Patent ID: 7433096

Claim:
A scanning device comprising: a light source configured to selectively illuminate an area of interest; a light sensitive receiver configured to receive light from the area of interest and generate signals based on the received light; control logic configured to power the light source at at least one power level to generate a measured signal at the light sensitive receiver corresponding to at least one known target value, and to power the light source at at least one approximate power level being a partially powered level to generate a second measured signal at the light sensitive receiver corresponding to at least one approximate target value; and calibration logic configured to determine a calibration factor for a selected pixel based on at least the known target value and the approximate target value; where the control logic is configured to power the light source at a second approximate power level different front the one approximate power level, the light source powered at the second approximate power level to generate a second approximate target value at the light sensitive receiver.