I have a video of Brownian motion of microbes under a microscope. From this video, I need to calculate the angular velocity of a particular prominent cell. From my understanding, what I know is that I need to identify some points within the cell, track its location at successive time frames and thus get the velocity by dividing the distance traveled by that point by time.

Now my question is given the quality of video I have what is the best way to track some points within the video? My quality of video is such that manual identification of points at different time snapshots within the video is not possible.

Attached a particular time snapshot of the video as an image here.A particular time frame of the microbe video

I have applied edge detection using Sobel method on different time frames and then applied Hough Transform to detect lines within the images. But that didn’t result in any fruitful visualization of rotation. Attached images of some results which I got. [Result after edge detection and Hough Transform] (https://i.sstatic.net/M6Km80op.jpg)