Analyzing orthographic projection of multiple 3D velocity vector fields in optical flow

Abstract

This paper describes a method for analyzing multiple optical flow fields in optical flow and reconstructing 3D velocity vector fields. First, the discussion is concentrated on purely rotational motion. This method estimates a set of descriptive parameters of a purely rotational optical flow field such as projected rotational axis and projected angular velocity of a purely rotational optical flow field and extracts rotational optical flow fields specified by the parameters from input optical flow. This process based on the Hough transform utilizes constraints holding between parallel optical flow vectors to construct the parameter space. Taking correspondence between two rotational optical flow fields in two different views is profitable to decompose the descriptive parameters and reconstruct the 3D rotational velocity vector fields. The method proposed is applied to computer generated optical flow fields. Second, a discussion suggests that the method is applicable to analyzing general motion, from the fact that its optical flow field is essentially the same as that of purely rotational motion, though the test for the general motion is not presented here.