Nonlinear aberration correction of lens in image mosaic

A correction method with high precision for Digital Camera (DC) lenses is proposed to meet the needs of the seamless mosaic of large scale images. The shortcomings of present algorithms are analyzed and a kind of detecting algorithm is proposed. In consideration of the structural characteristics of a chessboard pattern that the pixels in the images are central symmetrical for the points of intersection and antisymmetric for the lines of intersection of every two adjoining square panes, the precise coordinates of feature points can be decided by calculating the symmetry index and antisymmetry index for every pixel. Then, combined with the polynomial transform and bilinear interpolation techniques, a high-precision correction method for nonlinear aberration of DC images is put forward. The experiment shows the mean of horizontal error is 0.43 pixel and the mean of vertical error is 0.36 pixel after correction. These results show that proposed method has advantages in simple calculation, robust to noise, projective and distortion aberration and convenient for automatic detection. The correction and mosaic for a map photo is carried out, results prove further the effectiveness of the method by its application in the real map photo mosaic.