Optical flow estimation and the interaction between measurement errors at adjacent pixel positions

In order to estimate both components of optical flow as well as their first spatio-temporal derivatives, it is postulated that the Optical Flow Constraint Equation (OFCE) is valid in a spatio-temporal neighborhood of pixels. So far, it has been tacitly assumed that the partial derivatives of the gray value distribution - which are required for this approach at the pixel positions involved - are independent from each other. It is shown how dropping this assumption affects the estimation procedure, based on well established approaches of estimation theory. The insight gained thereby is used to develop an approach towards merging image regions based on the compatibility of optical flow estimates obtained within the regions considered for merger.