Image data hiding scheme based on spline interpolation and OPAP

In this paper we propose an image steganography method based on the spline interpolation. Firstly, digital images are often transmitted over the Internet which would arouse little suspicion. Secondly, the high correlation between pixels provides rich space for data embedding; in addition, optimal pixel adjustment procedure (OPAP) is employed to minimise the error between the input image and the output image in order to ameliorate the fidelity of the proposed steganography method. We propose image steganography methods in spatial domain by using a nearest neighbour, bilinear and bicubic spline interpolation technique, which can embed a large amount of secret data into images with imperceptible modification. The interpolation error, which is measured by distance between the maximum value and the predicted value, is used to embed the secret data. The experimental results show that the proposed schemes provide a larger payload and a good image quality.