Robust distance-based watermarking for digital image

• In this paper, an algorithm is developed to invisibly watermark a cover object (color image) using watermark object (iconic image). The algorithm is based on the distances among the addresses of values of the cover object. These distances use to make the embedding. The order of manipulating these distances are specified by the values of the watermark data which is dealt with serially. The algorithm serves and achieves self encryption key. Each watermark object has its unique pattern of distances at different possible lengths of distance bits. This enhances the complexity of sequential embedding. The algorithm is tested using direct and single level and double level of Two-Dimensional Discrete Wavelet Transform (2D DWT) embeddings. Two important issues are addressed. Firstly is to achieve a high Peak Signal to Noise Ratio (PSNR). The ratio was found to increase with an increasing of distance bits. Secondly is that the watermarked object retains the same properties of cover object. The algorithm shows resisting and withstanding against the most important attacks. Some of these include the lossy compression, blurring, resize and some types of Noise.

Nyckelord

2D DWT and attacks

Cover object

Distance bits

Watermark object

Watermarked object

Algorithms

Cryptography

Digital watermarking

Discrete wavelet transforms

Signal to noise ratio

Watermarking

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