Adaptive image data hiding using transformation and error replacement

Watermarking is popular method for effective copyright protection of digital data. The invisible image watermarking is a type of watermarking which is used to conceal secret information in a cover image. In any watermarking system, there is a trade-off between imperceptibility and payload of the data to be hidden in the cover medium. Therefore, only a limited amount of data can be concealed in the cover image while watermark remain imperceptible. This paper proposes a new method of adaptive blind digital image data hiding in Discrete Cosine Transform (DCT) domain using Minimum Error Lease Significant Bit Replacement (MELSBR) method and Genetic Algorithm (GA). In the proposed method, the secret image is embedded into the DCT transformed cover image. Initially, the host and the secret image both are partitioned into equal sized blocks. Then for each secret image block, host image block is intelligently selected through GA and is embedded using MELSBR method. GA helps in identifying the target cover image blocks such that with the LSB embedding, both visual quality of the cover image and imperceptibility of the secret image remain least affected. In watermark extraction process, the watermarked image is decomposed into equal sized blocks and then using the Jigsaw Puzzle Solver (JPS) the secret image is reconstructed. In spite of doubling the payload of the data to hide, the experimental results have shown better imperceptibility and robustness results of the proposed method as compared to the current approaches in this domain.