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# Sobel算法

private void Sobel(Bitmap img) {
int width = img.Width;
int height = img.Height;

int[,] Gx = new int[3, 3]{ {-1, 0, 1 },
{-2, 0, 2 } ,
{-1, 0, 1 } };

int[,] Gy = new int[3, 3]{ {-1,-2,-1},
{ 0, 0, 0 },
{ 1, 2, 1}};

int[,] TotalGx = new int[img.Width, img.Height];
int[,] TotalGy = new int[img.Width, img.Height];
int[,] GTotal = new int[img.Width, img.Height];

Bitmap bitmapTemp = new Bitmap(img.Width, img.Height, PixelFormat.Format24bppRgb);

LockBitmap lockBitmap1 = new LockBitmap(bitmapTemp);
lockBitmap1.LockBits();

LockBitmap lockBitmap = new LockBitmap(img);
lockBitmap.LockBits();
for (int i = 1; i < img.Width - 1; i++)
{
for (int j = 1; j < img.Height - 1; j++)
{
Color a = lockBitmap.GetPixel(i - 1, j - 1);//[0][0]
Color b = lockBitmap.GetPixel(i - 1, j);    //[0][1]
Color c = lockBitmap.GetPixel(i - 1, j + 1);//[0][2]

Color d = lockBitmap.GetPixel(i, j - 1);    //[1][0]
Color f = lockBitmap.GetPixel(i, j);        //[1][1]
Color g = lockBitmap.GetPixel(i, j + 1);    //[1][2]

Color h = lockBitmap.GetPixel(i + 1, j - 1);//[2][0]
Color l = lockBitmap.GetPixel(i + 1, j);    //[2][1]
Color n = lockBitmap.GetPixel(i + 1, j + 1); //[2][2]

TotalGx[i, j] = Gx[0, 0] * Avg(a) + Gx[0, 1] * Avg(b) + Gx[0, 2] * Avg(c)
+ Gx[1, 0] * Avg(d) + Gx[1, 1] * Avg(f) + Gx[1, 2] * Avg(g)
+ Gx[2, 0] * Avg(h) + Gx[2, 1] * Avg(l) + Gx[2, 2] * Avg(n);

//if (TotalGx[i, j] < 0) { TotalGx[i, j] = 0; }
//if (TotalGx[i, j] > 255) { TotalGx[i, j] = 255; }

TotalGy[i, j] = Gy[0, 0] * Avg(a) + Gy[0, 1] * Avg(b) + Gy[0, 2] * Avg(c)
+ Gy[1, 0] * Avg(d) + Gy[1, 1] * Avg(f) + Gy[1, 2] * Avg(g)
+ Gy[2, 0] * Avg(h) + Gy[2, 1] * Avg(l) + Gy[2, 2] * Avg(n);

//if (TotalGy[i, j] < 0) { TotalGy[i, j] = 0; }
//if (TotalGy[i, j] > 255) { TotalGy[i, j] = 255; }

//GTotal[i, j] = TotalGx[i, j] + TotalGy[i, j];
GTotal[i, j] = (int)Math.Sqrt(TotalGx[i, j] * TotalGx[i, j] + TotalGy[i, j] * TotalGy[i, j]);

if (GTotal[i, j] >= 255)
{ GTotal[i, j] = 255; }

if (GTotal[i, j] < 0)
{ GTotal[i, j] = 0; }
//bitmapTemp.SetPixel(i, j, Color.FromArgb(GTotal[i, j], GTotal[i ,j], GTotal[i, j]));
lockBitmap1.SetPixel(i, j, Color.FromArgb(GTotal[i, j], GTotal[i, j], GTotal[i, j]));
}
}
lockBitmap1.UnlockBits();
lockBitmap.UnlockBits();
pictureBox2.Image = lockBitmap1.GetBitmap();

}

public class LockBitmap
{
Bitmap source = null;
IntPtr Iptr = IntPtr.Zero;
BitmapData bitmapData = null;

public byte[] Pixels { get; set; }
public int Depth { get; private set; }
public int Width { get; private set; }
public int Height { get; private set; }

public LockBitmap(Bitmap source)
{
this.source = source;
}

public Bitmap GetBitmap() { return this.source; }

/// <summary>
/// Lock bitmap data
/// </summary>
public void LockBits()
{
try
{
// Get width and height of bitmap
Width = source.Width;
Height = source.Height;

// get total locked pixels count
int PixelCount = Width * Height;

// Create rectangle to lock
Rectangle rect = new Rectangle(0, 0, Width, Height);

// get source bitmap pixel format size
Depth = System.Drawing.Bitmap.GetPixelFormatSize(source.PixelFormat);

