how can I reshape and display all the images from matrix

Hi I have a matrix 16896x1536 double this matrix contains of 33 color images of size 512x512. I used the code below to reshape and display all the images but I have this error

Error using reshape To RESHAPE the number of elements must not change.

This is my code

    figure
  colormap(gray)
  for i = 1:33
  subplot(5,5,i)
  digit = reshape(a(i, 2:end), [28,28])';
  imagesc(digit)
  title(num2str(a(i, 1)))
  end

[Rik]

Have you even thought of reading the documentation? I don't understand how people can use a function, get an error, and then ask a question here before reading the documentation. The error message already gives you the answer: you cant change the shape (reshape) a matrix and change the number of elements at the same time.

How exactly does the master matrix contain your images? I would advise you to convert it to a 512x512xcolorximage sized matrix. Then your code will be much more clear.

Answer 1

[Guillaume]

I have absolutely no idea why you're trying to reshape something into a 28x28 matrix in your loop, nor why you iterating for 1 to 33 when you tell us your input 16896x1536.

Assuming that your extremely badly named a is your 16896x1536 matrix, this may work:

stackedimages = reshape(a, 512, 512, 3, 33);

You may have to permute the order of the 512s, 3 and 33 as you've not stated how the images are arranged into your wrongly shaped matrix. Once it is correct:

for imageindex = 1:33
   subplot(5, 7, imageindex)  %note that 5x5 is only room for 25 images, so using 5x7)
   digit = stackedimage(:, :, :, imageindex);  %depending on the permutation imageindex may be 1st, 2nd, 3rd or 4th dimension
   imagesc(digit);
   title(sprintf('image %d', imageindex));
end