public class EdgeDetect : ImageInfo { /************************************************************ * * Roberts, Sobel, Prewitt, Kirsch, GaussLaplacian * 水平检测、垂直检测、边缘增强、边缘均衡化 * ************************************************************/
/// /// 对两幅图像进行梯度运算 /// /// 位图 1 /// 位图 2 /// private Bitmap Gradient(Bitmap b1, Bitmap b2) {
int width = b1.Width; int height = b1.Height;
BitmapData data1 = b1.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb); BitmapData data2 = b2.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
unsafe { byte* p1 = (byte*)data1.Scan0; byte* p2 = (byte*)data2.Scan0;
int offset = data1.Stride - width * BPP; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { for (int i = 0; i < 3; i++) { int power = (int)Math.Sqrt((p1[i] * p1[i] + p2[i] * p2[i])); p1[i] = (byte)(power > 255 ? 255 : power); } // i p1 += BPP; p2 += BPP; } // x
p1 += offset; p2 += offset; } // y }
b1.UnlockBits(data1); b2.UnlockBits(data2);
Bitmap dstImage = (Bitmap)b1.Clone(); b1.Dispose(); b2.Dispose();
return dstImage; } // end of Gradient
/// /// 按 Roberts 算子进行边缘检测 /// /// 位图流 /// public Bitmap Roberts(Bitmap b) { int width = b.Width; int height = b.Height;
Bitmap dstImage = new Bitmap(width, height); BitmapData srcData = b.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb); BitmapData dstData = dstImage.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
int stride = srcData.Stride; int offset = stride - width * BPP;
unsafe { byte* src = (byte*)srcData.Scan0; byte* dst = (byte*)dstData.Scan0;
int A, B; // A(x-1, y-1) B(x, y-1) int C, D; // C(x-1, y) D(x, y) // 指向第一行 src += stride; dst += stride;
// 不处理最上边和最左边 for (int y = 1; y < height; y++) { // 指向每行第一列 src += BPP; dst += BPP; for (int x = 1; x < width; x++) { for (int i = 0; i < 3; i++) { A = src[i - stride - BPP]; B = src[i - stride]; C = src[i - BPP]; D = src[i];
dst[i] = (byte)(Math.Sqrt((A - D) * (A - D) + (B - C) * (B - C))); } // i
dst[3] = src[3]; src += BPP; dst += BPP; } // x
src += offset; dst += offset; } // y }
b.UnlockBits(srcData); dstImage.UnlockBits(dstData);
b.Dispose(); return dstImage; } // end of Roberts
/// /// 按 Sobel 算子进行边缘检测 /// /// 位图流 /// public Bitmap Sobel(Bitmap b) { Matrix3x3 m = new Matrix3x3();
// -1 -2 -1 // 0 0 0 // 1 2 1 m.Init(0); m.TopLeft = m.TopRight = -1; m.BottomLeft = m.BottomRight = 1; m.TopMid = -2; m.BottomMid = 2; Bitmap b1 = m.Convolute((Bitmap)b.Clone());
// -1 0 1 // -2 0 2 // -1 0 1 m.Init(0); m.TopLeft = m.BottomLeft = -1; m.TopRight = m.BottomRight = 1; m.MidLeft = -2; m.MidRight = 2; Bitmap b2 = m.Convolute((Bitmap)b.Clone());
// 0 1 2 // -1 0 1 // -2 -1 0 m.Init(0); m.TopMid = m.MidRight = 1; m.MidLeft = m.BottomMid = -1; m.TopRight = 2; m.BottomLeft = -2; Bitmap b3 = m.Convolute((Bitmap)b.Clone());
// -2 -1 0 // -1 0 1 // 0 1 2 m.Init(0); m.TopMid = m.MidLeft = -1; m.MidRight = m.BottomMid = 1; m.TopLeft = -2; m.BottomRight = 2; Bitmap b4 = m.Convolute((Bitmap)b.Clone());
// 梯度运算 b = Gradient(Gradient(b1, b2), Gradient(b3, b4));
b1.Dispose(); b2.Dispose(); b3.Dispose(); b4.Dispose(); return b; } // end of Sobel
/// /// 按 Prewitt 算子进行边缘检测 /// /// 位图流 /// public Bitmap Prewitt(Bitmap b) { Matrix3x3 m = new Matrix3x3();
// -1 -1 -1 // 0 0 0 // 1 1 1 m.Init(0); m.TopLeft = m.TopMid = m.TopRight = -1; m.BottomLeft = m.BottomMid = m.BottomRight = 1; Bitmap b1 = m.Convolute((Bitmap)b.Clone());
// -1 0 1 // -1 0 1 // -1 0 1 m.Init(0); m.TopLeft = m.MidLeft = m.BottomLeft = -1; m.TopRight = m.MidRight = m.BottomRight = 1; Bitmap b2 = m.Convolute((Bitmap)b.Clone());
// -1 -1 0 // -1 0 1 // 0 1 1 m.Init(0); m.TopLeft = m.MidLeft = m.TopMid = -1; m.BottomMid = m.BottomRight = m.MidRight = 1; Bitmap b3 = m.Convolute((Bitmap)b.Clone());
// 0 1 1 // -1 0 1 // -1 -1 0 m.Init(0); m.TopMid = m.TopRight = m.MidRight = 1; m.MidLeft = m.BottomLeft = m.BottomMid = -1; Bitmap b4 = m.Convolute((Bitmap)b.Clone());
// 梯度运算 b = Gradient(Gradient(b1, b2), Gradient(b3, b4));
