Resize image array

Fast downsampling of the first two dimensions in a multi-dimensional array

Function to downsample an image stack based on averaging through a symmetric box filter in the first two dimensions. This is comparable to using other code such as imresize(DataIn,bin,'box') in a for loop but will perform much faster.
It will resize only the first two dimensions of any given data matrix while leaving additional dimension unchanged.
Usage: DataOut = arrayResize(DataIn,bin)
DataIn = x*y*n matrix to be downsampled.
bin = size of the box filter.
Downsampled image stack consists of averages of squares of the size bin*bin in the x and y dimension. If dimension x or y can not be divided by bin, the downsampled matrix will not contain the lower and right edges of DataIn that are above the highest divider.