//-------------------------------------------------------------------------
#endregion
#region private Method
//-------------------------------------------------------------------------
/// <summary>
/// 这段代码？切分矩阵
/// </summary>
/// <param name="partialsum"></param>
/// <param name="lookaheadsum"></param>
/// <param name="vbox"></param>
/// <param name="color"></param>
/// <param name="total"></param>
/// <returns></returns>
private static EICBox[] __DoCut(Dictionary <int, int?> partialsum,
Dictionary <int, int?> lookaheadsum,
EICBox vbox, string color, int total)
{
int i,
left, right, d2;
EICBox vbox1, vbox2;
//从一个维度的最小值到最大值，rgb。
for (i = vbox[color][0]; i <= vbox[color][1]; i++)
{
//代表里面的命中的像素以及大于整体的一半信息。
if (partialsum[i] > total / 2)
{
vbox1 = vbox.copy();
vbox2 = vbox.copy();
left = i - vbox[color][0];
right = vbox[color][1] - i;
if (left <= right)
{
d2 = Math.Min(vbox[color][1] - 1, ~~(i + right / 2));
}
else
{
d2 = Math.Max(vbox[color][0], ~~(i - 1 - left / 2));
}
while (!partialsum[d2].HasValue)
{
d2++;
}
//肯定有内容
var count2 = lookaheadsum[d2];
while (
(!count2.HasValue || count2.Value == 0) &&
partialsum.ContainsKey(d2 - 1) &&
partialsum[d2 - 1].HasValue &&
partialsum[d2 - 1].Value > 0)
{
count2 = lookaheadsum[--d2];
}
// set dimensions
vbox1[color] = new int[] { vbox1[color][0], d2 };
vbox2[color] = new int[] { d2 + 1, vbox2[color][1] };
return(new EICBox[] { vbox1, vbox2 });
}
}
return(null);
}
//-------------------------------------------------------------------------
private static object[] __MedianCutApply(int[] histo, EICBox vbox)
{
if (vbox.count() == 0)
{
return(null);
}
int rw = vbox.r2 - vbox.r1 + 1,
gw = vbox.g2 - vbox.g1 + 1,
bw = vbox.b2 - vbox.b1 + 1,
//最大颜色，按照最大的变进行切分
maxw = Math.Max(Math.Max(rw, gw), bw);
// only one pixel, no split
if (vbox.count() == 1)
{
return(new EICBox[] { vbox.copy(), null });
}
/* Find the partial sum arrays along the selected axis. */
int total = 0;
Dictionary <int, int?> partialsum = new Dictionary <int, int?>();
Dictionary <int, int?> lookaheadsum = new Dictionary <int, int?>();
int i, j, k, sum, index;
if (maxw == rw)
{
for (i = vbox.r1; i <= vbox.r2; i++)
{
sum = 0;
for (j = vbox.g1; j <= vbox.g2; j++)
{
for (k = vbox.b1; k <= vbox.b2; k++)
{
index = GetColorIndex(i, j, k);
sum += index < histo.Length ? histo[index] : 0;
}
}
total += sum;
partialsum[i] = total;
}
}
else if (maxw == gw)
{
for (i = vbox.g1; i <= vbox.g2; i++)
{
sum = 0;
for (j = vbox.r1; j <= vbox.r2; j++)
{
for (k = vbox.b1; k <= vbox.b2; k++)
{
index = GetColorIndex(j, i, k);
sum += index < histo.Length ? histo[index] : 0;
}
}
total += sum;
partialsum[i] = total;
}
}
else
{ /* maxw == bw */
for (i = vbox.b1; i <= vbox.b2; i++)
{
sum = 0;
for (j = vbox.r1; j <= vbox.r2; j++)
{
for (k = vbox.g1; k <= vbox.g2; k++)
{
index = GetColorIndex(j, k, i);
sum += index < histo.Length ? histo[index] : 0;
}
}
total += sum;
partialsum[i] = total;
}
}
foreach (var v in partialsum)
{
//计算剩余的部分
lookaheadsum[v.Key] = total - v.Value;
}
// determine the cut planes
return
(maxw == rw?__DoCut(partialsum, lookaheadsum, vbox, "r", total) :
maxw == gw?__DoCut(partialsum, lookaheadsum, vbox, "g", total) :
__DoCut(partialsum, lookaheadsum, vbox, "b", total));
}