using System.Drawing;
using System.Drawing.Imaging;
using System.Web.Mvc;
namespace MVC2017_Sample.Controllers
{
 public class DefaultController : Controller
 {
  public ActionResult Index()
  {
   //原圖
   Image img = Image.FromFile("c:\\1.jpg");
   Bitmap map = new Bitmap(img);
   //馬賽克處理后的圖片   Image img2 = AdjustTobMosaic(map, 20);
   img2.Save("c:\\1_bak.jpg", ImageFormat.Jpeg);
   return View();
  }
  /// <summary>
  /// 馬賽克處理
  /// </summary>
  /// <param name="bitmap"></param>
  /// <param name="effectWidth"> 影響范圍 每一個格子數 </param>
  /// <returns></returns>
  public Bitmap AdjustTobMosaic(System.Drawing.Bitmap bitmap, int effectWidth)
  {
   // 差異最多的就是以照一定范圍取樣 玩之后直接去下一個范圍
   for (int heightOfffset = 0; heightOfffset < bitmap.Height; heightOfffset += effectWidth)
   {
    for (int widthOffset = 0; widthOffset < bitmap.Width; widthOffset += effectWidth)
    {
     int avgR = 0, avgG = 0, avgB = 0;
     int blurPixelCount = 0;
     for (int x = widthOffset; (x < widthOffset + effectWidth && x < bitmap.Width); x++)
     {
      for (int y = heightOfffset; (y < heightOfffset + effectWidth && y < bitmap.Height); y++)
      {
       System.Drawing.Color pixel = bitmap.GetPixel(x, y);
       avgR += pixel.R;
       avgG += pixel.G;
       avgB += pixel.B;
       blurPixelCount++;
      }
     }
     // 計算范圍平均
     avgR = avgR / blurPixelCount;
     avgG = avgG / blurPixelCount;
     avgB = avgB / blurPixelCount;
     // 所有范圍內都設定此值
     for (int x = widthOffset; (x < widthOffset + effectWidth && x < bitmap.Width); x++)
     {
      for (int y = heightOfffset; (y < heightOfffset + effectWidth && y < bitmap.Height); y++)
      {
       System.Drawing.Color newColor = System.Drawing.Color.FromArgb(avgR, avgG, avgB);
       bitmap.SetPixel(x, y, newColor);
      }
     }
    }
   }
   return bitmap;
  }
 }
}