question: public static double [ ] [ ] computeWeightMatrix ( int bpp ) { final int dim = bpp * bpp * bpp ; final double [ ] [ ] m = new double [ dim ] [ dim ] ; final double max = 3. * ( bpp - 1. ) ; for ( int x = 0 ; x < dim ; x ++ ) { final int rx = ( x / bpp ) / bpp ; final int gx = ( x / bpp ) % bpp ; final int bx = x % bpp ; for ( int y = x ; y < dim ; y ++ ) { final int ry = ( y / bpp ) / bpp ; final int gy = ( y / bpp ) % bpp ; final int by = y % bpp ; final double dr = Math . abs ( rx - ry ) ; final double dg = Math . abs ( gx - gy ) ; final double db = Math . abs ( bx - by ) ; final double val = 1 - ( dr + dg + db ) / max ; m [ x ] [ y ] = m [ y ] [ x ] = val ; } } return m ; }
target:  Compute weight matrix for a RGB color histogram