As a major method for intellectual property right protecting, digital watermarking techniques have been widely studied
and used. But due to the problems of data amount and color shifted, watermarking techniques on color image was not so
widespread studied, although the color image is the principal part for multi-medium usages. Considering the
characteristic of Human Visual System (HVS), an adaptive color image watermarking algorithm is proposed in this paper.
In this algorithm, HSI color model was adopted both for host and watermark image, the DCT coefficient of intensity
component (I) of the host color image was used for watermark date embedding, and while embedding watermark the
amount of embedding bit was adaptively changed with the complex degree of the host image. As to the watermark image,
preprocessing is applied first, in which the watermark image is decomposed by two layer wavelet transformations. At the
same time, for enhancing anti-attack ability and security of the watermarking algorithm, the watermark image was
scrambled. According to its significance, some watermark bits were selected and some watermark bits were deleted as to
form the actual embedding data. The experimental results show that the proposed watermarking algorithm is robust to
several common attacks, and has good perceptual quality at the same time.