convert image matrix to row vector

i have an image size 256x256 and i want to Convert the image matrix to a row vector with length same size , how i can got it please?

[DGM]

What exactly do you mean by "length of same size". Length isn't size.

You can use reshape() to reshape the array, but it will be [1 65536].

A=reshape(A',1,[]); % if you want rows

If you're expecting a [1 256] vector, then you'll have to decide how exactly you want to reduce the image conceptually (e.g. maybe you want directional mean or min or max; maybe you just want to extract a single row from the image)

[Samaa Yasser]

first thank you for your help..

i want to generate a row vector from image pixel.

so i want to calculate the total number of the original image pixels first, then Convert the image matrix of size MN for example to a row vector with length NM , inorder to get random permutation of this row vector, so can you help

Answer 1

[David Hill]

yourMatrix(:)';

[Samaa Yasser]

thank you so much

Answer 2

[DGM]

Consider a 3x3 test image:

A=repmat(1:3,[3 1])
A =
     1     2     3
     1     2     3
     1     2     3

The line I suggested:

A=reshape(A',1,[]); % if you want to sample from rows

will take the rows of A and end-concatenate them into one long row vector of size 1x9. No need to calculate numel(A).

A =
     1     2     3     1     2     3     1     2     3

If instead you were to do

A=reshape(A,1,[]); % if you want to sample from cols

or

A=A(:)'; % David's suggestion 

you would still get the same output size, but you would be sampling columnwise instead.

ans =
     1     1     1     2     2     2     3     3     3

If the ordering of the pixels doesn't matter, you could do it either way.

[Samaa Yasser]

thaaank you sooo much i really apperciate =)