TPE Optimization Algorithm Combined With Reversible Information Hiding

Privacy issues may arise after uploading images to image hosting platforms.With traditional image encryption,content-rich and meaningful images are converted into noise-like encrypted images,which protects against privacy violations but at the expense of visual usability.In recent years,Thumbnail-Preserving Encryption(TPE)has been proposed to balance privacy and visual usability by preserving thumbnails unchanged after encryption.However,existing reversible data hiding technologies are difficult to be applied to TPE,making TPE only visually usable without the availability of additional information.To address this,this paper proposes a TPE scheme that is compatible with additional information availability.The existing reversible data hiding techniques are often performed in pixel point units,which is not compatible with TPE which is encrypted in block units.Therefore,this paper makes adaptive modifications to the data hiding technique,making it organically integrated with the TPE scheme,so that the TPE scheme can achieve the hiding and extraction of data.Overall,this paper combines the traditional TPE encryption scheme with the reversible information hiding technique to achieve compatibility between the visual availability of ciphertext images and the availability of additional information,and experimentally verifies that the proposed scheme in this paper can perform reversible information hiding while maintaining thumbnails with little damage to the image quality.The details of this paper contain the following aspects:(1)Reversible data hiding in thumbnails is achieved using histogram-based reversible information hiding technology.Since the thumbnail remains unchanged before and after encryption of the image by TPE,resulting in the histogram accompanying the thumbnail does not change,information hiding can be performed using the histogram of the thumbnail to achieve embedding and extraction of information at any stage before and after encryption.(2)The relationship between the TPE scheme and reversible data hiding is investigated in depth,and a TPE optimization scheme that integrates with reversible data hiding is proposed.Thumbnails cannot exist independently,so after embedding information in thumbnails,they need to be mapped back to the corresponding images,which requires targeted processing of images to make them able to carry information and ensure the correctness of embedding.(3)In this paper,the usability of TPE is extended to enable ciphertext images to embed information,achieving not only visual usability,but also the usability of embedded information.The experimental results show that the proposed scheme protects privacy and embeds additional information while comparing with existing schemes in terms of image quality,information embedding usability,and robustness.