how to get odd rows and columns,even rows and columns

A1 is the lena image

A is to the first row

similarly how to get the even rows ,even columns,odd rows,odd columns

 A1 = imread('lena1.jpg');
  A=A1(:,1);

[juveria fatima]

 A=A1(:,1);  its is giving on 1 row to entire image

similarly i want to get all the rows one by one indivudually

can any one help using loops

[Birdman]

No need for loops again:

A1(1:end,:)

[juveria fatima]

i want to store all the rows one by one

i am finding the probability of each row one by one similarly each column one by one

(sum of probabilities should be one)

here is my code

%A = randi(255, [1 10]);
% A = imread('lena1.jpg');

   A1 = imread('lena1.jpg');
    A=A1(:,1);

A = reshape(uint8(A), [1 512*1]);
s = size(A);

[rows columns numberOfColorBands] = size(A);

col1 = 1;
col2 = floor(columns/2);
col3 = col2 + 1;
row1 = 1;
row2 = floor(rows/2);
row3 = row2 + 1;
% Now crop
upperLeft = imcrop(A, [col1 row1 col2 row2])

count = zeros(1,256);
for i =1:s(1)
    for j =1:s(2)
        count(uint8(A(i,j)+1)) = count(uint8(A(i,j)+1))+1;
    end
end

count = double(count) /(512*1);
sumofprob=sum((count))
plot(count)

Answer 1

[Birdman]

Consider you have number of rows and columns which is an even number,

Odd rows:

A1(1:2:end-1,:)

Even rows:

A1(2:2:end,:)

Odd columns:

A1(:,1:2:end-1)

Even columns:

A1(:,2:2:end)

[juveria fatima]

thank you

[Jos (10584)]

By substracting one, you discard the last odd row (column) when the number of rows (columns) of the array is odd. When this number is even, it does not matter, so just to be flexible, do not subtract one :)

[Birdman]

Yes you are right Jos, therefore at the beginning of the question, I stated that:

Consider you have number of rows and columns which is an even number

:)