Hi, there used to be a nice picture framing shop in the city, in Korona plaza 1st floor, but I haven't been there for a while. According to the internet it still exists. It is on Várkerület, so you can reach it easily, but I'm not sure if they do framings within the day.
here is the phone number and opening hours at the bottom of the page:
here is a better map:
Thank you so much! Will check it out.