C#对图片进行马赛克处理，可控制模糊程度

using System.Drawing;
using System.Drawing.Imaging;
using System.Web.Mvc;

namespace MVC2017_Sample.Controllers
{
public class DefaultController : Controller
{
public ActionResult Index()
{
//原图
Image img = Image.FromFile("c:\\1.jpg");
Bitmap map = new Bitmap(img);
//马赛克处理后的图片
Image img2 = AdjustTobMosaic(map, 20);
img2.Save("c:\\1_bak.jpg", ImageFormat.Jpeg);
return View();
}

/// <summary>
/// 马赛克处理
/// </summary>
/// <param name="bitmap"></param>
/// <param name="effectWidth"> 影响范围 每一个格子数 </param>
/// <returns></returns>
public Bitmap AdjustTobMosaic(System.Drawing.Bitmap bitmap, int effectWidth)
{
// 差异最多的就是以照一定范围取样 玩之后直接去下一个范围
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++;
}
}

// 计算范围平均
avgR = avgR / blurPixelCount;
avgG = avgG / blurPixelCount;
avgB = avgB / blurPixelCount;

// 所有范围内都设定此值
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;
}
}
}