use strict;
use XML::Rules;
my $parser = XML::Rules->new(
  style => 'filter',
  rules => {
    _default => 'raw',
    image => sub {
      my ($tag, $attr) = @_;
      delete $attr->{scope} if $attr->{scope} eq 'local';
      return $tag => $attr;
    }
  }
);

$parser->filterfile( $input_file, $output_file);