# Finding value of a matrix

1 view (last 30 days)
FIR on 19 Dec 2012
I have a 3x3 matrix, for example:
d=rand(3,3)
Now i want to implement the equation
V=1/2(d(q4,q5)+d(q5,q6))
where q5 is the centre pixel
q4,46 are neighbouring pixels
for example
d= q1 q2 q3
q4 q5 q6
q7 q8 q9
Walter Roberson on 19 Dec 2012
q4 and q5 and so on are values of those pixels?

Walter Roberson on 19 Dec 2012
Hard to tell. You might be asking for
oldMatrix = double(ImageMatrix);
NewMatrix = ( oldMatrix(:,1:end-1) + oldMatrix(:,2:end) ) ./ 2;
But perhaps your "d" matrix is trying to talk about weighting the pixel values ? If so then let w1 be the weight for what you showed as d(q4,q5), and let w2 be the weight for what you showe as d(q5,q6), and then
NewMatrix = ( w1 .* oldMatrix(:,1:end-1) + w2 .* oldMatrix(:,2:end) ) ./ 2;
Walter Roberson on 19 Dec 2012
B(i,j)=median(K(:));

Muruganandham Subramanian on 19 Dec 2012
Edited: Muruganandham Subramanian on 19 Dec 2012
d=ones(3);
V=1/2*(d(d(2,2),d(2,2))+d(d(2,2),d(2,3)))
but, If you're using rand(), d(2,2),etc.. can't be accessible, if not using ceil() or floor()..Is this you want?
Muruganandham Subramanian on 19 Dec 2012
@FIR, I din't worked on images, anyway, by using imread() read your image and do the calculation

Image Analyst on 19 Dec 2012
By chance do you mean just convolution with a [1 2 1]/4 kernel, where you take the average of the left pair of pixels and the right pair of pixels? If so, you'd need to extract each color plane first and then use conv2() to get the output image one color plane at a time.

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