How to write code for 3x3 sliding window to process over a Image with Pixel size of 256x256

1. Choose the first pixel. Having it as the center pixel i have to form a 3x3 window. [Being the first pixel i've padded the Matrix with Zeros]

2. If that center Pixel is Noise Pixel it's location should be returned with all its neighborhood pixels. I will convert this 3x3 Matrix into a 1-D array and do my calculations to correct the corrupted pixels.

Here i'm struggling in designing the sliding 3x3 window to move over the image

Answer 1

[Rushi Vyas]

Hi Manoja,

I understand you want to perform a 3x3 sliding window operation on a padded image. When you encounter noise, you want to flatten the 3x3 matrix and perform corrections.

The below code performs this operation:

%A is your image
  
B = padarray(A,[1 1]);
for i = 2:m-1
    for j = 2:n-1
        if mod(B(i,j), 10) == 0 %corrupt pixel condition
            mat = B(i-1:i+1,j-1:j+1); % selecting your 3x3 window
            arr = reshape(mat, [1 numel(mat)]); %convert to 1-D array
            B(i,j) = sum(arr);%replaced with corrections
        end
    end
end
  

[Manoja YK]

Thank you very much sir. Your answer is accurate