svn co https://svn.janelia.org/penglab/projects/vaa3d/trunk/released_plugins/v3d_plugins/ssd_registration

   Usage: v3d -x imagereg.dylib -f rigidreg -o <output_warped_image> -p 
                                   "#t <template.img> #ct <refchannel_template> #s <source.img> #cs <refchannel_source> 
                                  [#ds <downsample_ratio> #n <max_iters> #m <step_inimultiplyfactor> 
                                   #a <step_annealing_rate> #ms <min_step>]"