Application of Fourier-Mellin transformation (FMT) in distortion-invariant image recognition

Fourier-Mellin transformation (FMT) was added in the optical joint transform correlator (JTC) recognition of the rotating and rescaling targets to overcome the low recognition ratio. The log?polar transformation, Mellin transformation and Fourier transformation used respectively in the FourierMellin Transformation (FMT), which has the invariance of rotation, scale and translation (RST), can eliminate the effect of distortion and improve the performance of image recognition. The simulation experiment of the correlation recognition for the targets with rotation angle of 0-40 and the dimension variation range of 0-20% was carried out with JTC. In comparison with the results of FMT, it is found that FMT added to JTC can realize the distortion-invariant image recognition.