How can I change the size of product image?

[Tasifama]

How can I change the size of this square?

I Would like to Reduce to 170x200. 

 

 

 

 

 

Edited April 25, 2016 by clintonsnow (see edit history)

[NemoPS]

In the back office preference, images, it should be large_default

[OpenSource Expert]

This dimension is not provided as default. To add a new image type, go to Preferences menu>Images sub-menu in the back office and on the page that opens click on the Add new image type button (in PrestaShop 1.5 it's labeled just Add new). You will get a form, simply give the name of the image type, 

fill height and width in pixels and save your setting.

[NemoPS]

He doesn't need to "add" a new one, that's the large one, he would have to edit the template if he added another type