a method of determining hand features information using both two dimensional image data and three dimensional image data is described . in one implementation , a method includes : receiving a 2d image frame ; receiving 3d image data corresponding to the 2d image frame ; using the 3d image data corresponding to the 2d image frame , transforming the 2d image frame ; and using the 3d image data corresponding to the 2d image frame , scaling the 2d image frame , where the transforming and scaling results in a normalized 2d image frame , where the normalized 2d image frame is a scaled and transformed version of the 2d image frame , and where the scaling and transforming is performed using a computer .