This paper presents a robust watermarking approach for hiding gray watermark into digital images. Conventional transform-based watermarking schemes provide only one transform plane for watermark embedding, which makes easy to remove embedded watermark information. Cellular automata transform (CAT) based watermarking scheme can address this problem with CA properties. In this paper, the watermark is first recorded in the form of an elemental image array (EIA) with the computational integral imaging (CII) system, and then the recorded EIA is embedded into the CAT coefficient. The watermark embedding coefficient will be determined by an alpha map which generated by saliency map. This proposed method can provide a more robust watermarking system because EIA is composed of many elemental images and each image has its own property of the watermark. Even though most data of elemental images are lost, the watermark can be reconstructed successfully by using the remaining elemental images. Furthermore, the alpha map which is generated by saliency map can make watermark more invisible for the human visual system. Some experimental results show competence of our system.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering