An optical pointing device includes a light source configured to respond
to a drive current to provide at least partially coherent light to
illuminate an imaging surface to thereby generate reflected images. A
navigation sensor is configured to generate digital images based on the
reflected images, and generate movement data based on the digital images
that are indicative of relative motion between the imaging surface and
the optical pointing device. A light source driver is configured to
provide the drive current to the light source. A drive current controller
is configured to calibrate the drive current based on selected digital
images.