Partial Reversible Data Hiding with High Stego-image Quality and Embedding Capacity
| Autor: | Song-Yu Wu, 吳嵩裕 |
|---|---|
| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Data hiding (DH) technology is an important research field that combines cryptography and digital multimedia processing. DH can be widely used in multimedia, especially digital images. Error correcting code (ECC) based DH can is increase embedding capacity, and meanwhile reduce the number of modified bits. Up to present, there were many researches on ECC based DHs, e.g., using Hamming code, BCH code, and Golay code. Some of these DHs are the reversible data hiding (RDH). RDH allows the recipient for extracting secret data and meantime restore the original cover media. Recently, Jana et al. proposed a partial RDH (PRDH) based on (7, 4) Hamming code. Their scheme deals with three images: the original image (OI), the cover image (CI), and the stego image (SI). The CI is generated by slightly modifying OI (both OI and CI have almost the same image quality). After that, one can embed secret into CI to generate SI. The so-called partial reversible capability is that we can reconstruct the CI without distortion. However, in Jana et al.’s PRDH, the authors only adjust redundant bits by using (7, 4) Hamming code with even (or odd) parity. This simple approach may modify 3 redundant bits at most in 7 least significant bit (LSBs) for generating CI from OI, and this degrades the CI quality seriously. In this thesis, we construct two schemes: the proposed PRDH (PPRDH) and the modified PRDH (MPRDH). PPRDH enhances the partial reversible property that improves the visual quality of CI. On the other hand, MPRDH enhances PPRDH to achieve the high embedding capacity. Theoretical estimations of average mean square errors for these PRDH schemes are given to demonstrate the advantage of our PRDH schemes. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|