Parallelization of a color DCT watermarking algorithm using a CUDA-based approach

Image watermarking in DCT domain has a high computational complexity especially for color and high resolution images, where usage of them has been significantly grown. To address this issue, in this article, a data-parallel color DCT watermarking approach is proposed and implemented on GPU using CUDA. Also, in this work, before embedding, the color watermark is compressed using a modified method to get less distortion. CUDA implementation of 8×8 DCT offers 12×–43× speedup with GT 540M and 94×–105× speedup with GTX 580, for different image sizes. In case of embedding procedure, the speedup obtained by GT 540M is between 7× and 26×, and the speedup obtained by GTX 580 is between 46× and 73×, for various case studies. Furthermore, in case of extracting procedure, GT 540M leads to a speedup between 10× and 29×, and GTX 580 leads to a speedup between 75× and 80×, for various case studies.