Accessing elements of a block

Please help me soon with this! Thanks a ton!

I need to divide an image of size 72x72 into 64 blocks of size 9x9 each. Then, I need to perform some sort of processing on each block by accessing each value within each block. Should I use blockproc or mat2cell? How do I access each element within a block? If I use blockproc, how do I use the third parameter to create my own function that will be called for each block?

The following code threw this error

??? Cell contents reference from a non-cell array object.

Error in ==> module2 at 21 x=myCell{1,1}{j,k};

[final_img]=module1;

myCell = mat2cell(final_img,[9 9 9 9 9 9 9 9], [9 9 9 9 9 9 9 9]);
% C={myCell};
y=1;    %initial previous value
w=1;
o=1;    %o-output vector index
p=1;
rx = zeros(64,1);
ry = zeros(64,1);
rx(1)=0;
ry(1)=0;

for i=1:8
    for l=1:8
        [m,n]=size(myCell{1,1}); %m-rows n-column m=n=9

              for j=1:m        
                  for k=1:n
                      x=myCell{1,1}{j,k};
                      z=myCell{1,1}{k,j};
                          if x~=y %compare with previous value
                              rx(o)=rx(o)+1; %horizontalcount++ 
                          end
                          if z~=w
                              ry(p)=ry(p)+1; %verticalcount++
                          end
                      y=x;
                      w=z;
                  end
              end
      end
    o=o+1;
    p=p+1;
  end

So, how do I get the value of x and z?

Answer 1

[Walter Roberson]

All of your myCell{1,1} should instead be myCell{i,l} and the indexing after that should be in () instead of in {}

myCell{i,l}(j,k)

[Monisha]

Thank you :)

The thing is I have to find out how many times 0 changes to 1 and vice-versa (since its a binary image) and use a count variable to do that. Is the code implementing this logic, do you think? I'm getting very weird values!

My rx array of size 64x1 contains 34, 46, 46, 48, 50, 36, 40, 24 and then the rest are zeros.

My ry array also of size 64x1 contains 60, 38, 22, 16, 8, 4, 8, 18 and then zeros.

[Walter Roberson]

Your "y" and "w" do not change at all, so you are not comparing against the "previous" values, only against fixed values.

[Monisha]

wait! wait! I think I found the error...

the incrementing of the variables o and p have been put in the wrong place! It works now!

So the code looks like this now. Are you sure abt the y and w not changing on each iteration?

[final_img]=module1;

myCell = mat2cell(final_img,[9 9 9 9 9 9 9 9], [9 9 9 9 9 9 9 9]);

y=1; %initial previous value

w=1;

o=1; %o-output vector index

p=1;

rx = zeros(64,1);

ry = zeros(64,1);

rx(1)=0;

ry(1)=0;

for i=1:8

for l=1:8

[m,n]=size(myCell{i,l}); %m-rows n-column m=n=9

for j=1:m

for k=1:n

x=myCell{i,l}(j,k);

z=myCell{i,l}(k,j);

if x~=y %compare with previous value

rx(o)=rx(o)+1; %horizontalcount++

end

if z~=w

ry(p)=ry(p)+1; %verticalcount++

end

y=x;

w=z;

end

end

o=o+1;

p=p+1;

end

end