Determine if bulk movement is to the left or right of movie frame?

I have a bunch of multipage TIFFs of red blood cells (RBC's) moving within a microfluidic chip (each TIFF stack is 4000 frames long). In some of these videos the cells are moving left-to-right, and in other videos cells move right-to-left. There is hardly ever any movement in y and there are never cells travelling left-to-right and right-to-left in the same video. In a normal video about 200 cells cross the region of interest in about 40 frames each.

Is there any quick way to, given a video, determine if the cells are moving to the left or to the right? no information needed about velocity

Answer 1

[Jyothis Gireesh]

It is my understanding that you want to calculate the direction of motion of cells in a video.

For this purpose, you may make use of optical flow techniques in Computer Vision. Optical flow techniques are usually used to estimate the apparent motion of objects, surfaces and edges in a visual scene. You may make use of the following link to get a high-level overview about the technique.

https://www.mathworks.com/discovery/optical-flow.html

Regarding the implementation, you may use the estimateFlow function available in the Computer Vision toolbox. This function takes the video file and any one frame as input and returns an opticalFlow object. This contains information about the velocity, phase and amplitude components of the optical flow.

For detailed information on using estimateFlow function you may refer to the following link.

https://www.mathworks.com/help/vision/ref/opticalflowhs.estimateflow.html

Hope this helps!