基于快速对称小波变换的高效模糊指纹图象压缩方法

自动指纹识别系统ＡＦＩＳ（ａｕｔｏｍａｔｅｄｆｉｎｇｅｒｐｒｅｎｔｉｄｅｎｔｉｆｉｃａｔｉｏｎｓｙｓｔｅｍ）要求对支持该系统的数据库中的指纹图象数据进行压缩，以提高系统实用性，其恢复图象要求有很高的保真度，以避免丢失细节．同时，在实用系统中，还需要有较快的图象恢复时间．本文总结一种基于对称小波变换的高效模糊指纹图象压缩方法，通过对称快速小波变换，选择适当的分解方式，采用自适应标量量化，加上改进的摘编码，实现高速、高保真的要求．同时，设计一种码率控制策略，有效地控制压缩量．实验结果表明：本文的压缩方法能表现出很好的性能．

A HIGH-PERFORMANCE COMPRESSION METHOD FOR LATENT FINGERPRINT IMAGES BASED ON THE FAST SYMMETRIC WAVELET TRANSFORM

It is usually required that fingerprint images in the database of an AFIS(automated fingerprint identification system) should be compressed to improve its practical performance and also that the restored images should have high fidelity to avoid loss of minutiea while the time consumed in the restoration is required short enough. This paper proposes a high-performance compression method for the latent fingerprint images based on the FSWT(fast symmetric wavelet transform) which meet the requirement of high speed and high fidelity by simultaneously using the FSWT, the proper decomposition style, the adaptive scalar quantization and the improved entropy coding method. Meanwhile a bit rate control strategy is designed to control the compression ratio effectively. The experimental results show that the proposed compression method has high performance.