Inpainting-assisted reversible authentication method for demosaiced image with enhanced recoverability

Modern image capture devices typically incorporate a Color Filter Array (CFA) to separate primary light colors for image capture. After undergoing demosaicing processing, the resulting image, known as a demosaiced image, comprises sampled and rebuilt components. Recent research has been concentrated on detecting tampering in demosaiced images, yet current methods face challenges when dealing with larger tampered areas, resulting in incomplete or rough recovery. This paper introduces a recoverable demosaiced image authentication technique. It extracts recovery codes from sampled components using the adaptive adjustment technique and embeds them into the rebuilt components through adaptive embedding. Authentication codes are calculated and embedded into the least significant bits of the rebuilt components. After authentication, tampered areas can be restored using recovery codes, while unrecoverable parts are repaired using image inpainting. If the marked image is untampered, the CFA image can be extracted to restore the original demosaiced image. Compared to previous state-of-the-art methods, our approach achieves a noticeable improvement in visual quality when repairing tampered areas that cover over 50% of the image.