in reply to Accessing/Printing Complex Data Structure

Given this bit of your code (note: indenting helps):
foreach my $img ( sort keys %images ) { foreach ( @{$images{$img}} ) { # this is line 11 ...
and this bit of output from Data::Dumper:
'intra-d_1050044970' => { 'frags' => [ ....
The problem is that your second "foreach" is treating the content of "$images{$img}" as a reference to an array, when it is actually a reference to a hash (and the first key of that hash, as shown by Dumper, is 'frags'). The code should have been:
foreach my $img ( keys %images ) { foreach my $typ ( keys %{$images{$img}} ) { ... # next layer -- content of $images{$img}{$typ} -- depends o +n value of $typ: ... # 'frac' has AoAoH ... # others have just a hash
Hope that helps.