The document is a dissertation submitted by Deepika Joshi towards the partial fulfillment of requirements for the degree of Master of Technology in Computer Engineering from Poornima University in Jaipur, India. It discusses the development of an efficient technique for brain tumor extraction from MRI images using entropy measures. The technique aims to effectively detect and diagnose tumors in early stages. Various entropy measures such as Shannon, Renyi, Havrda-Charvat, Kapur and Vajda entropy are used to select thresholds and segment tumors from MRI images. Simulation results for different entropy measures are presented and analyzed.