/// <summary>
/// 全局阈值图像二值化
/// </summary>
/// <param name="bmp">原始图像</param>
/// <param name="method">二值化方法</param>
/// <param name="threshold">输出：全局阈值</param>
/// <returns>二值化后的图像数组</returns>
public static Byte[,] ToBinaryArray(this Bitmap bmp, BinarizationMethods method, out Int32 threshold)
{ // 位图转换为灰度数组
Byte[,] GrayArray = bmp.ToGrayArray();
// 计算全局阈值
if (method == BinarizationMethods.Otsu)
{
threshold = OtsuThreshold(GrayArray);
}
else
{
threshold = IterativeThreshold(GrayArray);
}
// 根据阈值进行二值化
Int32 PixelHeight = bmp.Height;
Int32 PixelWidth = bmp.Width;
Byte[,] BinaryArray = new Byte[PixelHeight, PixelWidth];
for (Int32 i = 0; i < PixelHeight; i++)
{
for (Int32 j = 0; j < PixelWidth; j++)
{
BinaryArray[i, j] = Convert.ToByte((GrayArray[i, j] > threshold) ? 255 : 0);
}
}
return(BinaryArray);
}
/// <summary>
/// 全局阈值图像二值化
/// </summary>
/// <param name="bmp">原始图像</param>
/// <param name="method">二值化方法</param>
/// <param name="threshold">输出：全局阈值</param>
/// <returns>二值化图像</returns>
public static Bitmap ToBinaryBitmap(this Bitmap bmp, BinarizationMethods method, out Int32 threshold)
{ // 位图转换为灰度数组
Byte[,] GrayArray = bmp.ToGrayArray();
// 计算全局阈值
if (method == BinarizationMethods.Otsu)
{
threshold = OtsuThreshold(GrayArray);
}
else
{
threshold = IterativeThreshold(GrayArray);
}
// 将灰度数组转换为二值数据
Int32 PixelHeight = bmp.Height;
Int32 PixelWidth = bmp.Width;
Int32 Stride = ((PixelWidth + 31) >> 5) << 2;
Byte[] Pixels = new Byte[PixelHeight * Stride];
for (Int32 i = 0; i < PixelHeight; i++)
{
Int32 Base = i * Stride;
for (Int32 j = 0; j < PixelWidth; j++)
{
if (GrayArray[i, j] > threshold)
{
Pixels[Base + (j >> 3)] |= Convert.ToByte(0x80 >> (j & 0x7));
}
}
}
// 从二值数据中创建黑白图像
Bitmap BinaryBmp = new Bitmap(PixelWidth, PixelHeight, PixelFormat.Format1bppIndexed);
// 设置调色表
ColorPalette cp = BinaryBmp.Palette;
cp.Entries[0] = Color.Black; // 黑色
cp.Entries[1] = Color.White; // 白色
BinaryBmp.Palette = cp;
// 设置位图图像特性
BitmapData BinaryBmpData = BinaryBmp.LockBits(new Rectangle(0, 0, PixelWidth, PixelHeight), ImageLockMode.WriteOnly, PixelFormat.Format1bppIndexed);
Marshal.Copy(Pixels, 0, BinaryBmpData.Scan0, Pixels.Length);
BinaryBmp.UnlockBits(BinaryBmpData);
return(BinaryBmp);
}
/// <summary>
/// 全局阈值图像二值化
/// </summary>
/// <param name="bmp">原始图像</param>
/// <param name="method">二值化方法</param>
/// <param name="threshold">输出：全局阈值</param>
/// <returns>二值化后的图像数组</returns>
public static Byte[,] ToBinaryArray(this Bitmap bmp, BinarizationMethods method, out Int32 threshold)
{ // 位图转换为灰度数组
Byte[,] GrayArray = bmp.ToGrayArray();
// 计算全局阈值
if (method == BinarizationMethods.Otsu)
threshold = OtsuThreshold(GrayArray);
else
threshold = IterativeThreshold(GrayArray);
// 根据阈值进行二值化
Int32 PixelHeight = bmp.Height;
Int32 PixelWidth = bmp.Width;
Byte[,] BinaryArray = new Byte[PixelHeight, PixelWidth];
for (Int32 i = 0; i < PixelHeight; i++)
{
for (Int32 j = 0; j < PixelWidth; j++)
{
BinaryArray[i, j] = Convert.ToByte((GrayArray[i, j] > threshold) ? 255 : 0);
}
}
return BinaryArray;
}
/// <summary>
/// 全局阈值图像二值化
/// </summary>
/// <param name="bmp">原始图像</param>
/// <param name="method">二值化方法</param>
/// <param name="threshold">输出：全局阈值</param>
/// <returns>二值化图像</returns>
public static Bitmap ToBinaryBitmap(this Bitmap bmp, BinarizationMethods method, out Int32 threshold)
{ // 位图转换为灰度数组
Byte[,] GrayArray = bmp.ToGrayArray();
// 计算全局阈值
if (method == BinarizationMethods.Otsu)
threshold = OtsuThreshold(GrayArray);
else
threshold = IterativeThreshold(GrayArray);
// 将灰度数组转换为二值数据
Int32 PixelHeight = bmp.Height;
Int32 PixelWidth = bmp.Width;
Int32 Stride = ((PixelWidth + 31) >> 5) << 2;
Byte[] Pixels = new Byte[PixelHeight * Stride];
for (Int32 i = 0; i < PixelHeight; i++)
{
Int32 Base = i * Stride;
for (Int32 j = 0; j < PixelWidth; j++)
{
if (GrayArray[i, j] > threshold)
{
Pixels[Base + (j >> 3)] |= Convert.ToByte(0x80 >> (j & 0x7));
}
}
}
// 从二值数据中创建黑白图像
Bitmap BinaryBmp = new Bitmap(PixelWidth, PixelHeight, PixelFormat.Format1bppIndexed);
// 设置调色表
ColorPalette cp = BinaryBmp.Palette;
cp.Entries[0] = Color.Black; // 黑色
cp.Entries[1] = Color.White; // 白色
BinaryBmp.Palette = cp;
// 设置位图图像特性
BitmapData BinaryBmpData = BinaryBmp.LockBits(new Rectangle(0, 0, PixelWidth, PixelHeight), ImageLockMode.WriteOnly, PixelFormat.Format1bppIndexed);
Marshal.Copy(Pixels, 0, BinaryBmpData.Scan0, Pixels.Length);
BinaryBmp.UnlockBits(BinaryBmpData);
return BinaryBmp;
}
