this.findSmallest = function(exclude)
      {
        var minRadius = 1000.0, minIndex; 
        var i; 
        
        for(i = 0; i < this.blobs.length; i++)
        {
          if(i == exclude || this.blobs[i] == null)
          {
            continue; 
          }
          if(this.blobs[i].getRadius() < minRadius)
          {
            minIndex = i; 
            minRadius = this.blobs[i].getRadius();  
          }
        }
        return minIndex; 
      }