Fingerprint direction feature obtaining method based on striped pattern

The present invention provides a fingerprint direction feature obtaining method based on a striped pattern, and relates to the fingerprint automatic identification technology, etc. The method comprises three portions consisting of fingerprint image preprocessing, obtaining of three-dimensional single-base signals and obtaining of direction information. A fingerprint image is taken as a typical striped pattern, namely two-dimensional demodulated frequency modulation and amplitude modulation signals; two radian transition operators are employed to perform analysis solution of fingerprint signals to obtain three-dimensional single-base signals corresponding to the fingerprint signals; and according to the property of the single-base signals, the fingerprint direction information is obtained under polar coordinates. Compared to a traditional method, the fingerprint direction feature obtaining method based on the striped pattern eliminates the influence of noise and gray compensation values, has high anti-noise performance, and increases the credibility of a calculation result; and moreover, the operation of obtaining the fingerprint direction information in a frequency domain can directly eliminate the amplitude information in the fingerprint signals to obtain direction information representing the fingerprint uniqueness, avoid the problem that the modulation signals are not continuous in direction caused by the cosine function value restriction and reduce the unnecessary processing links so as to reduce the time cost of the identification system and effectively improve the identification efficiency of the system.