Wavelet-based color pathological image watermark through dynamically adjusting the embedding intensity
Summary: This paper proposes a new dynamic and robust blind watermarking scheme for color pathological images based on discrete wavelet transforms (DWTs). The binary watermark image is preprocessed before embedding; firstly it is scrambled by an Arnold cat map and then encrypted by pseudorandom sequence generated by a robust chaotic map. The host image is divided into \(n \times n\) blocks, and the encrypted watermark is embedded into the higher frequency domain of the blue component. The mean and variance of the subbands are calculated, to dynamically modify the wavelet coefficient of a block according to the embedded 0 or 1, so as to generate the detection threshold. We research the relationship between embedding intensity and threshold and give the effective range of the threshold to extract the watermark. Experimental results show that the scheme can resist against common distortions, especially getting advantage over JPEG compression, additive noise, brightening, rotation, and cropping.
scientific article; zbMATH DE number 6123545