Toward Color Logo Watermark to JPEG2000 Compressed Images

A novel watermark algorithm is proposed for copyright protection of JPEG2000 compressed cultural heritage images in digital museum system. Visually meaningful color logo is encoded as the watermark information. Due to its characteristics, the key problem is to decide how to hide as many bits information as possible into the image while ensuring the information can be retrieved correctly, even after various attacks. In this paper, a new method is proposed to resolve it. For the frequency domain of color logo after Daubechies9/7 wavelet transform, just only low frequency and intermediate frequency coefficient is chosen as the watermark code. In order to ensure both the robust and transparency, intermediate frequency coefficient after Daubechies9/7 wavelet transform is also proposed to embedding watermark code. To achieve the lowest computational cost and provide security, the lifting scheme was presented to implement the wavelet transform. The central contribution of this paper is to develop a watermark algorithm, resilient to like JPEG2000 lossy compression attack and other mainstream attacks, embedding compressed color logo image as watermark and extracting it correctly. Experimental results show that the proposed watermark scheme is computational and quite robust in face of various attacks such as JPEG2000 compression with high compression ratios, filtering, cropping, etc.