at this time, there is no such option.

but you could vote for that, maybe they will implement this in next version:
https://stackideas.com/voices/easydiscuss/item/1407

Hello Kane,

I'm really sorry that delayed of this reply,
Unfortunately we do not have this option from backend to configure this, but i will add this suggestion in our feature request list and see if we can implement in the future.

Thanks n00bster heading up on this.

Hi, can anyone tell me please, did this ever get resolved, users are posting 6K x 4K images and they are too big!

hey Mark,

Are you referring when the user post image using bbcode img tag or upload image?

If upload attachment image file, we did have a setting from backend to control maximum image file user can upload.

If post image using bbcode img tag, that is not possible to control it. ;(