The algorithm firstly decomposes a fingerprint image into approximation and detail by wavelet transform.Then the detail signal is submitted to DFB for directional filter-based analysis.

• 应用小波变换分离出低频信号和高频信号，对高频信号送入方向性滤波器组进行方向性子带分解，对各方向子带图像分块，根据块能量分布情况对子带图像重新加权处理。