Absolute tracking in a sub-pixel range

摘要

An optical navigation device for absolute tracking in a sub-pixel range. The optical navigation device includes an image sensor and a tracking engine. The image sensor includes a pixel array to generate a plurality of tracking images. The tracking images correspond to incident light at the pixel array. The tracking engine determines a sub-pixel displacement value of a tracking surface based on a comparison of at least two of the tracking images. The tracking engine includes a sub-pixel approximation engine and a linear approximation engine. The sub-pixel approximation engine generates an intermediate sub-pixel displacement value based on a sub-pixel approximation according to a non-linear sub-pixel distribution. The linear approximation engine generates a final sub-pixel displacement value from the intermediate sub-pixel displacement value.