The uuencode module of Tcllib includes uudecode functionality.
For example, given a news post image.news, we can do:
package require uuencode set data [uuencode::uudecode -file image.news] foreach img $data { set f [open [file tail [lindex $img 0]] w] fconfigure $f -translation binary puts -nonewline $f [lindex $img 2] close $f }
See also uuencode