/*This is an extract from the main program (lens_distortion_estimation.c), dealing with the 
* points coordinate normalization
*/ 

/* POINT NORMALIZATION */
  // (x,y):     normalized coordinates, hence, image center = (0,0)
  // (xx,yy):   opriginal pixel coordinates, hence, image center = (x0,y0)

  factor_n=0.0; cont=0;
  for(int m=0;m<Nl;m++){
     for(i=0;i<Np[m];i++){
      xx[m][i]=x[m][i];
      yy[m][i]=y[m][i];
      x[m][i]-=x0;
      y[m][i]-=y0;
      cont++;
      factor_n+=x[m][i]*x[m][i]+y[m][i]*y[m][i];
    }
  }
  factor_n=sqrt(factor_n/cont);
  for(int m=0;m<Nl;m++) for(i=0;i<Np[m];i++){ x[m][i]/=factor_n; y[m][i]/=factor_n; }