Lens vignetting correction algorithm in digital cameras

摘要

A lens vignetting correction method for use in imaging systems such as digital cameras employs a polynomial correction function F=ar²+br⁴+c, wherein r is a distance to a center of correction. A calibration image is obtained using the imaging system, then the correction function applied to the calibration image is least-squares fit to determine the variable coefficients a, b and c. Subsequent raw images from this imaging system are corrected by applying the correction function thereto on a pixel-by-pixel basis. A recursive technique is used to obtain correction function values for given pixel locations from modification of values for preceding pixel locations.