ABSTRACT: Recently digital image watermarking techniques becomes broadly dependent on mathematics. This paper introduced a proposed scheme using the algebraic matrix decomposition method LU along with two folds Mamdani fuzzy inference system (FIS). The proposed scheme to embedding the watermark into the original image involves two separate cases, one of them splits the original image into 8×8 blocks in order to apply the LUD method on each block and collect the resulted matrices U of each block in one matrix to be ready to the embedding process. Independently, the second case includes computing two values of the FIS according to the two inputs edge sensitivity and contrast sensitivity. The sum of these two values used as a control parameter that decided the robustness of the scheme. The evaluation of the results done by the PSNR and NC which shows that this scheme is robust against various attacks.

Keywords -Fuzzy Inference System, LU decomposition, watermarked image, the Peak Signal to Noise Ratio(PSNR), normalized correlation(NC).