Matlab-8x8窗口并寻找均值 [英] Matlab - 8x8 window and finding mean

问题描述

说我有一个图像矩阵，我想做以下事情:

Say I have a matrix of an image, and I want to do the following:

• 在矩阵上滑动8x8窗口
• 计算矩阵中每个像素的平均值

如果我是Matlab编码的新手，那么如何在matlab中做到这一点.

How can I do that in matlab, provided that I'm kind of new to coding in matlab.

谢谢.

推荐答案

您还可以使用

You can also use nlfilter :

fun = @(x) mean(x(:)); 
ans= nlfilter(img,[8 8],fun);

但是，正如@ s.bandara所建议的，conv2的计算速度快得多，...用于计算均值... 请注意，将conv2与valid一起使用时，矩阵大小将发生变化.

But as @s.bandara suggested, the conv2 is much faster for just calculating the mean... Note that the matrix size will change when using the conv2 with valid.

nlfilter经过时间为0.433989秒.

nlfilter Elapsed time is 0.433989 seconds.

conv2经过时间为0.000803秒.

conv2 Elapsed time is 0.000803 seconds.

因此很明显，对于寻找均值的任务，conv2要快得多.

So it is pretty obvious that for the task of finding the mean, conv2 is much much faster.

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