You don't give any indication of the size of the image you're scaling from.
If you're scaling a small image up to a large image you're going to lose information, Imager can't make the image detail up for you.
You might want to try setting scale()'s qtype parameter to 'mixing' which uses a different algorithm to scale the image, eg:
my $scaled_order_image = $order_image->scale( xpixels => 720, qtype => 'mixing' );
If you want to try sharpening the image you could use either the convolution of unsharp mask filter:
# filters work in-place and don't return a new image
# either of the following will sharpen the image
$scaled_order_image->filter(type=>'conv', coef => [ -0.5, 2, -0.5 ]);
$scaled_order_image->filter(type => 'unsharpmask');
The filters are documented in perldoc Imager::Filter.
I also have a page with example of many of the filters.
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