How to save image stacks to a .mat file that is readable

Hi,

I have 20 images that are being stacked (512x512x20) where all the information is in gray scale intensities, and I want the actual data saved into a .mat file. But the file it should be writing into is blank (absolutely no text or numbers). How can I accomplish this as this is pre-processing for a different program? My input file format is a 262144x2 matrix, where I only want the second column of information. I know the stack is being created correctly because I can use the implay function ( implay(ImageStack) ) and see the images.

The file written is as follows (after several prompts of FileSave, i, and j):

ImageStack = zeros(512,512,j-i);  %%initiates image stack 

FS = fopen(FileSave,'a+');        %%open file for writing 

for k = i:j                                     

      FileName = ['BC_' num2str(k) '_1.txt'];     %%open textfile                      
      A = load (FileName);                        %%load file to matrix A
      B = A(:,2);                                %%Takes only one column from Matrix A into Matrix B
      C = reshape(B,512,512)';                    %%reshapes Matrix B (262144x1) to Matrix C (512x512)
      I = mat2gray(C);                            %%converts pixel intensity to grays cale (0-1)
      ImageStack(:,:,k) = I;                      %%places image into to stack     
      fwrite(FS,ImageStack);                      %%saves file for reading
  end

I've tried the save function, but it only saves the variables (i,j,FileName, etc..) Not the actual data within the files. How do I save the actual data to a .mat file? The file File specified is blank after save; and after using the save function it only returns the variables, not the data. I'm using version R2014a.

Thanks

Answer 1

[Image Analyst]

Get rid of the fopen() and fwrite(). Just use save():

After your for loop (where you create ImageStack), just write ImageStack out all in one line:

fullFileName = fullfile(folder, 'ImageStack.mat');
save(fullFileName, 'ImageStack'); 
% Note: save() overwrites/destroys any existing file (does not "add/append").

[Eric]

Excellent! Thank you very much. I see what I was doing wrong.