Full-field calibration and compensation of lateral chromatic aberration based on unwrapped phase

Lateral chromatic aberration (CA) of color cameras has great effects on the imaging quality. This paper presents a novel
method to full-field calibrate lateral CA between color channels by using unwrapped phase data. Closed circle sinusoidal
fringe patterns having the optimum three-fringe numbers are generated and displayed on a liquid crystal screen
consecutively through red, green and blue channels. These closed fringe patterns are captured by a color camera. The
wrapped phase and unwrapped phase of each pixel can be calculated by using four-step phase shifting algorithm and
optimum three-fringe number method, respectively. The pixel deviations produced by lateral CA are computed by
comparing the obtained absolute phase data between red, blue, and green channels in polar coordinate system and
calibration is accomplished in Cartesian coordinate system. Lateral CA between color channels of the color camera can
be compensated by using the calibrated data. Simulated and experimental results show the validity of the proposed
calibration and compensation method.