欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

C#图像处理之边缘检测(Sobel)的方法

程序员文章站 2022-05-26 15:20:14
本文实例讲述了c#图像处理之边缘检测(sobel)的方法。分享给大家供大家参考。具体如下: //定义sobel算子函数 private static bitma...

本文实例讲述了c#图像处理之边缘检测(sobel)的方法。分享给大家供大家参考。具体如下:

//定义sobel算子函数
private static bitmap sobel(bitmap a)
{
 int w = a.width;
 int h = a.height;
 try
 {
  bitmap dstbitmap = new bitmap(w, h, system.drawing.imaging.pixelformat.format24bpprgb);
  system.drawing.imaging.bitmapdata srcdata = a.lockbits(new rectangle
   (0, 0, w, h), system.drawing.imaging.imagelockmode.readonly, system.drawing.imaging.pixelformat.format24bpprgb);
  system.drawing.imaging.bitmapdata dstdata = dstbitmap.lockbits(new rectangle
   (0, 0, w, h), system.drawing.imaging.imagelockmode.writeonly, system.drawing.imaging.pixelformat.format24bpprgb);
  unsafe
  {
   byte* pin = (byte*)srcdata.scan0.topointer();
   byte* pout = (byte*)dstdata.scan0.topointer();
   byte* p;
   int stride = srcdata.stride;
   for (int y = 0; y < h; y++)
   {
   for (int x = 0; x < w; x++)
   {
    //边缘八个点像素不变
    if (x == 0 || x == w - 1 || y == 0 || y == h - 1)
    {
    pout[0] = pin[0];
    pout[1] = pin[1];
    pout[2] = pin[2];
    }
    else
    {
    int r0, r1, r2, r3, r4, r5, r6, r7, r8;
    int g1, g2, g3, g4, g5, g6, g7, g8, g0;
    int b1, b2, b3, b4, b5, b6, b7, b8, b0;
    double vr, vg, vb;
    //左上
    p = pin - stride - 3;
    r1 = p[2];
    g1 = p[1];
    b1 = p[0];
    //正上
    p = pin - stride;
    r2 = p[2];
    g2 = p[1];
    b2 = p[0];
    //右上
    p = pin - stride + 3;
    r3 = p[2];
    g3 = p[1];
    b3 = p[0];
    //左
    p = pin - 3;
    r4 = p[2];
    g4 = p[1];
    b4 = p[0];
    //右
    p = pin + 3;
    r5 = p[2];
    g5 = p[1];
    b5 = p[0];
    //左下
    p = pin + stride - 3;
    r6 = p[2];
    g6 = p[1];
    b6 = p[0];
    //正下
    p = pin + stride;
    r7 = p[2];
    g7 = p[1];
    b7 = p[0];
    // 右下 
    p = pin + stride + 3;
    r8 = p[2];
    g8 = p[1];
    b8 = p[0];
    //中心点
    p = pin;
    r0 = p[2];
    g0 = p[1];
    b0 = p[0];
    //使用模板
    vr = (double)(math .abs (r1+2*r4+r6-r3-2*r5-r8)+math .abs (r1+2*r2+r3-r6-2*r7-r8));
    vg = (double)(math .abs (g1+2*g4+g6-g3-2*g5-g8)+math .abs (g1+2*g2+g3-g6-2*g7-g8));
    vb = (double)(math .abs (b1+2*b4+b6-b3-2*b5-b8)+math .abs (b1+2*b2+b3-b6-2*b7-b8));
    if (vr > 0)
    {
     vr = math.min(255, vr);
    }
    else
    {
     vr = math.max(0, vr);
    }
    if (vg > 0)
    {
     vg = math.min(255, vg);
    }
    else
    {
     vg = math.max(0, vg);
    }
    if (vb > 0)
    {
     vb = math.min(255, vb);
    }
    else
    {
     vb = math.max(0, vb);
    }
    pout[0] = (byte)vb;
    pout[1] = (byte)vg;
    pout[2] = (byte)vr;
    }
    pin += 3;
    pout += 3;
   }
   pin += srcdata.stride - w * 3;
   pout += srcdata.stride - w * 3;
   }
  }
  a.unlockbits(srcdata);
  dstbitmap.unlockbits(dstdata);
  return dstbitmap;
 }
 catch
 {
  return null;
 }
}

希望本文所述对大家的c#程序设计有所帮助。