Real-time on field scale estimation of a target with accuracy is a research problem in visual tracking. Itis important due to its applications in domains like surveillance, robotics and automation. In general,only the initial position of the object is known, and the trajectory of the object motion is desired tobe traced. It becomes further difficult due to problems like fast motion of the objects, motion blur,size and scale variations. Existing algorithms estimate the size of target based on exhaustive scalesearch which faces problems when scale varies a lot and involves expensive computation. They learnsize or appearance model of target by using generative or discriminative approach.