int
main(int argc, char *argv[])
{
  char        **av, *in_vol, *out_vol;
  int         ac, nargs;

  MRI         *mri_in, *mri_out, *mri_tmp ;
  LTA         *lta = 0;
  MATRIX *i_to_r_src = 0; /* src geometry of the input LTA */
  MATRIX *V_to_V = 0; /* Final voxel-to-voxel transform */
  MATRIX *r_to_i_dst = 0; /* dst geometry of the input LTA */
  MATRIX *m_tmp = 0;
  MATRIX *i_to_r_reg = 0; /* i_to_r of the volume after registration */
  MATRIX *r_to_i_out = 0; /* r_to_i of the final output volume */
  VOL_GEOM vgm_in;
  int x, y, z;
  double maxV, minV, value;
  //  MATRIX *i_to_r, *r_to_i;

  /* rkt: check for and handle version tag */
  nargs = handle_version_option (argc, argv, "$Id: mri_transform_to_COR.c,v 1.8 2011/03/02 00:04:55 nicks Exp $", "$Name: stable5 $");
  if (nargs && argc - nargs == 1)
    usage_exit (0);
  argc -= nargs;

  Progname = argv[0] ;
  ErrorInit(NULL, NULL, NULL) ;
  DiagInit(NULL, NULL, NULL) ;

  ac = argc ;
  av = argv ;
  for ( ; argc > 1 && ISOPTION(*argv[1]) ; argc--, argv++)
  {
    nargs = get_option(argc, argv) ;
    argc -= nargs ;
    argv += nargs ;
  }

  if (argc < 3)
    usage_exit(0) ;

  in_vol = argv[1] ;
  out_vol = argv[2] ;

  printf("reading volume from %s...\n", in_vol) ;
  mri_in = MRIread(in_vol) ;
  if (!mri_in)
    ErrorExit(ERROR_NOFILE, "%s: could not read MRI volume %s", Progname,
              in_vol) ;

  /* Convert mri_in to float type */
  /* double would be more accurate */
  if (mri_in->type != MRI_FLOAT)
  {
    printf("Input volume type is %d\n", mri_in->type);
    printf("Change input volume to float type for convenience and accuracy");
    mri_tmp = MRIchangeType(mri_in, MRI_FLOAT, 0, 1.0, 1);
    MRIfree(&mri_in);
    mri_in = mri_tmp; //swap
  }

  /* Get input volume geometry, which is needed to compute i_to_r
   * and r_to_i of input volume. Note that i_to_r and r_to_i assumed
   * a certain prespecified c_r, c_a, c_s
   */
  getVolGeom(mri_in, &vgm_in);

  maxV = -10000.0;
  minV = 10000.0;
  for (z=0; z < mri_in->depth; z++)
    for (y=0; y< mri_in->height; y++)
      for (x=0; x < mri_in->width; x++)
      {
        if (MRIFvox(mri_in, x, y, z) > maxV )
          maxV = MRIFvox(mri_in, x, y,z) ;
        if (MRIFvox(mri_in, x, y, z) < minV )
          minV = MRIFvox(mri_in, x, y,z) ;
      }

  printf("Input volume has max = %g, min =%g\n", maxV, minV);

  printf("Scale input volume by %g \n", scale);

  maxV = -10000.0;
  minV = 10000.0;
  for (z=0; z < mri_in->depth; z++)
    for (y=0; y< mri_in->height; y++)
      for (x=0; x < mri_in->width; x++)
      {
        MRIFvox(mri_in, x, y, z) *= scale;
        if (MRIFvox(mri_in, x, y, z) > maxV )
          maxV = MRIFvox(mri_in, x, y,z) ;
        if (MRIFvox(mri_in, x, y, z) < minV )
          minV = MRIFvox(mri_in, x, y,z) ;
      }

  printf("Input volume after scaling has max = %g, min =%g\n", maxV, minV);

  /* Try to compute the Voxel_to_Voxel transform from the input volume
   * and the registration target/reference volume!
   * If no registration is involved, vox_to_vox is simply identity
   */
  /* Things become more complicated when allowing inverse transform */
  if (transform_flag)
  {
    int transform_type;

    printf("INFO: Applying transformation from file %s...\n",
           transform_fname);
    transform_type =  TransformFileNameType(transform_fname);

    /* Read in LTA transform file name */
    if (transform_type == MNI_TRANSFORM_TYPE ||
        transform_type == TRANSFORM_ARRAY_TYPE ||
        transform_type == REGISTER_DAT ||
        transform_type == FSLREG_TYPE
       )
    {

      printf("Reading transform ...\n");
      lta = LTAreadEx(transform_fname) ;

      if (!lta)
        ErrorExit(ERROR_NOFILE, "%s: could not read transform file %s",
                  Progname, transform_fname) ;

      if (transform_type == FSLREG_TYPE)
      {
        if (lta_src == 0 || lta_dst == 0)
        {
          fprintf(stderr, "ERROR: fslmat does not have information on the src and dst volumes\n");
          fprintf(stderr, "ERROR: you must give options '-src' and '-dst' to specify the src and dst volume infos for the registration\n");
        }


        LTAmodifySrcDstGeom(lta, lta_src, lta_dst); // add src and dst information
        //The following is necessary to interpret FSLMAT correctly!!!
        LTAchangeType(lta, LINEAR_VOX_TO_VOX);
      }
      if (lta->xforms[0].src.valid == 0)
      {
        if (lta_src == 0)
        {
          fprintf(stderr, "The transform does not have the valid src volume info.\n");
          fprintf(stderr, "Either you give src volume info by option -src or\n");
          fprintf(stderr, "make the transform to have the valid src info.\n");
          ErrorExit(ERROR_BAD_PARM, "Bailing out...\n");
        }
        else
        {
          LTAmodifySrcDstGeom(lta, lta_src, NULL); // add src information
        }
      }
      if (lta->xforms[0].dst.valid == 0)
      {
        if (lta_dst == 0)
        {
          fprintf(stderr, "The transform does not have the valid dst volume info.\n");
          fprintf(stderr, "Either you give src volume info by option -dst or\n");
          fprintf(stderr, "make the transform to have the valid dst info.\n");
          fprintf(stderr, "If the dst was average_305, then you can set\n");
          fprintf(stderr, "environmental variable USE_AVERAGE305 true\n");
          fprintf(stderr, "instead.\n");
          ErrorExit(ERROR_BAD_PARM, "Bailing out...\n");
        }
        else
        {
          LTAmodifySrcDstGeom(lta, NULL, lta_dst); // add  dst information
        }
      }


