Intelligent wavelet domain watermarking of fingerprint images

This paper presents a hybrid intelligent watermarking scheme for securing fingerprint images in the wavelet domain. The proposed method uses an NN-PSO based hybrid approach to secure a person´s fingerprint image by watermarking it with its corresponding face image and demographic information. The input fingerprint image is divided into blocks in the proposed approach and a feed forward neural network is used to calculate the number of bits to be embedded in each image block based on its features. PSO is used to find optimum wavelet coefficients of the image block to be used for watermark embedding in such a way that the quality and minutia matching ability of the host fingerprint are preserved. The experimental study is done on the FVC 2004 fingerprint database and the results show that our hybrid approach gives better results (quality and robustness) than other neural network based and PSO based approaches in the wavelet domain. As the host fingerprint is watermarked with other biometric information of the same person, the proposed work finds application in security implementations based on multimodal biometric authentication.