// Check if bpp (Bits Per Pixel) is 8, 24, or 32
if (Depth != 8 && Depth != 24 && Depth != 32)
{
throw new ArgumentException("Only 8, 24 and 32 bpp images are supported.");
}

// Lock bitmap and return bitmap data
source.PixelFormat);

// create byte array to copy pixel values
int step = Depth / 8;
Pixels = new byte[PixelCount * step];
Iptr = bitmapData.Scan0;

// Copy data from pointer to array
Marshal.Copy(Iptr, Pixels, 0, Pixels.Length);
}
catch (Exception ex)
{
throw ex;
}
}

/// <summary>
/// Unlock bitmap data
/// </summary>
public void UnlockBits()
{
try
{
// Copy data from byte array to pointer
Marshal.Copy(Pixels, 0, Iptr, Pixels.Length);

// Unlock bitmap data
source.UnlockBits(bitmapData);
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// Get the color of the specified pixel
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public Color GetPixel(int x, int y)
{
Color clr = Color.Empty;

// Get color components count
int cCount = Depth / 8;

// Get start index of the specified pixel
int i = ((y * Width) + x) * cCount;

if (i > Pixels.Length - cCount)
throw new IndexOutOfRangeException();

if (Depth == 32) // For 32 bpp get Red, Green, Blue and Alpha
{
byte b = Pixels[i];
byte g = Pixels[i + 1];
byte r = Pixels[i + 2];
byte a = Pixels[i + 3]; // a
clr = Color.FromArgb(a, r, g, b);
}
if (Depth == 24) // For 24 bpp get Red, Green and Blue
{
byte b = Pixels[i];
byte g = Pixels[i + 1];
byte r = Pixels[i + 2];
clr = Color.FromArgb(r, g, b);
}
if (Depth == 8)
// For 8 bpp get color value (Red, Green and Blue values are the same)
{
byte c = Pixels[i];
clr = Color.FromArgb(c, c, c);
}
return clr;
}

/// <summary>
/// Set the color of the specified pixel
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="color"></param>
public void SetPixel(int x, int y, Color color)
{
// Get color components count
int cCount = Depth / 8;

// Get start index of the specified pixel
int i = ((y * Width) + x) * cCount;

if (Depth == 32) // For 32 bpp set Red, Green, Blue and Alpha
{
Pixels[i] = color.B;
Pixels[i + 1] = color.G;
Pixels[i + 2] = color.R;
Pixels[i + 3] = color.A;
}
if (Depth == 24) // For 24 bpp set Red, Green and Blue
{
Pixels[i] = color.B;
Pixels[i + 1] = color.G;
Pixels[i + 2] = color.R;
}
if (Depth == 8)
// For 8 bpp set color value (Red, Green and Blue values are the same)
{
Pixels[i] = color.B;
}
}

//public Color GetPixel(int x, int y)
//{
//    unsafe
//    {
//        byte* ptr = (byte*)Iptr;
//        ptr = ptr + bitmapData.Stride * y;
//        ptr += Depth * x / 8;
//        Color c = Color.Empty;
//        if (Depth == 32)
//        {
//            int a = ptr[3];
//            int r = ptr[2];
//            int g = ptr[1];
//            int b = ptr[0];
//            c = Color.FromArgb(a, r, g, b);
//        }
//        else if (Depth == 24)
//        {
//            int r = ptr[2];
//            int g = ptr[1];
//            int b = ptr[0];
//            c = Color.FromArgb(r, g, b);
//        }
//        else if (Depth == 8)
//        {
//            int r = ptr[0];
//            c = Color.FromArgb(r, r, r);
//        }
//        return c;
//    }
//}

//public void SetPixel(int x, int y, Color c)
//{
//    unsafe
//    {
//        byte* ptr = (byte*)Iptr;
//        ptr = ptr + bitmapData.Stride * y;
//        ptr += Depth * x / 8;
//        if (Depth == 32)
//        {
//            ptr[3] = c.A;
//            ptr[2] = c.R;
//            ptr[1] = c.G;
//            ptr[0] = c.B;
//        }
//        else if (Depth == 24)
//        {
//            ptr[2] = c.R;
//            ptr[1] = c.G;
//            ptr[0] = c.B;
//        }
//        else if (Depth == 8)
//        {
//            ptr[2] = c.R;
//            ptr[1] = c.G;
//            ptr[0] = c.B;
//        }
//    }
//}

//return data[((width * y) + x) * 4 + i];
}

posted @ 2018-04-25 10:17  FourOne  阅读(584)  评论(0编辑  收藏