      // The following procedure aims to apply an LTA computed from COR format to a volume in non-COR format, or vice versa, as long as they share the same RAS
      // first change to LINEAR RAS_TO_RAS using old info
      if (lta->type != LINEAR_RAS_TO_RAS)
      {
        LTAchangeType(lta, LINEAR_RAS_TO_RAS);
      }

      // now possiblly reset the src and dst
      if (lta_src != NULL)
      {
        //always trust the user
        LTAmodifySrcDstGeom(lta, lta_src, NULL);
      }
      if (lta_dst != NULL)
      {
        //always trust the user
        LTAmodifySrcDstGeom(lta, NULL, lta_dst);
      }

      if (lta->type == LINEAR_RAS_TO_RAS)
      {
        /* Convert it to VOX_TO_VOX */
        /* VOXELsrc_to_VOXELdst = R2Vdst*R2Rlta*V2Rsrc */
        /* Note whether the input should be identical to src or dst here depends
         * on whether the LTA here is the direct or inverse transform
         */
        i_to_r_src = vg_i_to_r(&lta->xforms[0].src);
        r_to_i_dst = vg_r_to_i(&lta->xforms[0].dst);

        if (!r_to_i_dst || !i_to_r_src)
          ErrorExit(ERROR_BADFILE, "%s: failed to extract volume geometries from input LTA file",Progname);
        m_tmp = MatrixMultiply(lta->xforms[0].m_L, i_to_r_src, NULL);
        V_to_V = MatrixMultiply(r_to_i_dst, m_tmp, NULL);
        MatrixFree(&m_tmp);

        MatrixFree(&i_to_r_src);
        MatrixFree(&r_to_i_dst);
      }
    }
    else
    {
      fprintf(stderr, "unknown transform type in file %s\n",
              transform_fname);
      exit(1);
    }

    if (invert_flag)
    {
      /* Geometry of input volume should match that of the dst of the LTA */
      if (MYvg_isEqual(&lta->xforms[0].dst, &vgm_in) == 0)
      {
        ErrorExit(ERROR_BADFILE, "%s: dst volume of lta doesn't match that of input volume",Progname);
      }

      i_to_r_reg = vg_i_to_r(&lta->xforms[0].src);

      if (!i_to_r_reg)
        ErrorExit(ERROR_BADFILE, "%s: failed to extract i_to_r of registered volume from LTA",Progname);

      m_tmp =  MatrixInverse(V_to_V, NULL);
      if (!m_tmp)
        ErrorExit(ERROR_BADPARM, "%s: transform is singular!", Progname);

      MatrixFree(&V_to_V);
      V_to_V = m_tmp;
    }
    else
    {
      /* Geometry of input volume should match that of the src of the LTA */
      if (MYvg_isEqual(&lta->xforms[0].src, &vgm_in) == 0)
      {
        ErrorExit(ERROR_BADFILE, "%s: src volume of lta doesn't match that of input volume",Progname);
      }

      i_to_r_reg = vg_i_to_r(&lta->xforms[0].dst);

      if (!i_to_r_reg)
        ErrorExit(ERROR_BADFILE, "%s: failed to extract i_to_r of registered volume from LTA",Progname);
    }

  }
  else
  {
    /* No registration transform need be applied */
    V_to_V = MatrixIdentity(4, NULL);
    i_to_r_reg = extract_i_to_r(mri_in);
    if (!i_to_r_reg)
      ErrorExit(ERROR_BADFILE, "%s: failed to extract i_to_r from input volume",Progname);
  }

  /* Now need to find the vox-to-vox transformation between registered volume
   * (or input volume itself if no registration involved) and the output
   * volume, either in COR format or as the out-like volume
   */
  /* Given a volume with a certain i_to_r, we need to compute the necessary
   * vox-to-voxel transform to change its i_to_r to like another volume.
   * The vox-to-vox is equal to R2V(r_to_i)_likevol*i_to_r_current_vol.
   */
  if (out_like_fname)
  {
    mri_tmp = MRIread(out_like_fname) ;
    if (!mri_tmp)
      ErrorExit(ERROR_NOFILE, "%s: could not read template volume from %s",out_like_fname) ;

    /* out_type = mri_tmp->type; */

    /* specify the out-type to float initially so as not to lose accuracy
     * during reslicing, will change type to correct type later.
     */
    mri_out = MRIalloc(mri_tmp->width, mri_tmp->height, mri_tmp->depth, MRI_FLOAT) ;

    MRIcopyHeader(mri_tmp, mri_out) ;
    MRIfree(&mri_tmp);
  }
  else  /* assume output is in COR format */
  {
    mri_out = MRIalloc(256, 256, 256, MRI_FLOAT) ;
    /* out_type = MRI_UCHAR; */

    /* Who says MRIlinearTransformInterp will change the header??
     * I don't think so!
     */
    //E/ set xyzc_ras to coronal ones.. - these'll get zorched
    //by MRIlinearTransformInterp() - copy again later - is there
    //any use in having them here now?  yes, so we can pass mri_out
    //to the ras2vox fns.


    mri_out->imnr0 = 1; /* what's this? */
    mri_out->imnr1 = 256; /* what's this? */
    mri_out->thick = 1.0;
    mri_out->ps = 1.0; /* what's this? */
    mri_out->xsize = mri_out->ysize = mri_out->zsize = 1.0;
    mri_out->xstart = mri_out->ystart = mri_out->zstart = -128.0;
    mri_out->xend = mri_out->yend = mri_out->zend = 128.0;
    mri_out->x_r =-1;
    mri_out->y_r = 0;
    mri_out->z_r = 0;
    mri_out->x_a = 0;
    mri_out->y_a = 0;
    mri_out->z_a = 1;
    mri_out->x_s = 0;
    mri_out->y_s =-1;
    mri_out->z_s = 0;

