A Novel Multiblock Region-Based Arnold Transformation for Image Watermarking Combined with DWT-PSO Technique

Abstract

To ensure safe transmission of data over the internet, digital watermarking is considered to be most promising technique without compromising any duplication, tampering and copyright infringement of data. Unlike conventional Arnold scrambling method, the proposed method is bounded with two-level security in which blocks are scrambled with one key and simultaneously each block is scrambled at pixel level with second key for the same image which increases the security degree of watermark. Further, the encrypted image is used for digital watermarking which is based on DWT-PSO technique. The system also utilizes PSO algorithm to find out the optimal scaling factor to embed the watermark to obtain the highest possible robustness without failing the transparency. The proposed method's performance against imperceptibility and system robustness is evaluated using PSNR and NCC metrices. The proposed method offers a high PSNR value (54.619 dB), which is sufficient to meet any watermarking scheme's imperceptibility requirements. Furthermore, as compared to the NCC values of other international journals, the proposed method's NCC values are nearly 1 for the majority of the attacks. MATLAB tool is used to simulate the results and it generates better result with respect to imperceptibly and more robust under certain attacks as compared with existing systems.