Tchebichef Image Watermarking based on PN-Sequence

In the modern era, sharing and distribution of digital data over the internet have increased significantly. This makes it easier to duplicate data, even though not all data may be duplicated without permission because it has copyright. Image watermarking is the most popular solution for protecting copyright in digital images. The way to embed copyright is generally by transforming the image into the frequency domain, which in this way proves that copyright embedding is more resistant to various attacks. Discrete Tchebichef transform (DTT) is a domain transformation that has advantages in computational speed, is low in complexity and can reduce memory usage and has properties similar to discrete cosine (DCT) transformations. DCT is the most popular transformation to be developed, wherein one of the studies using the PN Sequence combined with DCT at the time of the embedding process, it was proven to improve imperceptibility quality. However, the increase in imperceptibility generally makes watermark resistance less. Based on this hypothesis the research aims to implement a watermark embedding scheme with PN Sequence on DTT to obtain a watermarking scheme that produces better imperceptibility and keeps the quality of watermark resilience against various manipulations. Based on the results of testing and measurement using PSNR, it is evident that the imperceptibility quality rises around 3dB. Watermark resistance testing for attacks also proves that using the proposed scheme but can maintain watermark resistance.