Abstract: In order to improve the imperceptibility and robustness of the digital image with watermark, a watermark embedding scheme based on image information entropy and edge entropy theory combined with fruit fly optimization algorithm is proposed. Firstly, the carrier image is divided into blocks, and the information entropy and edge entropy of each block are calculated. The two entropy values of each block are added and sorted. Then, the blocks with higher entropy value are selected according to the capacity of embedded watermark, and each bit of watermark is embedded into the blocks which are decomposed by wavelet transform and singular value. Finally, in order to further balance the contradiction between the transparency and robustness of the embedded watermark, the intensity of the embedded watermark is optimized by using the fruit fly algorithm. The experimental results show that the proposed method has better imperceptibility and is more robust than similar algorithms in the face of multiple types and intensity of simulated attacks.

Key words: information entropy, edge entropy, fruit fly optimization, digital watermark, embedding intensity