摘要： 设计一组方向滤波器，该滤波器包含8个方向的滤波器模板。将水平方向滤波模板中可能发生旋转溢出的位置赋零值，其位置参数值按照由中心向外围参数逐渐衰减的规律由一段基于黄金分割率的斐波那契数列段确定，其余7个方向的滤波模板由水平方向滤波模板旋转得到。在保证各个方向滤波器模板结构一致性的同时，既解决模板旋转溢出的问题，又使参数在对应方向上分布更具规律性。实验结果表明，该组方向滤波器模板对低质量指纹图像具有明显的增强效果，能更好地连接断裂脊线并分离粘连脊线。

关键词: 指纹增强, 方向滤波, 黄金分割率, 滤波模板

Abstract: A Directional Filter Bank(DFB) containing eight directional filter masks is proposed. The filter coefficients which probably go beyond the range of the horizontally oriented mask are assigned zero value, a section of Fibonacci sequence based on the golden segmentation ratio is chosen as the other mask coefficients according to the rule of gradually decrease by the center to peripheral. The other seven masks are rotated from the horizontally oriented mask. The especial structure can ensure the consistency of all the filter masks’ structure. This DFB not only solves the overflow problem of filter masks, but also ensures the coefficients on the rotated masks distribute more regularly. The performance of this DFB is evaluated with some typical low quality images of FVC database. Experimental results show that the proposed DFB has dramatic effect to low quality fingerprint images, it can connect the broken fingerprint and enhance the ridges more efficiently.

Key words: fingerprint enhancement, directional filter, golden segmentation ratio, filter mask

中图分类号: 

• TP391.41