使用OpenCV实现径向模糊

Question

我们想要校正数码相机中镜头引入的场曲.我们计划使用数字非锐化遮罩而不是应用高斯模糊我们想尝试径向模糊,因此锐化会对图像边缘产生更大的影响.

使用OpenCV创建径向模糊的最简单方法是什么？

Answer 1

上面的答案很接近,但遗漏了一些关键因素,让我想一想.我已经改变了地图,以便他们正确地计算缩放和缩小,并在每个位置从x和y添加/减去它们(否则你最终会将图像重新映射到一个小方块.我也改变了/ blur**模糊,否则你的地图将包含非常大的数字,而不是正确的(每个位置的极大倍数).

float center_x = width/2; //or whatever
float center_y = height/2;
float blur = 0.002; //blur radius per pixels from center. 2px blur at 1000px from center
int iterations = 5;

Mat growMapx, growMapy;
Mat shrinkMapx, shrinkMapy;
for(int x = 0; x < width; x++) {
  for(int y = 0; y < height; y++) {
    growMapx[x,y] = x+((x - center_x)*blur);
    growMapy[x,y] = y+((y - center_y)*blur);
    shrinkMapx[x,y] = x-((x - center_x)*blur);
    shrinkMapy[x,y] = y-((y - center_y)*blur);
  }
}

Mat tmp1, tmp2;
for(int i = 0; i < iterations; i++)  {
  remap(src, tmp1, growMapx, growMapy, CV_INTER_LINEAR); // enlarge
  remap(src, tmp2, shrinkMapx, shrinkMapy, CV_INTER_LINEAR); // shrink
  addWeighted(tmp1, 0.5, tmp2, 0.5, 0, src); // blend back to src
}

Answer 2

我对类似于 Photoshop 径向运动模糊的东西感兴趣。如果这也是您正在寻找的，我认为最好的解决方案可能是迭代resize和混合（addWeighted）。也可以通过 来完成remap。伪代码，或多或少：

float center_x = width/2; //or whatever
float center_y = height/2;
float blur = 0.02; //blur radius per pixels from center. 2px blur at 100px from center
int iterations = 5;

Mat mapx, mapy;
for(int x = 0; x < width; x++) {
   for(int y = 0; y < height; y++) {
       mapx[x,y] = (x - center_x)/blur;
       mapy[x,y] = (y - center_y)/blur;
   }
}

Mat tmp1, tmp2;
for(int i = 0; i < iterations; i++)  {
    remap(src, tmp1, mapx, mapy, CV_INTER_LINEAR); // enlarge
    remap(src, tmp2, -mapx, -mapy, CV_INTER_LINEAR); // shrink
    addWeighted(tmp1, 0.5, tmp2, 0.5, 0, src); // blend back to src
}