A rewritable data embedding in JPEG-XR compressed image with file size preservation

In this paper, we propose a rewritable data embedding method in the JPEG-XR compressed domain. Our proposed method is based on modifying the sign of the selected FCT (Forward Core Transform) coef- ficients. Specifically, the last coefficient, with respect to the conventional zigzag scanning order, in a 4 x 4 HP block is selected to embed data. Af- ter extracting the embedded data, the proposed method can restore the image quality by using the proposed simple majority vote method. Al- though the restoration does not perfectly regenerate the original image, the proposed data embedding method is rewritable. To evaluate the pro- posed method, four criteria including quality of the output image (i.e., embedded with data), file size of the output image, available payload and reconstructed image quality, are considered. Experiments are carried out to verify the basic performance of the proposed method. In the best case scenario, the proposed method can embed up to 15954 bits into an 8-bit grayscale image of dimension 512x 512 pixels with a reconstructed image of SSIM = 0.9919.