This letter presents a lossless data hiding scheme for digital images which uses an edge detector to locate plain areas for
embedding. The proposed method takes advantage of the well-known gradient adjacent prediction utilized in image coding.
In the suggested scheme, prediction errors and edge values are first computed and then, excluding the edge pixels, prediction
error values are slightly modified through shifting the prediction errors to embed data. The aim of proposed scheme is to
decrease the amount of modified pixels to improve transparency by keeping edge pixel values of the image. The experimental
results have demonstrated that the proposed method is capable of hiding more secret data than the known techniques at the
same PSNR, thus proving that using edge detector to locate plain areas for lossless data embedding can enhance the
performance in terms of data embedding rate versus the PSNR of marked images with respect to original image.