The spatio-temporal constraint equation for computation of the optical flow holds only over local spatio-temporal regions where motion is translational with constant velocity or over non-moving background regions where the image velocity is zero. Where the expression is true, it is possible to estimate the image motion vector of local image regions by minimizing the squared error over the local region. The expression is not true in the moving boundaries of moving objects over a stationary background, over regions with multiple moving objects, or over objects not in purely translational motion. Under these conditions, the accurate computation of motion vectors is not possible using this method. However, the error squared term, itself, may be used as a moving target indicator able to segment moving targets from noise and background clutter. This paper proposes and assesses the