There has been a lot of work put it developing software that can interpolate frames for video editing and compositing applications. Twixtor in the late 90’s was perhaps the first time the technology could make something worthwhile and really produce acceptable results in a computationally acceptable timeframe.
Today the most used algorithm is Adobe’s Optical Flow in Premiere or Time Warp in After Effects which use vector directional plus acceleration of pixel values to derive in between frame data to generate new frame information from the preceding frame as point A and the next frame as point B. The results can do some wonders to really slow down things above the frame rate ceiling of the camera.
