Abstract: A method for determining the key of an audio signal such as a music track. Portions (106) of the audio signal are analysed (104) to identify (108) a musical note and its associated strength (110) within each portion. Some notes identified in a portion may be ignored (118) to enable notes related to the key to be more readily distinguished. A first note is then determined (124) from the identified musical notes as a function of their respective strengths. From the identified musical notes, at least two further notes are selected (128) as a function of the first note. The key of the audio signal is then determined (130) based on a comparison of the respective strengths of the selected notes.

Abstract: Objects of a three dimensional (3D) virtual world that are represented on a two dimensional (2D) image plane are provided with labels which are generated in the 2D image plane itself. The labels are in spatial registration with the object as represented on the 2D image plane. The generation of the labels in the 2D image plane avoids problems relating to perspective and aliasing which can occur when labels are provided in the virtual world itself and are rendered from the 3D virtual world.

Abstract: Objects of a three dimensional (3D) virtual world that are represented on a two dimensional (2D) image plane are provided with labels which are generated in the 2D image plane itself. The labels are in spatial registration with the object as represented on the 2D image plane. The generation of the labels in the 2D image plane avoids problems relating to perspective and aliasing which can occur when labels are provided in the virtual world itself and are rendered from the 3D virtual world.