Osteoporosis is one of the most common bone diseases over the world, this disease causes a high risk of fracture, an early diagnosis of the osteoporosis can help avoiding the risk of fracture. Several methods have been proposed to detect the presence of this disease. In this paper we propose a method of osteoporosis diagnosis based on bone X-Ray images, using the frequency separation and fractional Brownian motion. The classification is performed using the Support Vector Machines classifier. The proposed method shows its good classification performance achieving an accuracy rate around 94 %.