How do I divide an image into blocks for processing?

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baran 2011-2-14

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评论： Image Analyst 2016-8-5

I am new to MATLAB.

I am trying to write code which will divide the image in nonoverlaping blocks of size 3*3. I am supposed to do operations on specific blocks like getting the value of the center pixel of block and do some operations.

I don't know where to start. Using command like blockproc wont help. Can anyone suggest a start point?

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Aparna RAJAWAT 2016-8-5

I want to divide an image into different block size.and image size is 16x16.block size are 4x4,5x5 and so on.please help me how to do coding in matlab

Image Analyst 2016-8-5

Aparna, please see the FAQ

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回答（2 个）

Yaw 2011-2-17

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The best way to do this is to use the "mat2cell" command. It's very simple.

a=3; b=3; %window size
x=size(f,1)/a; y=size(f,2)/b; %f is the original image
m=a*ones(1,x); n=b*ones(1,y);
I=mat2cell(f,m,n);

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Walter Roberson 2011-2-17

blockproc() is able to handle situations where the original matrix does not happen to have dimensions that are multiples of 3. Your code will crash on those cases.

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Vieniava 2011-2-14

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在 MATLAB Online 中打开

Suppose I is your image matrix. Trivial way is shown below:

s=size(I);
wing=1;         % ;)
bs=2*wing+1;      % block size
for i=wing: bs : (s(1)-wing)
  for j=wing : bs : (s(2)-wing)
       BLOCK=I( (i-wing):(i+wing) , (j-wing):(j+wing) );
       %
       % paste your function/code  which processes the BLOCK
       %
    end
  end