Characterization and Compensation of the Fixed Pattern Noise in the Output of a CCD Camera

A monochrome CCD camera is used in a reflectometer in order to measure the luminance of light reflected by a specimen. This application requires a compensation of the non-uniformities introduced by the optical system, also known as fixed pattern noise. We provide an image formation model and characterize the bias and the dark signal of the CCD sensor and we use a self-built integrating sphere with an inner diameter of 500mm as a uniform light source in order to characterize the photo sensitivity of the whole optical system. Finally, a new effective approach to compensate the fixed pattern noise pixel by pixel and in dependence of the exposure time is proposed.