The registration method of seal based on circular template

Faced with the problem of registration of round seal, this paper proposes a method to register seal, which uses round template to do that and effectively reduces the computational. This article designs six round templates of different frequencies. At first in this paper seal image is transformed from Cartesian coordinate system to polar coordinate system, and in the polar coordinate system it uses round templates to do convolutions independently with reserved seals and ones to be verified, and then it devises a function by convolution results. Optimum registration angle can be gained by minimization of the function. Experiments show that this method is satisfied and it can be applied into practical situation.