Watermarking for Multi-resolution Image Authentication

Progressive image transmission (PIT) provides multiple image resolutions that favors a time-critical or a low-band channel environment. In this paper, a PIT based watermarking for multi-resolution image authentication is proposed. The image content with progressive characteristic is taken as the authentication code. The authentication code is then embedded according to multi-resolution image encoding. The experimental results show the validity of the proposed scheme. Malicious operations are detected progressively from multi-resolution images. The significant tampering can be detected firstly and slight tampering is detected in the later authentication stages. Furthermore, the tampered locations can be located correctly.