InSPIRE utility to smooth 3D volume data

This is a program to test how a 1D gaussian filter can be used to smooth a set of 3-D data.

This example uses a gaussian filter extracted from wikipedia:
kernel = [0.125 0.625 1 0.625 0.125] for standard normal distribution. Note that given this kernel, users at least need to pad two layers of zeros around the a3d, otherwise there will be out of bound error when the edge voxels of a3d are being processed. This filter could be used to compare with the convn function in matlab, but it may give you an intuitive control of your filtering.