Embedding Multi-Bit Message in the Joint Time-Frequency Domain

In this paper, we introduce a new multi-bit watermarking method in the joint time-frequency domain. The Wigner distribution for the edges of an image is computed and the time-frequency cells in the Wigner domain that are robust to attacks are used for watermark embedding. The error introduced by the inversion of the watermarked distribution is quantized and used as a key for watermark extraction. The performance of the proposed watermarking algorithm under possible attacks, such as noise, rotation, filtering, and JPEG compression is illustrated