简单图像填充算法
填充算法
递归
private void fillsearch(Bitmap bmp, int x, int y, byte[,] flag,int num)
{
//向左 如果为1返回 如果不是1 计算当前值 如果不在范围内设为1返回 并且向下递归
if (Math.Abs(bmp.GetPixel(x, y).B - num) >50)
{
flag[x, y] = 2;
return;
}
else
{
flag[x, y] =1;
}
if (0 ==x || x == bmp.Width-1) return;
if(0==y||y==bmp.Height-1) return;
if (flag[x - 1, y] == 0)
{
fillsearch(bmp, x - 1, y, flag, num);
}
if (flag[x, y-1] == 0)
{
fillsearch(bmp, x , y-1, flag, num);
}
if (flag[x+1, y] == 0)
{
fillsearch(bmp, x+1, y, flag, num);
}
if (flag[x , y+1] == 0)
{
fillsearch(bmp, x , y+1, flag, num);
}
}
递归算法不太好用，小图片还可以。大图片我的机器上递归到1万多层就提示无法创建堆栈防护页。
非递归算法：
/// <summary>
/// 填充算法
/// </summary>
/// <param name="bmp"></param>
/// <param name="x"></param>
/// <param name="y"></param>
private Bitmap fillin(Bitmap bmp, int x, int y)
{
Bitmap map = new Bitmap(bmp.Width+2,bmp.Height+2);
for (int i = 0; i < bmp.Width; i++)
{
for (int j = 0; j < bmp.Height; j++)
{
map.SetPixel(i + 1, j + 1, bmp.GetPixel(i, j));
}
}
Byte[,] flag=new Byte[bmp.Width+2,bmp.Height+2];
for (int i = 0; i < map.Width; i++)
{
for (int j = 0; j < map.Height; j++)
{
flag[i, j] = 0;
}
}
for (int i = 0; i < map.Width; i++)
{
flag[i, 0] = 2;
flag[i, map.Height-1] = 2;
}
for (int i = 0; i < map.Height; i++)
{
flag[0, i] = 2;
flag[map.Width-1, i] = 2;
}
Stack<Point> colors = new Stack<Point>();
colors.Push(new Point(x,y));
int colorB = map.GetPixel(x, y).B;
while (colors.Count != 0)
{
x--;
if (flag[x, y] == 0)
{
if (Math.Abs(map.GetPixel(x, y).B - colorB) > 50)
{
flag[x, y] = 2;
}
else
{
flag[x, y] = 1;
colors.Push(new Point(x, y));
continue;
}
}
else {
x++;
}
y--;
if (flag[x, y] == 0)
{
if (Math.Abs(map.GetPixel(x, y).B - colorB) > 50)
{
flag[x, y] = 2;
}
else
{
flag[x, y] = 1;
colors.Push(new Point(x, y)); continue;
}
}
else { y++; }
x++;
if (flag[x, y] == 0)
{
if (Math.Abs(map.GetPixel(x, y).B - colorB) > 50)
{
flag[x, y] = 2;
}
else
{
flag[x, y] = 1;
colors.Push(new Point(x, y)); continue;
}
}
else
{
x--;
}
y++;
if (flag[x, y] == 0)
{
if (Math.Abs(map.GetPixel(x, y).B - colorB) > 50)
{
flag[x, y] = 2;
}
else
{
flag[x, y] = 1;
colors.Push(new Point(x, y)); continue;
}
}
else { y--; }
Point p= colors.Pop();
x = p.X;
y = p.Y;
}
Bitmap b = (Bitmap)bmp.Clone();
for (int i = 0; i < b.Width; i++)
{
for (int j = 0; j < b.Height; j++)
{
if (flag[i+1,j+1] == 1)
{
b.SetPixel(i, j, Color.FromArgb(255, 0, 0));
}
else if (flag[i+1, j+1] == 2)
{
b.SetPixel(i, j, Color.FromArgb(0, 255 , 0));
}
else
{
b.SetPixel(i, j, Color.FromArgb(0, 0, 255));
}
}
}
return b;
}
非递归算法，递归转递推。首先图片扩充一圈像素，设置已搜索的标记，简化边界判定。压栈出栈搜索。
测试结果
