How to change image compression strength in OpenCart 2.x?

Question

opencart

Hello, at one time I found information on the Internet how to lower the quality of thumbnails in the list of categories, now I need to return it back, but ironically I forgot in which document the rules, I only remember that it seems like in the system directory
Here is an example of how it used to be and as after lowering the quality during compression...
Moreover, the quality of images is reduced only in the list of categories, but if you open the product card, then the quality there is high...

Definitely, this is not the system/library/image.php file, but some other one..
Please help me remember

Answer 1

Maybe you just changed from the admin panel and forgot?