summary>
/// foamliu, 2009/02/03, 累积灰度直方图.
///
/// </summary>
/// <param name="bmp"></param>
/// <returns></returns>
public static double[] CumulativeHistogram(Bitmap bmp)
{
int width, height;
int[][] mat;
ImageConvert.Bitmap2Mat(bmp, out mat, out width, out height);
double[] cumuHist = GrayScaleImageLib.CumulativeHistogram(mat);
return(cumuHist);
}
/// <summary>
/// foamliu, 2009/02/03, 鲁棒的(这个词好怪 -_-!!)正则化.
/// 比如 pl=0.1, pu=0.99.
///
/// </summary>
/// <param name="mat"></param>
public static void RobustNormalize(int[][] mat, double pl, double pu)
{
int width = mat.Length;
int height = mat[0].Length;
// 第一遍， 取得最大最小值.
int min = 0, max = 255;
double[] cumuHist = GrayScaleImageLib.CumulativeHistogram(mat);
for (int i = 0; i < 256; i++)
{
if (cumuHist[i] > pl)
{
min = i - 1;
break;
}
}
for (int i = 255; i >= 0; i--)
{
if (cumuHist[i] < pu)
{
max = i + 1;
break;
}
}
// 第二遍，归一化.
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
int grayScale = mat[x][y];
if (grayScale > max)
{
grayScale = max;
}
if (grayScale < min)
{
grayScale = min;
}
mat[x][y] = 255 * (grayScale - min) / (max - min);
}
}
}
