how big should the picture be for printing it in a 80cm(Long) x 50cm (High) paper ?

[aggelos123]

so i want to print a poster ...how big should the digital picture be so when its printed in the poster (which is 80cm long and 50 cm high) to be clear?would 1920x1080 be printed clearly?

 

[kanewolf]

12MP or higher should be good. Obviously, any flaws in the original image will be more visible.