Digital Image Watermarking With Random Selection of Watermark Insertion Having Adaptive Strength

We have presented an algorithm of digital image watermarking for gray scale images which we implemented in frequency domain. Before inserting the watermark, we added the Hamming codes row wise as well column wise. Two encryption techniques were implemented on the ECC inserted watermark for its security. The pixel position for inserting the watermark was calculated using starting row and column number for that 8×8 block. Pixel embedding strength is calculated using criteria that low frequency is robust in general signal processing attacks, thus choosing less value to be embedded and vice-versa. Results show that the watermarking algorithm is robust against common signal processing attacks. The algorithm is tested against multiple attacks also.