在C ++/C中模糊图像 [英] Bluring an image in C++/C

问题描述

所以我正在盯着一个有关使用C ++进行图像处理的项目.

So I'm staring a project about image processing with C++.

问题是，我在网上找到的所有相关信息(在C ++中将图像模糊化)都随CUDA或OpenCV一起提供.

The thing is that everything I find online about this matter (blurring an image in C++) comes either with CUDA or with OpenCV.

有没有一种方法可以仅使用C ++来模糊图像?(对于初学者)

Is there a way to blur an image with C++ only? (for starters)

如果是，可以请他人分享代码或进行解释吗?

If yes, can somebody please share the code or explain?

谢谢！

推荐答案

首先，您需要在内存中存储图像.

Firstly you need the image in memory.

然后，您需要第二个缓冲区用作工作区.

Then you need a second buffer to use as a workspace.

然后，您需要一个过滤器.常见的过滤器是

Then you need a filter. A common filter would be

          1   4  1
          4 -20  4
          1   4  1

对于每个像素，我们应用滤镜.因此，我们将图像设置为周围像素的加权平均值，然后进行减法以避免整个图像变亮或变暗.

For each pixel, we apply the filter. So we're setting the image to a weighted average of the pixels around it, then subtracting to avoid the overall image going lighter or darker.

应用小型过滤器非常简单.

Applying a small filter is very simple.

          for(y=0;y<height;y++)
            for(x=0;x<width;x++)
            {
               total = image[(y+1)*width+x+1];
               for(fy=0; fy < 3; fy++)
                 for(fx = 0; fx < 3; fx++)
                   total += image[(y+fy)*width+x+fx] * filter[fy*3+x];
              output[(y+1)*width+x+1] = clamp(total, 0, 255);

            }

您需要对边缘进行特殊处理，这很简单，但没有增加任何理论上的复杂性.

You need to special case the edges, which is just fiddly but doesn't add any theoretical complexity.

当我们使用较幼稚的算法更快时，正确设置边缘变得很重要.然后，您可以在频域中进行计算，使用大型滤波器可以更快地进行计算.

When we use faster algorithms that the naive one it becomes important to set up edges correctly. You then do the calculations in the frequency domain and it's a lot faster with a big filter.

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