Geometric distortion correction for sinusoidally scanned atomic force microscopic images

A method for correcting the geometric distortion of the images scanned sinusoidally by an atomic force microscope (AFM) was proposed. The generation mechanism of the geometric distortion in sinusoidally scanned AFM images was analyzed. Based on the relationship between the coordinates of uniformly scanned points and those of sinusoidally scanned points, a transformation formula was obtained for correcting the geometric distortion when the sampling frequency is a constant. By comparing the forward method with the backward method, a hybrid method for correcting the geometric distortion of the sinusoidally scanned images was proposed. This method takes advantages of both the forward method and the backward method, and was proven to be better than either of them. In addition, it is a universal approach to correct the geometric distortion of the images scanned in the sinusoidal mode.