Low bit rate compression of fingerprint images for maintaining or improving verification performance

In this paper we propose a fingerprint image compression method based on the wavelet transform and SPIHT coder. The proposed method employs the proposed technique of dynamic range reduction which benefits from the bimodality of fingerprint images in order to improve the compression efficiency. In addition, we utilized some image enhancement techniques to alleviate the leakage effect as well as further improve the compression efficiency. We have investigated the impacts of compression on recognition efficiency of compressed images. In this investigation we proposed two new measures of breakdown point and downfall slope based on the recognition accuracy curve versus compression bit rate, in order to evaluate the fingerprint image compression approaches more sophisticatedly.
Experimental results show that the proposed technique of dynamic range reduction decreased the breakdown point by 0.05 bpp in average. The proposed image enhancement techniques improved the recognition accuracy up to 5% at all compression bit rates higher than the breakdown point. It also decreased the downfall slope. Regarding the PSNR performance, the proposed method outperformed the JPEG2000 and WSQ approaches by 0.8 dB, in average.