1. A method for object tracking comprising: detecting changes in a plurality of consecutive frames received from an image sensor containing one or more objects; projecting the detected changes onto a dimension to produce a spatio-temporal three-dimensional (3D) volume; converting the 3D volume to form a two-dimensional (2D) spatio-temporal image; and extracting one or more bands from the 2D image to track movement of the one or more objects in one dimension.