Showing papers on "Digital watermarking published in 1995"

Techniques for data hiding

Abstract: Data hiding is the process of embedding data into image and audio signals. The process is constrained by the quantity of data, the need for invariance of the data under conditions where the `host' signal is subject to distortions, e.g., compression, and the degree to which the data must be immune to interception, modification, or removal. We explore both traditional and novel techniques for addressing the data hiding process and evaluate these techniques in light of three applications: copyright protecting, tamper-proofing, and augmentation data embedding.

Cryptology for digital TV broadcasting

Abstract: Digital TV broadcasting needs new cryptological tools for conditional access, copyright protection and image authentication. The aim of this paper is to overview the corresponding systems' features. The description of a conditional access system is given. It is shown that equitable systems need the use of a trusted third party. The design of efficient copyright protection by watermarking images and image authentication by signatures are also briefly discussed. >

Watermarking digital images for copyright protection

Abstract: A watermark is all invisible mark placed on an image that can only be detected when the image is compared with the original. This mark is designed to identify both the source of a document as well as its intended recipient. This paper discusses various techniques for embedding such marks in grey scale and colour digital images. It begins specifying the requirements that an effective image watermarking scheme must possess, followed by a review of current and novel techniques based on image transforms.

Method and apparatus for the addition and removal of digital watermarks in a hierarchical image storage and retrieval system.

Abstract: An image processing technique is described in the context of a hierarchical image storage and retrieval system. The method allows for the controlled addition and removal of digital watermarks from selected image components in the hierarchy. The method adds a digital watermark in a selected image resolution component and the means to remove it in an additional image component termed the watermark removal component. The method employs the encryption of the watermark removal component, and decryption with a special key, or password during authorized retrieval. This technique allows users of a distributed system the convenience of providing the entire image hierarchy on a single storage medium permitting images containing watermarks to be accessed without restriction for browsing and proofing, while the watermark removal requires knowledge and us of a controlled code.

Equitable Conditional Access and Copyright Protection for Image Based on Trusted Third Parties

Abstract: Image communication needs new cryptological tools for conditional access, copyright protection and image authentication. The aim of this paper is to overview the corresponding systems' features. The design of efficient copyright protection by watermarking images and image authentication by signatures is also briefly discussed. It is shown that equitable systems need the use of a Trusted Third Party, and a possible solution is presented. The implementation of this new function in the multimedia world strongly differs from that in the Electronic Data Interchange environment where it is already well known. This difference will also be detailed.

Method and equipment for adding and deleting digital watermark in hierarchical picture memory and fetch system

Abstract: PURPOSE: To allow a low-resolution image to be directly fetched and, at the same time, to prevent the utilization of a high-resolution image without authentication by storing low-resolution digital images and high-resolution digital images encoded with watermarks on a recording medium. CONSTITUTION: On a digital recording medium 10, 1/16-base images, 1/4-base images, and base images with watermarks are recorded in a non-encrypting form. The base images with watermarks are formed by assembling watermarks to the base images by means of a watermark inserter 22 of watermark inserting section 34. Base images from which watermarks are to be removed are encrypted by means of a data encrypting device 26 through an encoder 20 and recorded on the medium 10. At the time of preparing a list or performing trial printing, therefore, the images with watermarks can be accessed without limitation and, at the same time, the high-resolution images from which watermarks are removed can be obtained by inputting a decoding key.

Thematic processing and retrieving of watermarks

Abstract: This paper presents an application of digital image processing in the historical sciences it deals with the processing of x-ray recordings of watermark images taken from Middle Ages codices A sequence of processing steps for image enhancement, geometrical transformations, watermark extraction,a nd binarization is suggested The watermarks are stored together with alphanumeric information in a database, allowing the historian to retrieve and compare watermarks and to measure parameters of watermarks such as height, length, distance between special points, and radii© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering Downloading of the abstract is permitted for personal use only