In this paper, a new oblivious fragile watermarking using discrete cosine transform is
proposed. It is inspired by Wong's public key watermarking scheme proposed in 1998 and
aims to improve its vulnerability towards possible attacks indicated by Barreto and Holliman.
Instead of making use of contextual information and making it an inter-block dependent
scheme, as suggested by Barreto, we adopt another approach to retain its blockwise
independent property. Our scheme can avoid the conditions necessary for such attacks to be
feasible. Furthermore, our scheme extracts the inherent image features and embeds them
into this image as the watermark. This relieves users from having to maintain a database of
watermarks from various sources. Experimental results show that the watermark insertion
procedure has little effect on the visual quality of the watermarked image. They also show
our scheme can locate the modifications made to the watermarked image, including image
scaling, cropping, geometric distortion, pixel value changes, etc.
Relation:
International Journal of Signal Processing, Image Processing and Pattern 2(1):133-140
