What motion estimation techniques that could estimate the motion of every pixel?

Question

I'm trying to estimate a motion from a video, however based on my finding, those methods usually meant for large motion and sparse in nature.

Optical flow: Sparse and fail to detect sub-pixel motion

Phase-based: Only applicable to global shutter camera for accurate displacement

Welcome any suggestion/discussion you guys have in mind that would allow me to determine sub-pixel motion for every pixel that applicable to rolling shutter camera! Thanks in advance!

Answer 1

You can use Farneback to estimate dense flow. In OpenCV, the function call is calcOpticalFlowFarneback().

Please note that the initial flow is important and you can use one of OPTFLOW_FARNEBACK_GAUSSIAN or OPTFLOW_USE_INITIAL_FLOW.

It depends on the depth of the pre calculation to estimate the segmentation before calculating the frame to frame flow.