How to classify direction of step using image processing

A person holds smartphone (while he walks) in front of him and record video in live. That means the person is moving with the camera

The thing is - i need to determine which direction he turned - left/right/backward/forward (these only)

Whats is the simplest way to do that? If there isn't, what should i change so it will be?

Answer 1

[Tarunbir Gambhir]

If you have access to the Computer Vision Toolbox, you may refer to 'estimateFlow' function to get the optical flow matrix. Using the average of vector directions in the optical flow matrix, you can estimate the direction of camera movement.

You could also have a look at 'vision.BlockMatcher' function, as it can also give horizontal and vertical components of motion between two inputs.