Motion tracking apparatus and system

1. A motion tracking system for tracking a user, the system comprising:

a motion detecting unit operable to generate motion information for a user from input signals;

a camera operable to capture images of the user;

a body tracking unit operable to generate tracking information for the user by using the images of the user captured by the camera; and

a data merging unit operable to merge the generated tracking information and the generated motion information, wherein the motion information is used to modify at least a portion of the tracking information,

wherein the input signals are received at a different rate to that at which the camera is operable to capture images of the user.

2. The motion tracking system according to claim 1 , comprising an image rendering unit operable to generate images for display in dependence upon the merged information.

3. The motion tracking system according to claim 2 , wherein the image rendering unit is configured to generate the images by rendering of an avatar that moves in a virtual environment in a manner that depends upon the user's motion in the real world.

4. The motion tracking system according to claim 1 , wherein the input signals are received from one or more peripheral devices associated with a part of the user's body, and indicate motion of the user's body.

5. The motion tracking system according to claim 1 , wherein the input signals are received at a same rate as a frame rate of content displayed on a display associated with the motion tracking system.

6. The motion tracking system according to claim 1 , wherein the body tracking unit is operable to use the images of the user captured by the camera to update a skeletal model.

7. The motion tracking system according to claim 6 , wherein the skeletal model comprises the height and dimensions of a user.

8. The motion tracking system according to claim 6 , wherein the skeletal model comprises information about a range of motion of the user's joints.

9. The motion tracking system according to claim 1 , wherein the motion information relates only to the user's head and/or hands.

10. The motion tracking system according to claim 1 , wherein the input signals are received at times offset from times at which images are captured by the camera.

11. The motion tracking system according to claim 1 , further comprising a head-mountable display.

12. A motion tracking method for tracking a user, the method comprising:

generating, using a processing device, tracking information for a user using images of a user obtained with a camera;

generating, using the processing device, motion information for the user from input signals; and

merging, using the processing device, the generated tracking information and the generated motion information, wherein the motion information is used to modify the tracking information,

wherein the input signals are received at a different rate to that at which the camera is operable to capture images of the user.

13. The motion tracking method according to claim 12 , comprising generating images for display in dependence upon the merged information.

14. A non-transitory computer-readable recording medium having computer readable instructions stored thereon, the instructions, when executed by a computer, cause the computer to perform a motion tracking method, the method comprising:

generating tracking information for a user using images of a user obtained with a camera;

generating motion information for the user from input signals; and

merging the generated tracking information and the generated motion information, wherein the motion information is used to modify the tracking information,

wherein the input signals are received at a different rate to that at which the camera is operable to capture images of the user.

15. The recording medium of claim 14 , wherein the method further comprises generating images for display in dependence upon the merged information.