my $text = 'Blah Blubb Moep Malp Foo Bar Baz!';
my $image = Image::Magick->new;
$image->Set( size => '800x600' );
$image->ReadImage('xc:none');
my (@params)= $image->QueryFontMetrics(font=>'arial.ttf', pointsize=>30, text=>$text);

use Data::Dumper;
print Dumper \@params;