A camera module forms digital images and measures an ambient light level.
A device such as a digital camera, a telephone, or a PDA containing the
camera module can set lighting levels of I/O systems such as keypads or
displays according to the ambient light level to thereby save power or
optimize functionality of the I/O systems. A dedicated sensor in the
camera module or one or more selected sensors in the imaging array of the
camera module can measure the ambient light level.