    /* In this case, the RAS itself is not fully determined, i.e., c_ras.
     * It's quite arbitrary, different values just change the final
     * sitting of the volume inside the RAS system.
     */
    /* NO! The C_RAS has to be set correctly, depending which target
     * volume the previous Vox_to_Vox transformation assumes!
     * When a registration is involved, the target volume is either
     * the src of LTA (direct) or the dst (inverse transform). When
     * just change format, the target volume is the input itself!!
     */
    if (transform_flag)
    {
      if (invert_flag)
      {
        mri_out->c_r = lta->xforms[0].src.c_r;
        mri_out->c_a = lta->xforms[0].src.c_a;
        mri_out->c_s = lta->xforms[0].src.c_s;

      }
      else
      {
        mri_out->c_r = lta->xforms[0].dst.c_r;
        mri_out->c_a = lta->xforms[0].dst.c_a;
        mri_out->c_s = lta->xforms[0].dst.c_s;
      }
    }
    else
    {
      mri_out->c_r = mri_in->c_r;
      mri_out->c_a = mri_in->c_a;
      mri_out->c_s = mri_in->c_s;
    }

    mri_out->ras_good_flag=1; /* What does this flag mean ? */

    /* since output is just transformed input */
    MRIcopyPulseParameters(mri_in, mri_out) ;

  }

  /* Compute the final input-to-output VOX_to_VOX transformation matrix */
  r_to_i_out = extract_r_to_i(mri_out);

  m_tmp = MatrixMultiply(r_to_i_out, i_to_r_reg, NULL);
  V_to_V = MatrixMultiply(m_tmp, V_to_V, V_to_V);
  MatrixFree(&m_tmp);

  printf("InterpMethod = %d\n", InterpMethod);

  /* Modify the MyMRIlinearTr... if I want to implement my cubic-B-spline
   * interpolation method. Otherwise, unnecessary
   */
  /* mri_out = MyMRIlinearTransformInterp(mri_in, mri_out, V_to_V, InterpMethod); */
  if (InterpMethod == SAMPLE_BSPLINE)
    mri_out = MRIlinearTransformInterpBSpline(mri_in, mri_out, V_to_V,
              SplineDegree);
  else
    mri_out = MRIlinearTransformInterp(mri_in, mri_out, V_to_V, InterpMethod);

  maxV = -10000.0;
  minV = 10000.0;
  for (z=0; z < mri_out->depth; z++)
    for (y=0; y< mri_out->height; y++)
      for (x=0; x < mri_out->width; x++)
      {
        if (MRIFvox(mri_out, x, y, z) > maxV )
          maxV = MRIFvox(mri_out, x, y,z) ;
        if (MRIFvox(mri_out, x, y, z) < minV )
          minV = MRIFvox(mri_out, x, y,z) ;
      }

  if (autoscale)
  {
    noscale = 1;

    /* compute histogram of output volume */
    HISTOGRAM *h, *hsmooth ;
    float fmin, fmax, val, peak, smooth_peak;
    int i, nbins, bin;

    fmin = minV;
    fmax = maxV;
    if (fmin < 0) fmin = 0;
    nbins = 256 ;
    h = HISTOalloc(nbins) ;
    hsmooth = HISTOcopy(h, NULL) ;
    HISTOclear(h, h) ;
    h->bin_size = (fmax-fmin)/255.0 ;

    for (i = 0 ; i < nbins ; i++)
      h->bins[i] = (i+1)*h->bin_size ;

    for (z=0; z < mri_out->depth; z++)
      for (y=0; y< mri_out->height; y++)
        for (x=0; x < mri_out->width; x++)
        {
          val = MRIFvox(mri_out, x, y, z);
          if (val <= 0) continue;

          bin = nint((val - fmin)/h->bin_size);
          if (bin >= h->nbins)
            bin = h->nbins-1;
          else if (bin < 0)
            bin = 0;

          h->counts[bin] += 1.0;
        }
    HISTOfillHoles(h) ;
    HISTOsmooth(h, hsmooth, 5)  ;
    peak =
      hsmooth->bins[HISTOfindHighestPeakInRegion(h, 1, h->nbins)] ;
    //   smooth_peak =
    //  hsmooth->bins[HISTOfindHighestPeakInRegion(hsmooth, 1, hsmooth->nbins)] ;

    smooth_peak =
      hsmooth->bins[HISTOfindLastPeak(hsmooth, 5, 0.8)] ;

    /*
      bin = nint((smooth_peak - fmin)/hsmooth->bin_size) ;

      printf("Highest peak has count = %d\n", (int)hsmooth->counts[bin]);

      bin = nint((420 - fmin)/hsmooth->bin_size) ;

      printf("bin at 420 has count = %d\n", (int)hsmooth->counts[bin]);
    */

    scale =  110.0/smooth_peak;
    printf("peak of output volume is %g, smooth-peak is %g, multiply by %g to scale it to 110\n", peak, smooth_peak, scale);
    for (z=0; z < mri_out->depth; z++)
      for (y=0; y< mri_out->height; y++)
        for (x=0; x < mri_out->width; x++)
        {
          val = MRIFvox(mri_out, x, y, z);
          MRIFvox(mri_out, x, y, z) = val*scale;
        }

  }


  printf("Output volume (before type-conversion) has max = %g, min =%g\n", maxV, minV);

  /* Finally change type to desired */
  if (mri_out->type != out_type)
  {
    printf("Change output volume to type %d\n", out_type);
    /* I need to modify the MIRchangeType function to make sure
     * it does roundoff instead of simple truncation!
     */
    /* Note if the last flag is set to 1, then it won't do scaling
       and small float numbers will become zero after convert to
       BYTE
    */
    if (out_type == 0 && noscale == 1)
    {
      //convert data to UCHAR
      mri_tmp = MRIalloc(mri_out->width, mri_out->height, mri_out->depth, out_type) ;
      MRIcopyHeader(mri_out, mri_tmp);
      for (z=0; z < mri_out->depth; z++)
        for (y=0; y< mri_out->height; y++)
          for (x=0; x < mri_out->width; x++)
          {
            value = floor(MRIgetVoxVal(mri_out, x, y, z, 0) + 0.5);
            if (value < 0 ) value = 0;
            if (value > 255) value = 255;
            MRIvox(mri_tmp,x,y,z) = (unsigned char)value;
          }
    }
    else
      mri_tmp = MRIchangeType(mri_out, out_type, thred_low, thred_high, noscale);

    MRIfree(&mri_out);
    mri_out = mri_tmp; //swap
  }

  MRIwrite(mri_out, out_vol) ;

