#! perl -slw
use strict;
use GD;

our $A ||= 45;

my $imgIn = GD::Image->new( $ARGV[ 0 ] ) or die $!;
my $cx = int $imgIn->width / 2;
my $cy = int $imgIn->height /2;

my $imgOut = GD::Image->new( $imgIn->getBounds, 1 );
$imgOut->copyRotated( $imgIn, $cx, $cy, 0, 0, $imgIn->getBounds, $A );

(my $ofile = $ARGV[0]) =~s[(\..*?$)][.r$A$1];

open OUT, '>:raw', $ofile or die $!;
print OUT $imgOut->png;
close OUT;

system $ofile;