How to store number of images matrix and double values in cell or array?

I am not to familiar with arrays or cells in MATLAB. I would like to make an array that contains in one cell for image 1, image 2, image 3 etc the following per image;

Image Matrix (Pixel value (n x m size) matrix of image) - M
string value - imageType
double value - pos
double value - exposure

How do I do this?

It should be mentioned I will use the values above (matrix and the values) for calculations like sum and so forth etc.

Also, how do I sort them in decreasing order of pos value so that the others also are sorted accordingly?

Answer 1

[David Young]

Cell arrays could be used, but this looks like an ideal case for a struct array. See this introduction. You might do something like this:

for imageNumber = 1:numberOfImages
  <read in or compute the current image and its associated data to the variables 
     M, imageType, pos and exposure>
  imageStruct(imageNumber).imageMatrix = M;
  imageStruct(imageNumber).imageType = imageType;
  imageStruct(imageNumber).pos = pos;
  imageStruct(imageNumber).exposure = exposure;
end

Then to sort, something like this:

[~, sortedIndices] = sort([imageStruct.pos], 2, 'descend');
imageStruct = imageStruct(sortedIndices);

which will keep each image with its associated data in the sorted array.

[Image Analyst]

I agree that a struct array is better and much simpler to understand. That said, the FAQ has a good discussion of cell arrays that should help you get a good intuitive feeling for them http://matlab.wikia.com/wiki/FAQ#Can_you_program_up_the_algorithm_in_this_article_for_me_and_explain_it_to_me.3F>, but again, I recommend David's approach.