New Framework for Code-Mapping-based Reversible Data Hiding in JPEG Images

Code mapping (CM) is an efficient technique of reversible data hiding (RDH) in JPEG images, which embeds data by constructing the mapping relationship between used codes and unused codes in JPEG bitstream. In this paper, we present a new framework to design the CM-based RDH method. Firstly, to suppress the file size expansion and improve the applicability, a new code mapping strategy is proposed. Based on the proposed strategy, the mapped codes are redefined by customizing a new Huffman table thoroughly rather than selected from the unused codes in the original Huffman table. Afterwards, the key issue of designing the CM-based RDH method, i.e., constructing the code mapping, is converted into solving a combinatorial optimization problem. As a realization, a novel CM-based RDH method is introduced by employing the genetic algorithm (GA). Experimental results show that the efficacy of the proposed method with high embedding capacity and no signal distortion while suppressing file size expansion

A digital signature and watermarking based authentication system for JPEG2000 images

In this thesis, digital signature based authentication system was introduced, which is able to protect JPEG2000 images in different flavors, including fragile authentication and semi-fragile authentication. The fragile authentication is to protect the image at code-stream level, and the semi-fragile is to protect the image at the content level. The semi-fragile can be further classified into lossy and lossless authentication. With lossless authentication, the original image can be recovered after verification. The lossless authentication and the new image compression standard, JPEG2000 is mainly discussed in this thesis

WG1N5315 - Response to Call for AIC evaluation methodologies and compression technologies for medical images: LAR Codec

This document presents the LAR image codec as a response to Call for AIC evaluation methodologies and compression technologies for medical images.This document describes the IETR response to the specific call for contributions of medical imaging technologies to be considered for AIC. The philosophy behind our coder is not to outperform JPEG2000 in compression; our goal is to propose an open source, royalty free, alternative image coder with integrated services. While keeping the compression performances in the same range as JPEG2000 but with lower complexity, our coder also provides services such as scalability, cryptography, data hiding, lossy to lossless compression, region of interest, free region representation and coding

WAVELET BASED DATA HIDING OF DEM IN THE CONTEXT OF REALTIME 3D VISUALIZATION (Visualisation 3D Temps-Réel à Distance de MNT par Insertion de Données Cachées Basée Ondelettes)

The use of aerial photographs, satellite images, scanned maps and digital elevation models necessitates the setting up of strategies for the storage and visualization of these data. In order to obtain a three dimensional visualization it is necessary to drape the images, called textures, onto the terrain geometry, called Digital Elevation Model (DEM). Practically, all these information are stored in three different files: DEM, texture and position/projection of the data in a geo-referential system. In this paper we propose to stock all these information in a single file for the purpose of synchronization. For this we have developed a wavelet-based embedding method for hiding the data in a colored image. The texture images containing hidden DEM data can then be sent from the server to a client in order to effect 3D visualization of terrains. The embedding method is integrable with the JPEG2000 coder to accommodate compression and multi-resolution visualization. Résumé L'utilisation de photographies aériennes, d'images satellites, de cartes scannées et de modèles numériques de terrains amène à mettre en place des stratégies de stockage et de visualisation de ces données. Afin d'obtenir une visualisation en trois dimensions, il est nécessaire de lier ces images appelées textures avec la géométrie du terrain nommée Modèle Numérique de Terrain (MNT). Ces informations sont en pratiques stockées dans trois fichiers différents : MNT, texture, position et projection des données dans un système géo-référencé. Dans cet article, nous proposons de stocker toutes ces informations dans un seul fichier afin de les synchroniser. Nous avons développé pour cela une méthode d'insertion de données cachées basée ondelettes dans une image couleur. Les images de texture contenant les données MNT cachées peuvent ensuite être envoyées du serveur au client afin d'effectuer une visualisation 3D de terrains. Afin de combiner une visualisation en multirésolution et une compression, l'insertion des données cachées est intégrable dans le codeur JPEG 2000

RDH in Image with Asymmetric Key Cryptography

Reversible Data Hiding technique (RDH) is an approach to embed secret data into the encrypted original cover image. The confidentiality must be there when the secret media is transmitted to the receiver via network. This paper proposes a new framework for embedding the secret data into the image with the combination of RDH technique with asymmetric key cryptography to gain high security. It achieves perfect extraction of data and quality original image retrieval on decryption process. Thus this system will gain maximum efficiency and maintain high secrecy for both data and image than the existing RDH systems

Hiding Text within LSB of Image Pixels

Data security is maintained by assuming the consistency and accuracy of data over its entire life cycle. Security aspects come into play when it is necessary or desirable to protect the information transmission from an opponent who may present a threat to confidentiality, authenticity, data integrity and denial of service. Here, we are proposing a separable reversible data hiding technique in which data to be hidden is text. This technique proposed a way how to hide large amount of text behind an image. Process involves creating space after compressing least significant bits of the image. Later, the data is hidden in this space

GABUNGAN ALGORITMA JPEG DAN WATERMARKING UNTUK MENINGKATKAN KULITAS DAN RATIO KOMPRESI

Format JPEG merupakan model kompresi citra warna yang telah ditetapkan sebagai standar internasional ISO dan telah umum dipakai. Teknik kompresi JPEG diawali oleh proses RGB to YCbCr colour transformation, kemudian masing-masing komponen warna Y, Cb dan Cr akan dikompresi melalui proses Discrete Cosine Transform (DCT), Quantizing dan Coding secara berturut-turut. Bit-bit hasil coding dari masing-masing komponen warna Y, Cb dan Cr digabung menjadi satu kesatuan secara berurutan. Paper ini menguraikan suatu teknik kompresi yang dapat lebih mengoptimalkan hasil kompresi JPEG melalui penyisipan bit-bit hasil coding dari satu komponen warna kedalam matriks hasil kuantisasi dari komponen warna lainnya. Hasil uji coba menunjukkan bahwa dengan kualitas kompresi (PSNR) yang sama, teknik kompresi yang dikembangkan dalam paper ini memiliki rasio kompresi antara 10.99% sampai 154% lebih baik dari JPEG yang digunakan dalam sejumlah perangkat lunak. Demikian pula untuk nilai rasio kompresi yang sama, teknik ini memberikan kualitas kompresi yang lebih baik. Keyword: Kompresi citra, JPEG, Watermarking, MI