A watermarking algorithm

A watermarking algorithm based on the concepts of the JPEG quantization and absolute value is introduced in this paper. The JPEG is a usually file format for transmitting the digital content on the network. Thus, the one of the basic demands for the robustness in the watermarking technique is able to resist the JPEG attack. Nevertheless, there is a question that is the two similar DCT coefficients will be quantified to the same rank in JPEG quantification process. This question will more or less cause the error of the extracting watermark from the watermarked image with lossy compression. In this paper, we propose the watermarking technique to improve the mistake as discuss above in order to decrease the bit error rate (BER) of the retrieve watermark. And, the concept of the absolute value is used to raise the peak signal noise rate (PSNR) of the watermarked image. Addition, the idea of optimum is adopted to trade-off the qualities between the watermarked image and the retrieve watermark. With this technique, the survive when the watermarked image is compressed using JPEG. Moreover, the proposed scheme doesn't need the information of the watermark and the original host image in the extracting process.