An improved adaptive QIM watermark iterative algorithm

Quantization Index Modulation (QIM) algorithm is one of the most important blind detection watermarking algorithm. The Adaptive Quantization Index Modulation (AQIM), proposed by I. J. Cox, calculates the quantization step according to the Watson's perceptual model, and makes the embedding steps vary according to the coefficients to be quantized adaptively. It has better reliability and robustness than the traditional Quantization Index Modulation (QIM) algorithm. But in the previous QIM series algorithms, the embedding step(s) during embedding is different from the one(s) in the detection. That results the watermark can't be extracted exactly and integrally even without any attacks/processing. In this paper, an iterative AQIM scheme is proposed to resolve this problem. The simulations also show that the proposed algorithm has better performance than the AQIM algorithm proposed by I. J. Cox.