Hiding Facial Information in Color Image

In this paper, we introduce two schemes for color images (including gray scale fingerprint images) watermarking, which can embed facial information of a user into his/her passport or ID card image. Our first scheme is an improvement of Hsu´s method to embed information in gray scale and color images. The other scheme applies CPT algorithm to matrixes gathered by least significant bit (lsb) for watermarking. The embedded data that can be referred to as the digital signature is the features of a face image that is often known as facial information. Compared with the prior works in color images watermarking, our first method not only preserves the quality of reconstructed face image but also decreases the pixel- changed ratio during the embedding process. Our second method can hide a large number of data bits without any significant quality change of host image. To enhance the authentication and security while transferring via the Internet, a public key cryptosystem was used to protect the secret key. Experimental results of color images watermarking using our two methods are also included.