Accuracy itself a complete statement to describe a final destination. Now days, we have so many image processing tools available. By using that, it is very easy to extract the information or details of background of an Image taken from thermal imaging camera. Without any special function or a tool it is a very cumbersome task to be carried out for any researcher. Normally, thresholding technique is applied to separate out different objects from the background present in an image. To get an accurate result and enhancement in analysis and measurement of any object of thermal image, it is required to apply essential steps in an algorithm used in addition with thresholding. In this paper, thermal image of an electrical system is used. To protect the circuit, it is necessary to distinguish area of an acquired thermal image by high heated area and normally heated area. Now to protect circuit, it is necessary to measure high heated area accurately where normally heated area is ignored. In this paper I have used LoG (Laplacian of Gaussian), an optimal edge detection technique in addition with thresholding, and achieved high accuracy in a result identified. The result or measured area is in terms of pixel for simplicity.