c#实现一个超实用的证件照换底色小工具（附源码）

/// <summary>
  /// 获取前五排像素，求出rgb范围
  /// </summary>
  /// <param name="path"></param>
  /// <returns></returns>
  private List<int> GetModeColor(string path)
  {
   List<int> colorrgb = new List<int>();
   List<int> rlist=new List<int>();
   List<int> glist = new List<int>();
   List<int> blist = new List<int>();
   using (Bitmap map = (Bitmap)Image.FromFile(path))
   {
    using (Bitmap editMap = new Bitmap(map, map.Width, map.Height))
    {
     // editMap.GetPixel()
     for (int i = 0; i < map.Width; i++)
     {
      for (int j = 0; j <5; j++)
      {
       Color color = editMap.GetPixel(i, j);
       if (!rlist.Contains(color.R))
       {
        rlist.Add(color.R);
       }
       if (!glist.Contains(color.G))
       {
        glist.Add(color.G);
       }
       if (!blist.Contains(color.B))
       {
        blist.Add(color.B);
       }
      }
     }
     //添加rgb像素范围
     colorrgb.Add(rlist.Max());
     colorrgb.Add(glist.Max());
     colorrgb.Add(blist.Max());
     colorrgb.Add(rlist.Min());
     colorrgb.Add(glist.Min());
     colorrgb.Add(blist.Min());
    }
   }
   return colorrgb;
  }

/// <summary>
  /// 预览结果
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void button3_Click(object sender, EventArgs e)
  {
   if (string.IsNullOrEmpty(label1.Text))
   {
    MessageBox.Show("请选择颜色");
    return;
   }   
   if (string.IsNullOrEmpty(imagePath))
   {
    MessageBox.Show("请上传证件");
    return;
   }   
   int upnum = Convert.ToInt32(textBox1.Text);
   int downnum = Convert.ToInt32(textBox2.Text);
   double trackvalue = Convert.ToDouble(trackBar1.Value);
   List<int> colorrgb = GetModeColor(imagePath);
   //上半部分去除颜色范围
   List<int> upcolorrgb = new List<int>();
   //下半部分去除颜色范围
   List<int> downcolorrgb = new List<int>();
   for (int i = 0; i < colorrgb.Count; i++)
   {
    if (i>2)
    {

     upcolorrgb.Add(colorrgb[i]-upnum<0?0: colorrgb[i] - upnum);
     downcolorrgb.Add(colorrgb[i] - downnum < 0 ? 0 : colorrgb[i] - downnum);
    }
    else
    {
     upcolorrgb.Add(colorrgb[i] + upnum >255 ? 255 : colorrgb[i] + upnum);
     downcolorrgb.Add(colorrgb[i] + downnum > 255 ? 255 : colorrgb[i] + downnum);
    }
   }
   //从左到右，从上到下读取像素点
   using (Bitmap map = (Bitmap)Image.FromFile(imagePath))
   {
    using (Bitmap editMap = new Bitmap(map, map.Width, map.Height))
    {
     // 上半部分
     for (int i = 0; i < map.Width; i++)
     {
      for (int j = 0; j < (int)(map.Height * (trackvalue/100)); j++)
      {
       Color color = editMap.GetPixel(i, j);
       //判断像素是否可以移除
       if (color.R >= upcolorrgb[3] && color.R <= upcolorrgb[0] &&
        color.G >= upcolorrgb[4] && color.G <= upcolorrgb[1] &&
        color.B >= upcolorrgb[5] && color.B <= upcolorrgb[2])
       {
        editMap.SetPixel(i, j, tempcolor);
       }
      }
     }
     //下半部分
     for (int i = 0; i < map.Width; i++)
     {
      for (int j = (int)(map.Height * (trackvalue / 100)); j <map.Height ; j++)
      {
       //判断像素是否可以移除
       Color color = editMap.GetPixel(i, j);
       if (color.R >= downcolorrgb[3] && color.R <= downcolorrgb[0] &&
        color.G >= downcolorrgb[4] && color.G <= downcolorrgb[1] &&
        color.B >= downcolorrgb[5] && color.B <= downcolorrgb[2])
       {
        editMap.SetPixel(i, j, tempcolor);

       }
      }
     }
     //保存
     string savepath = System.Environment.CurrentDirectory+@"\result\" + DateTime.Now.ToString("yyyyMMddHHmmssffff") + ".png";
     editMap.Save(savepath);
     resultPath = savepath;
     pictureBox2.Image = Image.FromFile(savepath);
    }
   }
  }