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Rotation-invariant scene matching with multi-sample parallel estimation in volume holographic correlator

The volume holographic correlator can be used in the fast scene matching. However, the traditional volume holographic recognition method is unable to implement rotation-invariant scene matching. In the multi-sample parallel estimation method, the intensity of the multiple correlation spots can also reflect the information of the rotation angle between the target image and the template image. Thus it can be used to derive the rotation angle in the post processing and the rotation-invariant scene matching can be realized. The function between the rotation angle and the intensity value of the correlation spots is presented. The experimental results show the validity of the proposed method. The rotation angle of the target image can be precisely derived and the maximum rotation angle is as big as five degree. This method is able to save much capacity of the volume holographic correlator, enlarge the scene matching scope and improve the recognition accuracy.