imgmaxp.c File Reference

Find the position of maximum pixel value in PET image file. More...

Go to the source code of this file.

Functions
int	imgRangeWeightedMax (IMG *img, IMG_RANGE *r, IMG_PIXEL *maxp)

Detailed Description

Find the position of maximum pixel value in PET image file.

Copyright

(c) Turku PET Centre

Author

Vesa Oikonen

Definition in file imgmaxp.c.

Function Documentation

imgRangeWeightedMax()

int imgRangeWeightedMax	(	IMG *	img,
		IMG_RANGE *	r,
		IMG_PIXEL *	maxp )

Finds voxel value weighted voxel position inside specified image range.

Returns

0 if ok, 1 invalid volume status, 2 invalid range endings, 3 inconsistent range dimensions, 4 inconsistent dimensions

Parameters

img	Pointer to IMG structure.
r	Pointer to image range inside IMG; enter NULL if whole IMG is used.
maxp	Pixel where max pixel position is written.

Definition at line 271 of file imgmaxp.c.

  {
  int zi, yi, xi, fi;
  double wsum, wz, wy, wx, wf;
 
  if(img->status<IMG_STATUS_OCCUPIED) return(1);
  if(img->dimt<1 || img->dimz<1 || img->dimy<1 || img->dimx<1) return(1);
  if(maxp==NULL) return(1);
  wsum=wz=wy=wx=wf=0.0;
 
  if(r!=NULL) {
    if(r->z1<1 || r->y1<1 || r->x1<1 || r->f1<1) return(2);
    if(r->z2<r->z1 || r->y2<r->y1 || r->x2<r->x1 || r->f2<r->f1) return(3);
    if(r->z2>img->dimz || r->y2>img->dimy || r->x2>img->dimx || r->f2>img->dimt) return(4);
 
    maxp->z=r->z1; maxp->y=r->y1; maxp->x=r->x1; maxp->f=r->f1;
    for(zi=r->z1-1; zi<r->z2; zi++) {
      for(yi=r->y1-1; yi<r->y2; yi++) {
        for(xi=r->x1-1; xi<r->x2; xi++) {
          for(fi=r->f1-1; fi<r->f2; fi++) {
            wsum+=img->m[zi][yi][xi][fi];
            wx+=(double)xi*img->m[zi][yi][xi][fi];
            wy+=(double)yi*img->m[zi][yi][xi][fi];
            wz+=(double)zi*img->m[zi][yi][xi][fi];
            wf+=(double)fi*img->m[zi][yi][xi][fi];
          }
        }
      }
    }
  } else {
    maxp->x=maxp->y=maxp->z=maxp->f=1;
    for(zi=0; zi<img->dimz; zi++) {
      for(yi=0; yi<img->dimy; yi++) {
        for(xi=0; xi<img->dimx; xi++) {
          for(fi=0; fi<img->dimt; fi++) {
            wsum+=img->m[zi][yi][xi][fi];
            wx+=(double)xi*img->m[zi][yi][xi][fi];
            wy+=(double)yi*img->m[zi][yi][xi][fi];
            wz+=(double)zi*img->m[zi][yi][xi][fi];
            wf+=(double)fi*img->m[zi][yi][xi][fi];
          }
        }
      }
    }
  }
  if(wsum<1.0E-08) return(5);
  wx/=wsum; wy/=wsum; wz/=wsum; wf/=wsum;
  maxp->x=1+(int)roundf(wx); maxp->y=1+(int)roundf(wy); 
  maxp->z=1+(int)roundf(wz); maxp->f=1+(int)roundf(wf);
  return(0);
}