Parallel color image watermarking scheme for multiple picture object based on multithreading coding

Abstract

In this paper, a novel parallel color image watermarking scheme in the frequency domain for copyright protection of Multiple Picture Object (MPO) based on multithreading coding is proposed. Designed technique consists of three steps: firstly, the color watermark is codified using the Curvelet Transform (CvT), reducing quantity of information that represents the watermark; the second step represents the embedding process of a color watermark. In the embedding process, theMPO file contains two images where each image is divided in 8x8 pixels blocks applying DCT to any block. A color watermark is inserted in the medium frequency sub-bands of each DCT block, because the modifications performed in this sub-band are less perceptible by Human Visual System (HVS). Finally, during third step, the recovering process for color watermark is performed. The proposed scheme appears to demonstrate significant improvement in processing time though possible parallelization process when moving from serial programming to the use of threads in multicore CPUs. According to numerous experiments, where the Peak Signal-to-Noise Ratio (PSNR) and Similarity Structural Index Measure (SSIM) were used as quality criteria for watermarked MPO image and the recovered color watermark, novel method is not intrusive, since it does not degrade the quality of the watermarked MPO image. Additionally, the proposed framework is resistant to the most common image processing attacks.