Image-to-Tree to Select Significant Blocks for Image Watermarking
In this paper, we propose a robust watermarking image approach that focuses on a serious problem in image watermarking which consists on finding a compromise between the authentication and the computational complexity aspects in watermark embedding/extracting processes. The approach is based on the choice of the adequate DC components per block for a given image after applying a frequency transform by DCT (Discrete Cosine Transform) on each block. The DC blocks of the entire image will be represented by a tree passing through blocks having a higher texture to ensure imperceptibility of the embedded watermark. The watermarking process is applied directly in the spatial domain that guarantees a less computation complexity on a particular set of blocks having high texture. It is noted that the proposed approach guarantees very remarkable watermark imperceptibility compared to other approaches operating in the same domain. The approach was tested against several geometric and non-geometric attacks. Similarly, the attacked watermark against most known dangerous attacks are recovered. The results obtained with regard to watermark extraction against several attacks are very encouraging and discussed in this paper.