Resize screenshot with lua

it's possible?
Thanks.

Could it be, that version 4.2 resizes the screenshot automatically to the rendered size? My game is 1920 x 1080 but I test and play it with 1280 x 720. With 4.1 the screenshots are 1920 x 1080 pixels, now with 4.2 the screenshots are 1280 x 720 pixels... it's OK but I wondered...

I hadn't noticed it was now taking screenshots at surface area size. That's actually better than it exporting them at default resolution though, no? At least it's true to what's on the screen. I'm sure the save game thumbnails will still be taken as usual though?

By the way: can I save the screenshot as jpg?

No. It has to be png. That's what it says in the documentation for it. I tried saving as jpg but it didn't work.