/// <summary>
/// 图形细化
/// </summary>
/// <param name="srcImg"></param>
/// <returns></returns>
public unsafe Bitmap ToThinner(Bitmap srcImg)
{
int iw = srcImg.Width;
int ih = srcImg.Height;
bool bModified; //二值图像修改标志
bool bCondition1; //细化条件1标志
bool bCondition2; //细化条件2标志
bool bCondition3; //细化条件3标志
bool bCondition4; //细化条件4标志
int nCount;
//5X5像素块
byte[,] neighbour = new byte[, ];
//新建临时存储图像
Bitmap NImg = new Bitmap(iw, ih, srcImg.PixelFormat);
bModified = true;
//细化修改标志, 用作循环条件
BitmapData dstData = srcImg.LockBits(new Rectangle(, , iw, ih), ImageLockMode.ReadWrite, srcImg.PixelFormat);
byte* data = (byte*)(dstData.Scan0);
//将图像转换为0,1二值得图像;
int step = dstData.Stride;
for (int i = ; i < dstData.Height; i++)
{
for (int j = ; j < dstData.Width * ; j += )
{
if (data[i * step + j] > )
//如果是白线条，只要将0改成1，将1改成0
data[i * step + j]
= data[i * step + j + ]
= data[i * step + j + ]
= ;
else
data[i * step + j]
= data[i * step + j + ]
= data[i * step + j + ]
= ;
}
} BitmapData dstData1 = NImg.LockBits(new Rectangle(, , iw, ih), ImageLockMode.ReadWrite, NImg.PixelFormat);
byte* data1 = (byte*)(dstData1.Scan0);
int step1 = dstData1.Stride;
//细化循环开始
while (bModified)
{
bModified = false;
//初始化临时二值图像NImg
for (int i = ; i < dstData1.Height; i++)
{
for (int j = ; j < dstData1.Width * ; j++)
{
data1[i * step1 + j] = ;
}
}
for (int i = ; i < ih - ; i++)
{
for (int j = ; j < iw * - ; j += )
{
bCondition1 = false;
bCondition2 = false;
bCondition3 = false;
bCondition4 = false;
if (data[i * step + j] == )
//若图像的当前点为白色，则跳过
continue;
for (int k = ; k < ; k++)
{
//取以当前点为中心的5X5块
for (int l = ; l < ; l++)
{
//1代表黑色, 0代表白色
//neighbour[k, l] = bw[i + k - 2, j + l - 2];
//neighbour[k, l] = data[(i + k - 2) * step + (j + l - 2)];
neighbour[k, l] = data[(i + k - ) * step + (j + l * - )];
}
}
//(1)判断条件2<=n(p)<=6
nCount = neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ] + neighbour[, ];
if (nCount >= && nCount <= )
bCondition1 = true;
else
{
data1[i * step1 + j] = ;
continue;
//跳过, 加快速度
}
//(2)判断s(p)=1
nCount = ;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (nCount == )
bCondition2 = true;
else
{
data1[i * step1 + j] = ;
continue;
}
//(3)判断p0*p2*p4=0 or s(p2)!=1
if (neighbour[, ] * neighbour[, ] * neighbour[, ] == )
bCondition3 = true;
else
{
nCount = ;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (nCount != )
//s(p2)!=1
bCondition3 = true;
else
{
data1[i * step1 + j] = ;
continue;
}
}
//(4)判断p2*p4*p6=0 or s(p4)!=1
if (neighbour[, ] * neighbour[, ] * neighbour[, ] == )
bCondition4 = true;
else
{
nCount = ;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (neighbour[, ] == && neighbour[, ] == )
nCount++;
if (nCount != )//s(p4)!=1
bCondition4 = true;
}
if (bCondition1 && bCondition2 && bCondition3 && bCondition4)
{
data1[i * step1 + j] = ;
bModified = true;
}
else
{
data1[i * step1 + j] = ;
}
}
}
// 将细化了的临时图像bw_tem[w,h]copy到bw[w,h],完成一次细化
for (int i = ; i < ih - ; i++)
for (int j = ; j < iw * - ; j++)
data[i * step + j] = data1[i * step1 + j];
}
for (int i = ; i < ih - ; i++)
{
for (int j = ; j < iw * - ; j += )
{
if (data[i * step + j] == ) data[i * step + j]
= data[i * step + j + ]
= data[i * step + j + ]
= ; else data[i * step + j]
= data[i * step + j + ]
= data[i * step + j + ]
= ; }
}
srcImg.UnlockBits(dstData);
NImg.UnlockBits(dstData1);
return (srcImg);
}