Hello,
Allow me to introduce my setup first:
Joomla! 3.4.8
PHP 5.4.45
VirtueMart 3.0.6.2
Template version 1.0.0
Framework version 3.0.2

On this example you may see that the original image which is actually a rectangle:

is actually cropped as square: kover21.ru/rossijskie-kovri/akvarel-de-lyuks/i912n-70-detail
Thumbnails are cropped in the same way.

For this kind of product that isn't appropriate, so i would like to know if it is possible to change that values somewhere in the settings, or in the code.

Thanks a lot.

Dear sir,
Could you please feel free to post your question into our ticket system? We need more detail your information to check.

Thanks.