A scheme of oblivious ghost-watermarking based on cepstral analysis and correlation techniques

This paper proposes a new scheme of oblivious ghost-watermarking based on cepstral analysis and correlation techniques. First we formulate the signal of a composite image which consists of original and single-ghost components. Next we describe the definition of power cepstrum for the composite image. To improve the cepstral performance, we introduce a cepstral difference between composite and original images and examine its properties. After that, we explain two types of basic algorithms for the oblivious ghost-watermarking. The experimental results for some test images (M-sequence ghost images) show that the watermark information in each image can be detected sensitively by our scheme even when the ghost images are compressed.