I need code urgently for my project to find average of pixels by considering 7 by 7 matrix

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viswanath reddy 2019-1-28

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回答： Image Analyst 2019-1-28

I want code for finding the mean by considering 7 by 7 matrix. For each pixel in the image i want to calculate 5 mean values. First mean should be calculated by placing the original pixel at the center of 7 by 7 matrix and the second,third,fourth and fifth mean should be calculated by placing the same pixel at top left,top right,bottom left,bottom right of the 7 by 7 matrix.

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Addy 2019-1-28

Check if this answer works:

https://www.mathworks.com/matlabcentral/answers/272994-calculate-average-around-pixel

Jan 2019-1-28

What have you tried so far? What is your question?

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Answer 1

Walter Roberson 2019-1-28

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Use filter2()

The mask you pass to filter2 is applied with the pixel at the top left if I remember correctly. However can ask for the full results rather than 'valid' and you can extract subsets of the filtered results . MM(1:end-6,1:end-6), MM(7:end,1:end-6) and so on where MM is the output of filter2 .

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viswanath reddy 2019-1-28

I need to calculate 5 mean values of every pixel in an image. The first mean value should be calculated by assuming the pixel at the center of 7*7 window and the 2nd,3rd,4th and 5th mean values should be calculated by assuming that the same pixel is located at top left,top right,bottom left and bottom right corners of the 7*7 window.

Walter Roberson 2019-1-28

you already said that in the same words. If I did not understand your question then you need to explain differently such as with an example .

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Answer 2

Image Analyst 2019-1-28

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在 MATLAB Online 中打开

Try this:

grayImage = imread('moon.tif'); % Whatever ...
% Shift pixel at upper left to middle.
kernel = zeros(7);
kernel(1,1) = 1;
upperLeft = imfilter(grayImage, kernel);
% imshow(upperLeft);
% Shift pixel at upper right to middle.
kernel = zeros(7);
kernel(1,3) = 1;
upperRight = imfilter(grayImage, kernel);
% imshow(upperRight);
% Shift pixel at lower left to middle.
kernel = zeros(7);
kernel(3,1) = 1;
lowerLeft = imfilter(grayImage, kernel);
% imshow(lowerLeft);
% Shift pixel at lower right to middle.
kernel = zeros(7);
kernel(3,3) = 1;
lowerRight = imfilter(grayImage, kernel);
% imshow(lowerRight);

But it's not really correct to call the pixel at the upper left of a 7x7 window a "mean" since it's just a single pixe,, not the average of multiple values.