You need to drop the qw() and change $parameters to an array e.g 
my @parameters = (colorspace = >'gray', compression = >'none');

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Because as it stood $parameters was being assigned compression=>'none' as your code really looked like this 
my $parameters = (q[colorspace=>'gray'], q[compression=>'none']);

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See. perlop for more info on the workings of qw().
HTH

_________
broquaint

In reply to Re: dynamic methods with variables by broquaint
in thread dynamic methods with variables by jorg

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