time_smooth_prior

 TIME_SMOOTH_PRIOR calculate image prior
 Reg= time_smooth_prior( inv_model )
 Reg        => output regularization term
 inv_model  => inverse model struct
 inv_model.time_smooth_prior.space_prior =
          @space_prior_function
 inv_model.time_smooth_prior.time_steps  =
          # of steps into future and past
 inv_model.time_smooth_prior.time_weight =  0..1
    each step is weighted by time_weight^time_difference

 This image prior is intended to be used as
  R'*R, but may be used as R for as well.

 The time smoothing prior penalizes non-smooth
 contributions in spatial and time directions

 The function of Reg is ||x-x_0||_Reg where 
 x is the image at 2*n+1 time slices concatenated
 vertially. x= [x_{j-n}; ... ; x_j ; ... x_{j+n} ]

 On a finite element mesh, we define the it as 
 -1 for each adjacent element, and 3 (in 2D) or 4 (in 3D)
 for the element itself

0001 function Reg= time_smooth_prior( inv_model );
0002 % TIME_SMOOTH_PRIOR calculate image prior
0003 % Reg= time_smooth_prior( inv_model )
0004 % Reg        => output regularization term
0005 % inv_model  => inverse model struct
0006 % inv_model.time_smooth_prior.space_prior =
0007 %          @space_prior_function
0008 % inv_model.time_smooth_prior.time_steps  =
0009 %          # of steps into future and past
0010 % inv_model.time_smooth_prior.time_weight =  0..1
0011 %    each step is weighted by time_weight^time_difference
0012 %
0013 % This image prior is intended to be used as
0014 %  R'*R, but may be used as R for as well.
0015 %
0016 % The time smoothing prior penalizes non-smooth
0017 % contributions in spatial and time directions
0018 %
0019 % The function of Reg is ||x-x_0||_Reg where
0020 % x is the image at 2*n+1 time slices concatenated
0021 % vertially. x= [x_{j-n}; ... ; x_j ; ... x_{j+n} ]
0022 %
0023 % On a finite element mesh, we define the it as
0024 % -1 for each adjacent element, and 3 (in 2D) or 4 (in 3D)
0025 % for the element itself
0026 
0027 % (C) 2006 Andy Adler. License: GPL version 2 or version 3
0028 % $Id: time_smooth_prior.m 3289 2012-07-01 10:40:31Z aadler $
0029 
0030 warning('EIDORS:deprecated','TIME_SMOOTH_PRIOR is deprecated as of 08-Jun-2012. Use PRIOR_TIME_SMOOTH instead.');
0031 
0032 if isfield(inv_model,'time_smooth_prior');
0033   inv_model.prior_time_smooth = inv_model.time_smooth_prior;
0034 end
0035 
0036 Reg = prior_time_smooth( inv_model);