  MRIfree(&mri_in);
  MRIfree(&mri_out);

  if (lta_src)
    MRIfree(&lta_src);
  if (lta_dst)
    MRIfree(&lta_dst);

  MatrixFree(&V_to_V);

  if (!r_to_i_out)
    MatrixFree(&r_to_i_out);

  if (!i_to_r_reg)
    MatrixFree(&i_to_r_reg);

  return(0) ;  /* for ansi */
}
Beispiel #2
0
static MRI *
MRIremoveWMOutliersAndRetainMedialSurface(MRI *mri_src,
                                          MRI *mri_src_ctrl,
                                          MRI *mri_dst_ctrl,
                                          int intensity_below)
{
  MRI  *mri_inside, *mri_bin ;
  HISTOGRAM *histo, *hsmooth ;
  int   wm_peak, x, y, z, nremoved ;
  float thresh, hi_thresh ;
  double val, lmean, max ;

  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_src_ctrl, "sc.mgz") ;
  }
  if (mri_dst_ctrl != mri_src_ctrl)
  {
    mri_dst_ctrl = MRIcopy(mri_src_ctrl, mri_dst_ctrl) ;
  }
  mri_inside = MRIerode(mri_dst_ctrl, NULL) ;
  MRIbinarize(mri_inside, mri_inside, 1, 0, 1) ;

  histo = MRIhistogramLabel(mri_src, mri_inside, 1, 256) ;
  hsmooth = HISTOcopy(histo, NULL) ;
  HISTOsmooth(histo, hsmooth, 2) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    HISTOplot(histo, "h.plt") ;
    HISTOplot(hsmooth, "hs.plt") ;
  }
  printf("using wm (%d) threshold %2.1f for removing exterior voxels\n",
         wm_peak, thresh) ;
  wm_peak = HISTOfindHighestPeakInRegion(hsmooth, 1, hsmooth->nbins-1) ;
  wm_peak = hsmooth->bins[wm_peak] ;
  thresh = wm_peak-intensity_below ;
  hi_thresh = wm_peak-.5*intensity_below ;
  printf("using wm (%d) threshold %2.1f for removing exterior voxels\n",
         wm_peak, thresh) ;

  // now remove stuff that's on the border and is pretty dark
  for (nremoved = x = 0 ; x < mri_src->width ; x++)
  {
    for (y = 0 ; y < mri_src->height ; y++)
    {
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        /* if it's a control point,
            it's not in the interior of the wm,
            and it's T1 val is too low */
        if (MRIgetVoxVal(mri_dst_ctrl, x, y, z, 0) == 0)
        {
          continue ;  // not a  control point
        }

        /* if it's way far from the wm mode
            then remove it even if it's in the interior */
        val = MRIgetVoxVal(mri_src, x, y, z, 0) ;
        if (val < thresh-5)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          nremoved++ ;
        }

        if (nint(MRIgetVoxVal(mri_inside, x, y, z, 0)) > 0)
          // don't process interior voxels further
        {
          continue ;  // in the interior
        }
        if (val < thresh)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          nremoved++ ;
        }
        else
        {
          lmean =
            MRImeanInLabelInRegion(mri_src, mri_inside, 1, x, y, z, 7);
          if (val < lmean-10)
          {
            MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
            nremoved++ ;
          }
        }
      }
    }
  }

#if 0
  for (x = 0 ; x < mri_src->width ; x++)
  {
    for (y = 0 ; y < mri_src->height ; y++)
    {
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        /* if it's a control point,
            it's not in the interior of the wm,
            and it's T1 val is too low */
        if (MRIgetVoxVal(mri_dst_ctrl, x, y, z, 0) == 0)
        {
          continue ;  // not a  control point
        }
        if (MRIcountNonzeroInNbhd(mri_dst_ctrl,3, x, y, z)<=2)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          nremoved++ ;
        }
      }
    }
  }
#endif

  /* now take out voxels that have too big an intensity diff
     with surrounding ones */
  mri_bin = MRIbinarize(mri_dst_ctrl, NULL, 1, 0, 1) ;
  for (x = 0 ; x < mri_src->width ; x++)
  {
    for (y = 0 ; y < mri_src->height ; y++)
    {
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        /* if it's a control point,
            it's not in the interior of the wm,
            and it's T1 val is too low */
        if (MRIgetVoxVal(mri_dst_ctrl, x, y, z, 0) == 0)
        {
          continue ;  // not a  control point
        }
        val = MRIgetVoxVal(mri_src, x, y, z, 0) ;
        max = MRImaxInLabelInRegion(mri_src, mri_bin, 1, x, y, z, 3);
        if (val+7 < max && val < hi_thresh)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          nremoved++ ;
        }
      }
    }
  }
  MRIfree(&mri_bin) ;

  printf( "%d control points removed\n", nremoved) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_dst_ctrl, "dc.mgz") ;
  }
  HISTOfree(&histo) ;
  HISTOfree(&hsmooth) ;
  MRIfree(&mri_inside) ;
  return(mri_dst_ctrl) ;
}
Beispiel #3
0
static int
remove_surface_outliers(MRI *mri_ctrl_src, MRI *mri_dist, MRI *mri_src,
                        MRI *mri_ctrl_dst)
{
  int       x, y, z, wsize ;
  HISTOGRAM *h, *hs ;
  double    mean, sigma, val ;
  MRI       *mri_outlier = MRIclone(mri_ctrl_src, NULL) ;

  mri_ctrl_dst = MRIcopy(mri_ctrl_src, mri_ctrl_dst) ;
  wsize = nint(WSIZE_MM/mri_src->xsize) ;
  for (x = 0 ; x < mri_src->width ; x++)
    for (y = 0 ; y < mri_src->height ; y++)
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        if ((int)MRIgetVoxVal(mri_ctrl_src, x, y,z, 0) == 0)
        {
          continue ;  // not a control point
        }
        val = MRIgetVoxVal(mri_src, x, y, z, 0) ;
#if 1
        if (val < 80 || val > 130)
        {
          MRIsetVoxVal(mri_ctrl_dst, x, y, z, 0, 0) ;  // remove it as a control point
          MRIsetVoxVal(mri_outlier, x, y, z, 0, 1) ;   // diagnostics
          continue ;
        }
#endif
#if 1
        if (val > 100 || val < 120)
        {
          continue ;  // not an outlier
        }
#endif
        h = MRIhistogramVoxel(mri_src, 0, NULL, x, y, z,
                              wsize, mri_dist, mri_src->xsize) ;
        HISTOsoapBubbleZeros(h, h, 100) ;
        hs = HISTOsmooth(h, NULL, .5);
        HISTOrobustGaussianFit(hs, .5, &mean, &sigma) ;
#define MAX_SIGMA 10   // for intensity normalized images
        if (sigma > MAX_SIGMA)
        {
          sigma = MAX_SIGMA ;
        }
        if (fabs((mean-val)/sigma) > 2)
        {
          MRIsetVoxVal(mri_ctrl_dst, x, y, z, 0, 0) ;  // remove it as a control point
          MRIsetVoxVal(mri_outlier, x, y, z, 0, 1) ;   // diagnostics
        }

