Invisible Watermarking on Grayscale Image

Abstract

Digital watermarking is a procedure to embedded watermark or logo into an image to avoid copyright and protect the image from being manipulated by others without owner approval. In the Technical and Vocational Education and Training (TVET) sector, the main challenge in watermarking is how to achieve high imperceptibility or visual quality and robustness without sacrificing the capacity of the cover image. In addition, the watermark should be ably extracted without any distortion. As for that, spiral scan embedding technique is used to overcome this issue. The performance of the proposed project is evaluated by comparing the results of extracting process using spiral scan technique with sequence technique, while the imperceptibility of the cover image is measured using Peak Signal Ratio (PSNR) and robustness of the watermarked image is measured using Normalized Cross Correlation (NCC). The eesult shows that the proposed technique obtains high imperceptibility and robustness.