Patent ID: 8547336

Claim:
A method comprising: generating for a first group of photosensitive elements a first quasi-sinusoidal signal at a first time, and a second quasi-sinusoidal signal at a second time in response to motion of light received thereon in a first direction; computing from the first and second quasi-sinusoidal signals a phase angle change; computing from the first and second quasi-sinusoidal signals a radius value; generating for a second group of photosensitive elements a third quasi-sinusoidal signal at the first time, and at the second time a fourth quasi-sinusoidal signal in response to the motion of the light received thereon in the first direction; computing from the third and fourth quasi-sinusoidal signals another phase angle change; computing from the third and fourth quasi-sinusoidal signals another radius value; and combining phase angle changes using radius-weighted-averaging to provide a single weighted average phase angle change resulting from the motion of the light in the first direction.