        if (Gdiag & DIAG_WRITE)
        {
          HISTOplot(h, "h.plt") ;
          HISTOplot(h, "hs.plt") ;
        }
        HISTOfree(&h) ;
        HISTOfree(&hs) ;
      }
  if (Gdiag & DIAG_WRITE)
  {
    MRIwrite(mri_outlier, "o.mgz") ;
  }
  MRIfree(&mri_outlier) ;
  return(NO_ERROR) ;
}
Beispiel #4
0
static MRI *
MRIremoveWMOutliers(MRI *mri_src, MRI *mri_src_ctrl, MRI *mri_dst_ctrl,
                    int intensity_below)
{
  MRI       *mri_bin, *mri_outliers = NULL ;
  float     max, thresh, val;
  HISTOGRAM *histo, *hsmooth ;
  int       wm_peak, x, y, z, nremoved = 0, whalf = 5, total  ;

  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_src_ctrl, "sc.mgz") ;
  }

  if (mri_dst_ctrl == NULL)
  {
    mri_dst_ctrl = MRIcopy(mri_src_ctrl, NULL) ;
  }
  mri_bin = MRIbinarize(mri_src_ctrl, NULL, 1, 0, CONTROL_MARKED) ;
  histo = MRIhistogramLabel(mri_src, mri_bin, 1, 256) ;
  hsmooth = HISTOcopy(histo, NULL) ;
  HISTOsmooth(histo, hsmooth, 2) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    HISTOplot(histo, "h.plt") ;
    HISTOplot(hsmooth, "hs.plt") ;
  }
  wm_peak = HISTOfindHighestPeakInRegion(hsmooth, 1, hsmooth->nbins-1) ;
  wm_peak = hsmooth->bins[wm_peak] ;
  thresh = wm_peak-intensity_below ;

  HISTOfree(&histo) ;
  HISTOfree(&hsmooth) ;
  if (Gdiag & DIAG_WRITE)
  {
    mri_outliers = MRIclone(mri_dst_ctrl, NULL) ;
  }
  for (total = x = 0 ; x < mri_src->width ; x++)
  {
    for (y = 0 ; y < mri_src->height ; y++)
    {
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        if (nint(MRIgetVoxVal(mri_dst_ctrl, x, y, z, 0)) == 0)
        {
          continue ;
        }
        max = MRImaxInLabelInRegion(mri_src, mri_bin, 1, x, y, z, whalf);
        val = MRIgetVoxVal(mri_src, x, y, z, 0) ;
        total++ ;
        if (val+intensity_below < max && val < thresh)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          if (mri_outliers)
          {
            MRIsetVoxVal(mri_outliers, x, y, z, 0, 128) ;
          }
          nremoved++ ;
        }
      }
    }
  }

  printf( "%d control points removed (%2.1f%%)\n",
          nremoved, 100.0*(double)nremoved/(double)total) ;
  if (mri_outliers)
  {
    printf( "writing out.mgz outlier volume\n") ;
    MRIwrite(mri_outliers, "out.mgz") ;
    MRIfree(&mri_outliers) ;
  }
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_dst_ctrl, "dc.mgz") ;
  }
  MRIfree(&mri_bin) ;
  return(mri_dst_ctrl);
}
Beispiel #5
0
static MRI *
MRIremoveWMOutliersAndRetainMedialSurface(MRI *mri_src,
                                          MRI *mri_src_ctrl,
                                          MRI *mri_dst_ctrl,
                                          int intensity_below)
{
  MRI       *mri_bin, *mri_dist, *mri_dist_sup, *mri_outliers = NULL ;
  float     max, thresh, val;
  HISTOGRAM *histo, *hsmooth ;
  int       wm_peak, x, y, z, nremoved = 0, whalf = 5 ;

  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_src_ctrl, "sc.mgz") ;
  }

  mri_bin = MRIbinarize(mri_dst_ctrl, NULL, 1, 0, 1) ;
  mri_dist = MRIdistanceTransform(mri_bin, NULL, 1, -1,
                                  DTRANS_MODE_SIGNED, NULL);
  MRIscalarMul(mri_dist, mri_dist, -1) ;
  mri_dist_sup = MRInonMaxSuppress(mri_dist, NULL, 0, 1) ;
  mri_dst_ctrl = MRIbinarize(mri_dist_sup, mri_dst_ctrl, 1, 0, 1) ;
  histo = MRIhistogramLabel(mri_src, mri_src_ctrl, 1, 256) ;
  hsmooth = HISTOcopy(histo, NULL) ;
  HISTOsmooth(histo, hsmooth, 2) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    HISTOplot(histo, "h.plt") ;
    HISTOplot(hsmooth, "hs.plt") ;
  }
  wm_peak = HISTOfindHighestPeakInRegion(hsmooth, 1, hsmooth->nbins-1) ;
  wm_peak = hsmooth->bins[wm_peak] ;
  thresh = wm_peak-intensity_below ;

