i don't know what that does
but it cetainly doesn't always produce such nice results
(
Bloop Fri 16 Jul, 22:10,
Tue 4 Sep 2007, 19:34,
archived)
by 'equalizing' a photograph
you can spot if there are any dust spots or blemishes on the image before saving it (that might be on the lens or sensor)
(
Boris Johnson's Press Secretary,
Tue 4 Sep 2007, 19:37,
archived)