Save print screen as jpg

reference

irfanview has many commands, example
(note: screenshot1 and screenshots are path-variables)
~printscreen::
ifexist,%screenshot1%\irfanview.exe
    {
    run, "%screenshot1%\irfanview.exe" "/capture=0 /convert=%screenshots%\%A_now%_screenshot.jpg"
   sleep,500
   run,%screenshots%  ;open folder
   return
    }
return


~!printscreen::       ;copy only active window
ifexist,%screenshot1%\irfanview.exe
    {
    run, "%screenshot1%\irfanview.exe" "/capture=2 /convert=%screenshots%\%A_now%_screenshot.jpg"
   sleep,500
   run,%screenshots%
   return
    }
return