  HISTOfree(&histo) ;
  HISTOfree(&hsmooth) ;
  if (Gdiag & DIAG_WRITE)
  {
    mri_outliers = MRIclone(mri_dst_ctrl, NULL) ;
  }
  for (x = 0 ; x < mri_src->width ; x++)
  {
    for (y = 0 ; y < mri_src->height ; y++)
    {
      for (z = 0 ; z < mri_src->depth ; z++)
      {
        if (x == Gx && y == Gy && z == Gz)
        {
          DiagBreak() ;
        }
        if (nint(MRIgetVoxVal(mri_dst_ctrl, x, y, z, 0)) == 0)
        {
          continue ;
        }
        max = MRImaxInLabelInRegion(mri_src, mri_dst_ctrl, 1, x, y, z, whalf);
        val = MRIgetVoxVal(mri_src, x, y, z, 0) ;
        if (val+intensity_below < max && val < thresh)
        {
          MRIsetVoxVal(mri_dst_ctrl, x, y, z, 0, 0) ;
          if (mri_outliers)
          {
            MRIsetVoxVal(mri_outliers, x, y, z, 0, 128) ;
          }
          nremoved++ ;
        }
      }
    }
  }

  printf( "%d control points removed\n", nremoved) ;
  if (mri_outliers)
  {
    printf( "writing out.mgz outlier volume\n") ;
    MRIwrite(mri_outliers, "out.mgz") ;
    MRIfree(&mri_outliers) ;
  }
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
  {
    MRIwrite(mri_dst_ctrl, "dc.mgz") ;
  }
  MRIfree(&mri_bin) ;
  MRIfree(&mri_dist);
  MRIfree(&mri_dist_sup);
  return(mri_dst_ctrl);
}
static GCA_SAMPLE *
find_control_points(GCA *gca, GCA_SAMPLE *gcas_total,
                    int total_samples, int *pnorm_samples, int nregions, int label,
                    MRI *mri_in, TRANSFORM *transform, double min_prior, double ctl_point_pct)
{
  int        i, j, *ordered_indices, nsamples,
    xmin, ymin, zmin, xmax, ymax, zmax, xv,yv,zv,
    x, y, z, xi, yi, zi, region_samples,
    used_in_region, prior_wsize=5, image_wsize=3, histo_peak, n,
    nbins ;
  GCA_SAMPLE *gcas, *gcas_region, *gcas_norm ;
  double     means[MAX_GCA_INPUTS], vars[MAX_GCA_INPUTS], val, nsigma ;
  HISTOGRAM  *histo, *hsmooth ;
  GC1D       *gc ;
  float      fmin, fmax ;
  MRI        *mri_T1 = NULL ;


  if (label == Gdiag_no)
    DiagBreak() ;

  MRIvalRange(mri_in, &fmin, &fmax) ;
  nbins = (int)(fmax-fmin+1);
  histo = HISTOalloc(nbins) ; hsmooth = HISTOalloc(nbins) ;
  for (nsamples = i = 0 ; i < total_samples ; i++)
  {
    if (gcas_total[i].label != label)
      continue ;
    nsamples++ ;
  }

  *pnorm_samples = 0 ;
  printf("found %d control points for structure...\n", nsamples) ;
  if (nsamples == 0)
  {
    DiagBreak() ;
    return(NO_ERROR) ;
  }
  gcas = (GCA_SAMPLE *)calloc(nsamples, sizeof(GCA_SAMPLE)) ;
  gcas_region = (GCA_SAMPLE *)calloc(nsamples, sizeof(GCA_SAMPLE)) ;
  gcas_norm = (GCA_SAMPLE *)calloc(nsamples, sizeof(GCA_SAMPLE)) ;
  if (!gcas || !gcas_region || !gcas_norm)
    ErrorExit
      (ERROR_NOMEMORY,
       "find_control_points: could not allocate %d samples\n",nsamples);

  for (j = i = 0 ; i < total_samples ; i++)
  {
    if (gcas_total[i].label != label)
      continue ;
    memmove(&gcas[j], &gcas_total[i], sizeof(GCA_SAMPLE)) ;
    j++ ;
  }
  ordered_indices = (int *)calloc(nsamples, sizeof(int)) ;

  gcas_bounding_box(gcas, nsamples, &xmin, &ymin, &zmin, &xmax, &ymax, &zmax, label) ;
  printf("bounding box (%d, %d, %d) --> (%d, %d, %d)\n",
         xmin, ymin, zmin, xmax, ymax, zmax) ;
  for (x = 0 ; x < nregions ; x++)
  {
    for (y = 0 ; y < nregions ; y++)
    {
      for (z = 0 ; z < nregions ; z++)
      {
        /* only process samples in this region */
        nsigma = 1.0 ;
        do
        {
          for (region_samples = i = 0 ; i < nsamples ; i++)
          {
            xi = (int)(nregions*(gcas[i].x - xmin) / (xmax-xmin+1)) ;
            yi = (int)(nregions*(gcas[i].y - ymin) / (ymax-ymin+1)) ;
            zi = (int)(nregions*(gcas[i].z - zmin) / (zmax-zmin+1)) ;
            if ((xi < 0 || xi >= nregions) ||
                (yi < 0 || yi >= nregions) ||
                (zi < 0 || zi >= nregions))
              DiagBreak() ;
            xv = gcas[i].x ; yv = gcas[i].y ; zv = gcas[i].z ;
            if (xi != x || yi != y || zi != z
                || gcas[i].prior < min_prior)
              continue ;

            if (xv == Gx && yv == Gy && zv == Gz)
              DiagBreak() ;
            if (sqrt(SQR(xv-Gx)+SQR(yv-Gy)+SQR(zv-Gz)) < 2)
              DiagBreak() ;
            if (min_region_prior(gca, gcas[i].xp, gcas[i].yp, gcas[i].zp,prior_wsize, label) < min_prior)
              continue ;
            if (uniform_region(gca, mri_in, transform,
                               xv, yv, zv,
                               image_wsize, &gcas[i], nsigma) == 0)
              continue ;
            memmove(&gcas_region[region_samples],
                    &gcas[i],
                    sizeof(GCA_SAMPLE)) ;
            region_samples++ ;
            if (gcas[i].x == Gx &&
                gcas[i].y == Gy &&
                gcas[i].z == Gz)
              DiagBreak() ;
          }
          nsigma *= 1.1 ;
        } while (region_samples < 8 && nsigma < 3) ;

        if (region_samples < 8)/* can't reliably estimate statistics */
          continue ;
        if (DIAG_VERBOSE_ON)
          printf("\t%d total samples found in region (%d, %d, %d)\n",
                 region_samples,x, y,z) ;
        /* compute mean and variance of label within this region */
        for (n = 0 ; n < mri_in->nframes ; n++)
        {
          HISTOclear(histo, histo) ;
          histo->bin_size = 1 ;
          for (means[n] = vars[n] = 0.0, i = 0 ;
               i < region_samples ;
               i++)
          {
            MRIsampleVolumeFrame
              (mri_in,
               gcas_region[i].x,gcas_region[i].y,gcas_region[i].z,
               n, &val) ;
            if (FZERO(val))
            {
              if (i < (region_samples-1))
                memmove(&gcas_region[i],
                        &gcas_region[i+1],
                        (region_samples-(i+1))*sizeof(GCA_SAMPLE));
              i-- ;
              region_samples-- ;
              continue ;
            }
            histo->counts[(int)val]++ ;
            means[n] += val ;
            vars[n] += (val*val) ;
          }

