|
With the growth of digital data, its protection has become a requirement to dissemination it through telecommunication networks. Nowadays, people can easily generate, edit, and share images with their own electronic devices using applications or software to process them. For this reason, in some cases, it is necessary to prove the authenticity of digital images. This paper proposes a semi-fragile color image watermarking scheme for authentication. The proposed scheme embeds EXIF (EXchangeable Image File) metadata of an image as a digital watermark using the LSB method into the Discrete Cosine Transform (DCT) coefficients. EXIF metadata stores relevant information from the image and the digital camera to organize and classify them, such as date, time information, camera settings, and image characteristics. The embedding algorithm is performed by modifying only one mid-frequency coefficient in each eight-by-eight non-overlapped block of the DCT, which offers a significant advantage in reduced processing time. The experimental results demonstrate a watermark imperceptibility according to the objective quality measures PSNR and SSIM values of the watermarked image (43 dB and 0.99, respectively). Additionally, the EXIF metadata can be extracted with 99% accuracy using a completely blind extraction process; it is performed without the original image, original watermark, original camera, or any other derivative information. The simulation results of the proposed method in parallel implementation (multicore CPU and GPU) have shown effective real-time implementation of image watermarking.
|
