  It is at times important to detect human presence automatically in secure
environments. This needs a shape recognition algorithm that is robust, fast and
has low error rates. The algorithm needs to process camera images quickly to
detect any human in the range of vision, and generate alerts, especially if the
object under scrutiny is moving in certain directions. We present here a
simple, efficient and fast algorithm using skeletons of the images, and simple
features like posture and length of the object.