          HISTOsmooth(histo, hsmooth, 2) ;
          histo_peak =
            HISTOfindHighestPeakInRegion(hsmooth, 1, hsmooth->nbins) ;
          if (histo_peak < 0)   /* couldn't find a valid peak? */
            break ;

          for (means[n] = vars[n] = 0.0, i = 0 ;
               i < region_samples ;
               i++)
          {
            if (gcas_region[i].label < 0)
              continue ;
            MRIsampleVolumeFrame
              (mri_in,
               gcas_region[i].x,
               gcas_region[i].y,
               gcas_region[i].z,
               n, &val) ;
            means[n] += val ;
            vars[n] += (val*val) ;
          }
          means[n] /= (double)region_samples ;
          vars[n] = vars[n] / (double)region_samples - means[n]*means[n] ;

          means[n] = histo_peak ;
          if (DIAG_VERBOSE_ON)
            printf("\tlabel %s[%d]: %2.1f +- %2.1f\n",
                   cma_label_to_name(label),
                   n, means[n], sqrt(vars[n])) ;
        }

        /* ignore GCA mean and variance -
           use image instead (otherwise bias field will mess us up) */
        for (i = 0 ; i < region_samples ; i++)
        {
          int r ;

          for (r = 0 ; r < gca->ninputs ; r++)
            gcas_region[i].means[r] = means[r] ;
          /*          gcas_region[i].var = var ;*/
        }

        GCAcomputeLogSampleProbability
          (gca, gcas_region, mri_in, transform, region_samples) ;
        GCArankSamples
          (gca, gcas_region, region_samples, ordered_indices) ;
        GCAremoveOutlyingSamples
          (gca, gcas_region, mri_in, transform, region_samples, 2.0) ;
        for (used_in_region = i = 0 ; i < region_samples ; i++)
        {
          j = ordered_indices[i] ;
          if (gcas_region[j].label != label)  /* it was an outlier */
            continue ;
          memmove
            (&gcas_norm[*pnorm_samples],
             &gcas_region[j],
             sizeof(GCA_SAMPLE)) ;
          (*pnorm_samples)++ ; used_in_region++ ;
        }
        if ((used_in_region <= 0) && region_samples>0)
        {
          j = ordered_indices[0] ;
          /*          gcas_region[j].label = label ;*/
          printf("forcing use of sample %d @ (%d, %d, %d)\n", j,
                 gcas_region[j].x,
                 gcas_region[j].y,
                 gcas_region[j].z) ;
          memmove(&gcas_norm[*pnorm_samples],
                  &gcas_region[j],
                  sizeof(GCA_SAMPLE)) ;
          (*pnorm_samples)++ ; used_in_region++ ;
        }
        if (DIAG_VERBOSE_ON)
          printf("\t%d samples used in region\n", used_in_region) ;
      }
    }
  }

  /* put gca means back into samples */
  for (i = 0 ; i < *pnorm_samples ; i++)
  {
    gc = GCAfindPriorGC(gca,
                        gcas_norm[i].xp,
                        gcas_norm[i].yp,
                        gcas_norm[i].zp,
                        gcas_norm[i].label) ;
    if (gc)
    {
      int r, c, v ;

      for (v = r = 0 ; r < gca->ninputs ; r++)
      {
        for (c = r ; c < gca->ninputs ; c++, v++)
        {
          gcas_norm[i].means[v] = gc->means[v] ;
          gcas_norm[i].covars[v] = gc->covars[v] ;
        }
      }
    }
  }
  HISTOfree(&histo) ; HISTOfree(&hsmooth) ;
  free(gcas_region) ;
  free(gcas) ;
  if (mri_T1)
    MRIfree(&mri_T1) ;
  return(gcas_norm) ;
}
static int
discard_unlikely_control_points(GCA *gca, GCA_SAMPLE *gcas, int nsamples,
                                MRI *mri_in, TRANSFORM *transform, char *name)
{
  int    i, xv, yv, zv, n, peak, start, end, num ;
  HISTO *h, *hsmooth ;
  float  fmin, fmax ;
  Real   val,  mean_ratio ;

  if (nsamples == 0)
    return(NO_ERROR) ;

  for (num = n = 0 ; n < mri_in->nframes ; n++)
  {
    int niter = 0 ;
    MRIvalRangeFrame(mri_in, &fmin, &fmax, n) ;
    h = HISTOalloc(nint(fmax-fmin)+1) ;
    h->bin_size = (fmax-fmin)/(float)h->nbins ;
    for (i = 0 ; i < h->nbins ; i++)
      h->bins[i] = (i+1)*h->bin_size+fmin ;

    for (i = 0 ; i < nsamples ; i++)
    {
      xv = gcas[i].x ; yv = gcas[i].y ; zv = gcas[i].z ;
      if (xv == Gx && yv == Gy && zv == Gz)
        DiagBreak() ;
      MRIsampleVolumeFrame(mri_in, gcas[i].x,gcas[i].y,gcas[i].z, n, &val) ;
      if (FZERO(val))
        DiagBreak() ;
      h->counts[nint(val-fmin)]++ ;
    }

