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.
