[1] The application of scan conversion is wide and covers video projectors, cinema equipment, TV and video capture cards, standard and HDTV televisions, LCD monitors, radar displays and many different aspects of picture processing.
There are two distinct methods for changing a picture's data rate: This conversion is done using large numbers of delay cells and is appropriate for analog video.
In this method, a picture is stored in a line or frame buffer with n1 speed (data rate) and is read with n2 speed, several picture processing techniques are applicable when the picture is stored in buffer memory including kinds of interpolation from simple to smart high order comparisons, motion detection and … to improve the picture quality and prevent the conversion artifacts.
[1] The process in practice is applicable only using integrated circuits in LSI and VLSI scales.
Timing, interference between digital and analog signals, clocks, noise and exact synchronization have important roles in the circuit.