    /* check to see  if peak is unlikely */
    hsmooth = HISTOsmooth(h, NULL, 2) ;
    do
    {
      if (gca->ninputs == 1) /*  find  brightest peak as
                                 for  n=1 it is T1  weighted  */
        peak = HISTOfindLastPeak(hsmooth, HISTO_WINDOW_SIZE,MIN_HISTO_PCT);
      else
        peak = HISTOfindHighestPeakInRegion(hsmooth, 0, h->nbins-1) ;
      end = HISTOfindEndOfPeak(hsmooth, peak, 0.01) ;
      start = HISTOfindStartOfPeak(hsmooth, peak, 0.01) ;
      for (mean_ratio = 0.0, i = 0 ; i < nsamples ; i++)
      {
        mean_ratio += hsmooth->bins[peak] / gcas[i].means[0];
      }
      mean_ratio /= (Real)nsamples ;
      HISTOclearBins
        (hsmooth, hsmooth, hsmooth->bins[start], hsmooth->bins[end])  ;
      if (niter++ > 5)
        break ;
      if (niter > 1)
        DiagBreak() ;
    } while  (mean_ratio  < 0.5 || mean_ratio > 2.0) ;

    printf("%s: limiting intensities to %2.1f --> %2.1f\n",
           name, fmin+start, fmin+end) ;
    for (i = 0 ; i < nsamples ; i++)
    {
      xv = gcas[i].x ; yv = gcas[i].y ; zv = gcas[i].z ;
      if (xv == Gx && yv == Gy && zv == Gz)
        DiagBreak() ;
      MRIsampleVolumeFrame(mri_in,gcas[i].x,gcas[i].y,gcas[i].z,n,&val) ;
      if (val-fmin < start || val-fmin > end)
      {
        num++ ; gcas[i].label = 0 ;
      }
    }
    HISTOfree(&h) ; HISTOfree(&hsmooth) ;
  }

  printf("%d of %d (%2.1f%%) samples deleted\n",
         num, nsamples, 100.0f*(float)num/(float)nsamples) ;
  return(NO_ERROR) ;
}
Beispiel #8
0
MRI *
MRIsynthesizeWeightedVolume(MRI *mri_T1, MRI *mri_PD, float w5, float TR5,
                            float w30, float TR30, float target_wm, float TE) {
  MRI        *mri_dst ;
  int        x, y, z, width, height, depth ;
  MRI        *mri30, *mri5 ;
  Real       val30, val5, val, min_val ;
#if 0
  int        mri_peak, n, min_real_bin ;
  double    mean_PD ;
  MRI_REGION box ;
  HISTOGRAM *h_mri, *h_smooth ;
  float      x0, y0, z0, min_real_val ;
#endif

  width = mri_T1->width ;
  height = mri_T1->height ;
  depth = mri_T1->depth ;
  mri_dst = MRIalloc(width, height, depth, MRI_FLOAT) ;
  MRIcopyHeader(mri_T1, mri_dst) ;
  mri30 = MRIsynthesize(mri_T1, mri_PD, NULL, NULL, TR30, RADIANS(30), TE) ;
  mri5 = MRIsynthesize(mri_T1, mri_PD, NULL, NULL, TR5, RADIANS(5), TE) ;
#if 0
  mean_PD = MRImeanFrame(mri_PD, 0) ;
  /*  MRIscalarMul(mri_PD, mri_PD, 1000.0f/mean_PD) ;*/


  h_mri = MRIhistogram(mri30, 100) ;
  h_smooth = HISTOsmooth(h_mri, NULL, 2) ;
  mri_peak = HISTOfindHighestPeakInRegion(h_smooth, 0, h_smooth->nbins) ;
  min_real_bin = HISTOfindNextValley(h_smooth, mri_peak) ;
  min_real_val = h_smooth->bins[min_real_bin] ;

  MRIfindApproximateSkullBoundingBox(mri30, min_real_val, &box) ;
  x0 = box.x+box.dx/3 ;
  y0 = box.y+box.dy/3 ;
  z0 = box.z+box.dz/2 ;
  printf("using (%.0f, %.0f, %.0f) as brain centroid...\n",x0, y0, z0) ;
  box.dx /= 4 ;
  box.x = x0 - box.dx/2;
  box.dy /= 4 ;
  box.y = y0 - box.dy/2;
  box.dz /= 4 ;
  box.z = z0 - box.dz/2;


  printf("using box (%d,%d,%d) --> (%d, %d,%d) "
         "to find MRI wm\n", box.x, box.y, box.z,
         box.x+box.dx-1,box.y+box.dy-1, box.z+box.dz-1) ;

  h_mri = MRIhistogramRegion(mri30, 0, NULL, &box) ;
  for (n = 0 ; n < h_mri->nbins-1 ; n++)
    if (h_mri->bins[n+1] > min_real_val)
      break ;
  HISTOclearBins(h_mri, h_mri, 0, n) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
    HISTOplot(h_mri, "mri.histo") ;
  mri_peak = HISTOfindLastPeak(h_mri, HISTO_WINDOW_SIZE,MIN_HISTO_PCT);
  mri_peak = h_mri->bins[mri_peak] ;
  printf("before smoothing, mri peak at %d\n", mri_peak) ;
  h_smooth = HISTOsmooth(h_mri, NULL, 2) ;
  if (Gdiag & DIAG_WRITE && DIAG_VERBOSE_ON)
    HISTOplot(h_smooth, "mri_smooth.histo") ;
  mri_peak = HISTOfindLastPeak(h_smooth, HISTO_WINDOW_SIZE,MIN_HISTO_PCT);
  mri_peak = h_mri->bins[mri_peak] ;
  printf("after smoothing, mri peak at %d\n", mri_peak) ;
  HISTOfree(&h_smooth) ;
  HISTOfree(&h_mri) ;
#endif

  min_val = 0 ;
  for (x = 0 ; x < width ; x++) {
    for (y = 0 ; y < height ; y++) {
      for (z = 0 ; z < depth ; z++) {
        if (x == Gx && y == Gy && z == Gz)
          DiagBreak() ;
        MRIsampleVolumeType(mri30, x, y, z, &val30, SAMPLE_NEAREST) ;
        MRIsampleVolumeType(mri5, x, y, z, &val5, SAMPLE_NEAREST) ;
        val = w30*val30 + w5*val5 ;
        MRIFvox(mri_dst, x, y, z) = val ;
        if (val < min_val)
          min_val = val ;
      }
    }
  }

  for (x = 0 ; x < width ; x++) {
    for (y = 0 ; y < height ; y++) {
      for (z = 0 ; z < depth ; z++) {
        if (x == Gx && y == Gy && z == Gz)
          DiagBreak() ;
        MRIFvox(mri_dst, x, y, z) += min_val ;
      }
    }
  }

  MRIfree(&mri30) ;
  MRIfree(&mri5) ;
  return(mri_dst) ;
}