InSPIRE utility to resample an 3D image with multi-grid resolution

This program resamples a 3D image. It makes the grid finer or coarser using user designated 'factor'

This is useful for multi-grid image registration to improve accuracy and efficiency. Note in the example with phantom, users can see the more pixelated figure with the coarser grid. IMPORTANT REMINDER NOTE: for meshgrid implementation in Matlab, meshgrid(a,b,c) means there will be a columns, b rows and c pages. Therefore put if user need to create n column, put 'ncol' in the 'a' position, and 'nrow' in 'b' position, and 'npage' as expected in the 'c' position. See documentation in code.