Multiple-watermarking scheme of the European Article Number Barcode using similar code division multiple access technique

The code division multiple access technique is widely used in digital communication systems. In this paper, a mix codec, hamming codec, and spread spectrum technique construct a similar code division multiple access (SCDMA) structure. It is used to configure a multiple-watermarking scheme for still images. Meanwhile, another type of multiple-watermarking scheme, a non-code division multiple access (NCDMA) watermarking structure, is used to demonstrate that the SCDMA structure is superior. In the embedding process, three watermark bit-streams are modulated to the bit-stream of the SCDMA code. Successively, the SCDMA code stream is concealed into three coefficient pairs of each DFT block by an adaptive phase shift keying (APSK) modulation.The barcode has several advantages: it is not as easily worn down as the magnetic card; it has a very low rate of error; and it is very cheap and easy to be fabricate. Therefore, we use the barcode pattern to generate the watermarks to enhance the effect of the digital rights management. Compared to other multiple-watermarking schemes, our proposed method has two advantages: (1) the secret image has very high security by using SCDMA and APSK as in digital communication; and (2) the extracted watermarks have the same quality even under all kinds of attacks, which is better than other schemes with different extracted watermark quality.