Vector UniqueValues = new Vector();
 
for (int i = 0; i < YourCurrentArray.length; i++)
{
   if (! UniqueValues.containsElement(YourCurrentArray[i]))
   {
      // IF the current value in the array is not
      // already in the vector than the latest value
      // THEN copy this value inside the Vector
      UniqueValues.addElement(YourCurrentArray[i]);
   }
}

        Pixel[] arrayPix = new Pixel[4] ;
        arrayPix [0] = new Pixel(1,3) ;
        arrayPix [1] = new Pixel(1,1) ;
        arrayPix [2] = new Pixel(1,1) ;
        arrayPix [3] = new Pixel(1,2) ;

        final Set   set     =   new HashSet ()          ;
        set.addAll(Arrays.asList(arrayPix)) ;

        final Comparator c = new Comparator(){
            public int compare( Object o1 , Object o2 )
            {
                final Pixel pixel  = ( (Pixel ) o2 );
                final Pixel this_  = ( (Pixel ) o1 );
                final int rad1    = pixel.x + pixel.y;
                final int radThis = this_.x + this_.y;
                return radThis - rad1 ;
            }
        };
        Arrays.sort(pixels, c);

public class Pixel
{
 
    public Pixel( int i_x , int i_y )  {
        x = i_x;
        y = i_y;
    }
 
    public int x ;
    public int y ;
 
    public boolean equals( Object obj )
    {
        final Pixel pixel = ( (Pixel ) obj );
        return this.x == pixel.x && this.y == pixel.y;
    }
 
    public int hashCode()
    {
        return x +  y ;
    }
 
 
    public String toString()
    {
        return "[Pixel: x=" + x + ",y="+y+ "]";
    }
}