c:\test>p1
[0] Perl> sub rgb2n { unpack 'N', pack 'CCCC', 0, @_ }
;;
[0] Perl> print rgb2n( 2**24 / $_ ) for reverse 1 .. 10;;
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
10027008
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
13041664
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
0
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
4784128
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
11141120
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
3342336
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
0
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
5570560
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
0
Character in 'C' format wrapped in pack at (eval 6) line 1, <STDIN> line 3.
0