eval_mi_cps_warp(kate)

 EVAL_MI_CPS_WARP: get similarity score between CPS warped image and
                    reference. (Evaluate the clamped-plate spline warp using
                    mean-squared-difference)

 Code written by Katherine Smith, 2003

    GENERAL

      score = eval_msd_cps_warp(params, start_points_vec, ref_image_vec)

    INPUT/S

      -params:
           The paramters of the warps.

           params(1): warp centre
           params(2): r
           params(3): d

      -warp centre:
           Not in parameters already??

      -r:
           Not in parameters already??

      -start_points_vec:
           Points before CPS warp.

      -start_image_vec:
           Image before CPS warp.

      -ref_image_vec:
           The reference image to be compared to.
           
    OUTPUT/S

      -score:
           The similarity score w.r.t. the reference image. 
           (Mutual information)

    PENDING WORK

      -

    KNOWN BUG/S

      -None.

    COMMENT/S

      -

    RELATED FUNCTION/S

      LINEAR_WARP, MSD, EVAL_MSD, 
      EVAL_MODEL_MULTI_WARP

    ABOUT

      -Created:     November 23rd, 2003
      -Last update: Novermber 27th, 2003
      -Revision:    0.0.4
      -Author:      R. S. Schestowitz, University of Manchester
 ==============================================================

0001 function score = eval_mi_cps_warp(params, warp_centre, r, start_points_vec, start_image_vec, ref_image_vec)
0002 % EVAL_MI_CPS_WARP: get similarity score between CPS warped image and
0003 %                    reference. (Evaluate the clamped-plate spline warp using
0004 %                    mean-squared-difference)
0005 %
0006 % Code written by Katherine Smith, 2003
0007 %
0008 %    GENERAL
0009 %
0010 %      score = eval_msd_cps_warp(params, start_points_vec, ref_image_vec)
0011 %
0012 %    INPUT/S
0013 %
0014 %      -params:
0015 %           The paramters of the warps.
0016 %
0017 %           params(1): warp centre
0018 %           params(2): r
0019 %           params(3): d
0020 %
0021 %      -warp centre:
0022 %           Not in parameters already??
0023 %
0024 %      -r:
0025 %           Not in parameters already??
0026 %
0027 %      -start_points_vec:
0028 %           Points before CPS warp.
0029 %
0030 %      -start_image_vec:
0031 %           Image before CPS warp.
0032 %
0033 %      -ref_image_vec:
0034 %           The reference image to be compared to.
0035 %
0036 %    OUTPUT/S
0037 %
0038 %      -score:
0039 %           The similarity score w.r.t. the reference image.
0040 %           (Mutual information)
0041 %
0042 %    PENDING WORK
0043 %
0044 %      -
0045 %
0046 %    KNOWN BUG/S
0047 %
0048 %      -None.
0049 %
0050 %    COMMENT/S
0051 %
0052 %      -
0053 %
0054 %    RELATED FUNCTION/S
0055 %
0056 %      LINEAR_WARP, MSD, EVAL_MSD,
0057 %      EVAL_MODEL_MULTI_WARP
0058 %
0059 %    ABOUT
0060 %
0061 %      -Created:     November 23rd, 2003
0062 %      -Last update: Novermber 27th, 2003
0063 %      -Revision:    0.0.4
0064 %      -Author:      R. S. Schestowitz, University of Manchester
0065 % ==============================================================
0066 
0067 % warp_centre = params(1);
0068 % r = params(1);
0069 d = params(1);
0070 
0071 % rescale
0072 
0073 % normalise params to 1
0074 
0075 max_d = 0.67;
0076 
0077 %scaled_d = d/r;
0078 
0079 if ((abs(d) > max_d) | ((warp_centre-r <0) | (warp_centre+r > max(start_points_vec))))
0080 
0081      % if any of the parameters is not between -0.67
0082      %and 0.67, or the warp's location or size is invalid
0083   score = size(start_points_vec,1); % set to number of points???
0084 else 
0085      % if okay
0086   warped_points = cps_warp_1d(start_points_vec,warp_centre,r,d); 
0087      % apply warp
0088   warped_image = interp1(start_points_vec,start_image_vec,warped_points, 'linear',0);
0089      % interpolate to create warped image from the warped points
0090   score = mi(ref_image_vec, warped_image, 256); 
0091      % score acc to mutual information measure (entropy)
0092 end
0093 params 
0094      % display parameters and score (still under debugging??)
0095 score