Hiding secret data in images via predictive coding

This paper presents a prediction-based image-hiding scheme that embeds secret data into compression codes during image compression. This scheme employs a two-stage structure: a prediction stage and an entropy coding stage. The secret data is embedded into the difference values of a given image after the prediction stage is performed. According to the experimental results, the image quality is better than Jpeg–Jsteg and its improved scheme (Inform. Sci. 141 (1–2) (2002) 123). The average image quality of the stego-images in the proposed scheme is greater than 50 dB when the hiding capacity is 1 bit per pixel, whereas those values in Jpeg–Jsteg and scheme in Chang et al. (Inform. Sci. 141 (1–2) (2002) 123) are 37.04 and 33.73 dB, respectively. The hiding capacity of the proposed scheme is 65,536 bits when the hiding capacity is 1 bit per pixel, whereas it is 53,248 bits in scheme (Inform. Sci. 141 (1–2) (2002) 123) and less than 3000 bits in Jpeg–Jsteg. 2004 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.