MATLAB: Sliding window operation in image

image processingImage Processing Toolboxkernel

I have an image of size 256*256, i want to use 3*3 window which slides over image and change the value of central pixel as sum of neighbouring 8 pixels. Please Help.

Best Answer

Try conv2(), imfilter(), nlfilter(), or, if you want to move in "jumps" instead of by one pixel, blockproc().

Related Solutions

MATLAB: Can any one explain me the concept of conv2(), nfilter in sliding withdow

nlfilter() slides the window across the image and applies some custom function, that you supply, to the pixels in the window. nlfilter can apply some custom function to the pixels in the window, something that conv2() cannot do.

conv2() slides the window across the image and multiplies the pixels in the window by the pixels in the filter kernel window and sums them. The output pixel is the sum. conv2() does not apply some custom function like nlfilter can.

MATLAB: Why the error is coming

who is x?

That message is the result of trying to access an non-existent element of the array, such as x(0).

Make sure x has the right size.

By the way, your for-loop code

x= rand(3,4); % sample data
[M,N]=size(x); 
y=zeros(1,N); 
for l=1:N
    sum1=sum(x(:,l).*log(x(:,l)));
    sum1=-1*sum1; 
    y(1,l)=sum1; 
end

Is the same that this, in a single line:

for l=1:N
    y(l) = -( sum(x(:,l).*log(x(:,l))) );
end

Best Answer

Related Solutions

MATLAB: Can any one explain me the concept of conv2(), nfilter in sliding withdow

MATLAB: Why the error is coming

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