摘要
针对电容式传感器采集的指纹图像的特点,本文提出了一套完整的指纹图像预处理组合算法。该算法充分考虑到了采集到的指纹图像的质量和图像面积等问题,且从全局角度出发在当前原有算法基础上加入了两次滤波去噪来增强指纹纹线并有效消除噪声以得到更清晰准确的处理结果。算法首先对采集到的指纹图像采用边缘保持滤波法去除噪声;然后使用基于纹路方向性的Cabor滤波图像增强算法增强去噪后的指纹图像,减少因指纹旋转及平移因素造成的误差;接着对增强后的图像采用动态阈值法进行二值化处理并进一步地二次滤波去噪;最后采用基于形态学的细化算法对二值图像进行细化将其变为点线图。实验证明,通过该算法处理后的图像很好地保留了纹线的关键信息,有利于后续的指纹特征提取和匹配。
A complete combinatorial pre-processing algorithm based on the characteristic of capacitance sensor fingerprint image was pointed out. The problems were considered in this algorithm such as fingerprint image＇s quality and area and so on, and the filter was increased twice based on the original algorithm to enhance fingerprint ridge and eliminate noises effectively for better preprocessing result. Firstly, the fingerprint image was filtered by edge keep filter. Then, the image was enhanced by the algorithm based on the lines of directional of Gabor filter, which could reduce the effect of the rotation and shift of the images on the fingerprint recognition. Finally, the thinning image was received in the morphological thinning method after dynamic threshold method and the second filter were used to receive a binary image. The experimental result proves that this algorithm is effective to fingerprint image and helpful to the fingerprint feature extraction and matching.
出处
《光电工程》
CAS
CSCD
北大核心
2009年第4期140-145,共6页
Opto-Electronic Engineering
基金
北方工业大学科研基金资助项目
关键词
指纹预处理
滤波
方向图
Cabor滤波增强
二值化
细化
fingerprint image pre-processing
filter
direction image
Gabor filter enhancement
binarization
thinning
