Complex sinusoidally modulated imaging for real-time pixel-wise optical flow detection

In this paper, we study optical flow determination with Complex Sinusoidally Modulated Imaging (CSMI) using a novel imaging device, the correlation image sensor (CIS). The proposed method is based on a newly obtained relation what we call the optical flow identity (OFI) between intensity image and complex sinusoidally-modulated image captured simultaneously by the CIS. This equation is complex-valued and the optical flow is a 2-dimensional vector for each pixel. Therefore, it is possible to compute the optical flow from one pixel value and its spatial gradient. Since the OFI does not involve time derivative, information on a single frame is sufficient. Moreover, the velocity limitation due to the spatio-temporal aliasing and approximate frame differentials used in conventionalt methods is avoided.