直方图匹配的代码如下：
//直方图匹配（规定）将原图像按照给定直方图匹配，这个函数中给定的直方图图片形式，第二个参数为给定的直方图
static public
Image<Gray, Byte> histogrammatching(Image<Gray, Byte>
input,Image<Gray,Byte> MachingImage)
{
var
result = input.CopyBlank();
int[] srcgraylevel = new int[256];
int[]
dstgraylevel = new int[256];
byte[] newgray = new byte[256];
//求原图像上每个灰度级上的像素个数，结果存储在srcgraylevel数组中
for (int i = 0; i
< input.Width; i++)
{
for (int j = 0; j
< input.Height; j++)
{
srcgraylevel[input.Data[j, i, 0]]++;
}
}
//求匹配图像上每个灰度级上的像素个数，结果存储到dstgraylevel数组中
for (int i = 0; i
< MachingImage.Width; i++)
{
for (int j =
0; j < MachingImage.Height; j++)
{
dstgraylevel[MachingImage.Data[j, i, 0]]++;
}
}
int srcsum=0;//原图像像素累积分布
for (int i = 0; i <= 255; i++)
{
int dstsum=0;//匹配图像像素的累积分布
int
graydifference1=int.MaxValue,graydifference2=0;//记录两个图像中像素累积分布的差值
newgray[i]
= 0;
if (srcgraylevel[i] > 0)
{
srcsum = srcsum + srcgraylevel[i];
int lastgraylevel = 0;
for (int j
= 0; j <= 255; j++)
{
if (dstgraylevel[j] > 0)
{
dstsum = dstsum + dstgraylevel[j];
graydifference2 = dstsum - srcsum;
graydifference2 = Math.Abs(graydifference2);
if (graydifference2 <= graydifference1)
{
graydifference1 = graydifference2;
lastgraylevel=j;
}
else
{
newgray[i] = (byte)(lastgraylevel);
break;
}
}
}
}
}
//将原图像中的每个点替换成新的灰度,得到直方图规定化的结果
for (int i = 0; i <
input.Width; i++)
{
for (int j = 0; j <
input.Height; j++)
{
result.Data[j, i, 0] = newgray[input.Data[j, i, 0]];
}
}
return result;
}
}
}