calculation of mean , standard deviation and average for each pixel in an image M*N?

2 次查看（过去 30 天）

mmm ssss 2012-1-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/26753-calculation-of-mean-standard-deviation-and-average-for-each-pixel-in-an-image-m-n

if i have an image M*N

if i want to making each pixel in the center of window with 31*31 size , and then compute the average and standard deviation and the mean based on pixel 's nighborhoods ? how this can be done?

i dont mean computing the mean , standard deviation , and average for the whole image?

i wait any help

回答（2 个）

Teja Muppirala 2012-1-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/26753-calculation-of-mean-standard-deviation-and-average-for-each-pixel-in-an-image-m-n#answer_34893

If you have the Image Processing Toolbox, the functions

IMFILTER (can be used to do mean filtering on a neighborhood),

STDFILT (standard deviation on a neighborhood),

or the more general NLFILTER (arbitrary function on a neighborhood),

are there to do these types of operations quite easily.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

David Young 2012-1-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/26753-calculation-of-mean-standard-deviation-and-average-for-each-pixel-in-an-image-m-n#answer_34854

在 MATLAB Online 中打开

To get the means, you can do

means = conv2(Image, ones(31)/(31*31), 'valid');

Note that means(1,1) is the mean for the window centred on Image(16,16), and so on.

I'm not sure how the average is different from the mean.

To get the SDs, just extend the technique above in the obvious way, using the standard formula for the SD.

It's true that I haven't told you how to compute the neighbourhood SDs, but once you understand how the neighbourhood means are computed I am sure you'll be able to see how to get the SDs - you just need to apply the same technique to the pointwise square of the image and look up the formula for the SD.

David Young 2012-1-25