A block-based watermarking using wavelet coefficients

This paper proposed a block-based watermarking method using wavelet transform coefficients. The coefficients were separated into blocks and a watermark was embedded into these 3×3 blocks size. Each block can be loaded maximum 9 bits of payload. The wavelet coefficients in a block will be changed randomly to insert a payload. The inverse transformation of the watermarked image is similar with the embedding watermark. An experimental result will be shown to analyze the robustness from any kind of attacks.