Classification-based Image Watermarking Using Rank Order in the Wavelet Domain

Abstract

In this paper, we propose a novel digital watermarking technique called Classification-based Image Watermarking using Rank Order in the Wavelet domain (CIWROW) for gray-level images. Due to WT (Wavelet Transform) having the characteristics of using both spatial and frequency resolutions, it can be effectively used to approximate target functions. Several relationships among the subbands in wavelet domain are explored and then employed to designate a classification algorithm using rand order for all wavelet blocks of an image. During watermark embedding, the target blocks to be watermarked are embedded by different methods according to which class the blocks belong to. The CIWROW technique retrieves watermarks without the original images. Finally, experimental results are included in this paper to illustrate that the performance of the CIWROW technique is acceptable. Furthermore, the CIWROW technique is rather robust to be immune against basic image-processing attacks.