Digital Watermarking Menggunakan Metode Discrete Cosine Transform

Abstract

Due to good randomness and easy reproduction of chaos, the watermark is firstly permuted by the hashed chaotic sequence. Then a small number of reference points are randomly selected in the middle frequency bands of the DCT domain based on the chaotic sequences. After that, the batch-type of disorder watermark bits are embedded into the neighborhood of every reference point using odd-even quantization. The usefulness of multilevel chaotic keys and privacy of modification to frequency coefficients enhance the security of watermark information.