How to crop arrays using a vector? (reverse of padarray)

*Short version: I'm looking for the reverse of padarray, where you can do padarray(a,[2 2 2]), but instead have it crop [2 2 2] instead of pad [2 2 2]. (Or alternatively, imcrop for more then two dimensions); *

Long version: I have a cell arrays of unknown size K, each cell in the array contains an numerical array with dimensions (m,n,k,... )importantly:

          1. I don't know beforehand how many dimensions there will be for the 
             numerical arrays in the different cell arrays, but I
             know that within a cell array all the numerical arrays will have 
             the same number of dimensions. 

          2. While all the arrays have the same number of dimensions, they 
             differ in size. 

Basically I want to make a functions that crops the numerical arrays to the smallest dimensions, and then concatenates them, i.e. if

      a{1} = zeros(10,10)
      a{2} = zeros(16,6)
      a{3} = zeros(6,6)

I want the outcome to be an array c with size (6,6,3).

I guess the problem is that I don't know how to index the arrays for a variable amount of dimensions. That is, I can get the size to which I need to crop (or the number by which I need to crop) in vector form like [6 6] or [15 4 8], but I don't know how to use this vector to index my arrays.

Thanks in advance!

Edit: Just thought of something, but it's very ugly: if we know we want to crop to an array of size (30,30,30)

minSize = [30 30 30]
c = []

for ii = length(a);
  temp = a{ii}(:);

    mask = zeros(minSize)
    padding = (minSize - size(a{ii})./2;
    mask = padarray(mask,padding,1,'both');
    mask = logical(mask);
    temp(mask)= [];

    temp = reshape(temp,minSize);
    c = cat(ndim(a{ii})+1,c,temp);
  end