Showing papers on "Digital watermarking published in 1970"

A Joint SVD based Watermarking and Encryption Scheme using Chaotic Logistic Map

Abstract: Copyright protection and secrecy of some sensitive data is essential in this present digital era which deals with the advances in cloud computing and big data analytics. Digital watermarking is a popular method for copyright protection whereas cryptography takes care in hiding information as well as for secure transmission of data in a manner that is unreadable to a third party. Combination of both these techniques enhances the security and copyright protection aspects for the concealment of transmitted information. This paper presents a way of achieving those by combining both of these methods together as a joint scheme. Here a robust SVD based algorithm is proposed for embedding a watermark on a host image and then encrypts the resultant stego-image using chaotic logistic map in DCT coefficients. The decryption process is non-blind and requires the help of the key used in encryption. The joint algorithm has been found to be image independent due to its good performance for several popular test images.

A Copyright- and Privacy-Protected Diabetic Retinopathy Diagnosis Network

Abstract: This paper proposes a copyright- and privacyprotected diabetic retinopathy (DR) diagnosis network. In the network, DR lesions are automatically detected from a fundus image by firstly estimating non-uniform illumination of the image, and then the lesions are detected from the balanced image by using level-set evolution without re-initialization. The lesions are subsequently marked by using contours. The lesion-marked fundus image is subsequently shared for intra or inter hospital network diagnosis with copyright and privacy protection. Watermarking technique is used for image copyright protection, and visual encryption is used for privacy protection. Sign scrambling of two dimensional (2D) discrete cosine transform (DCT) and one dimensional (1D) DCT is proposed for lesion-marked fundus image encryption. The proposed encryption methods are compared with other transform-based encryption methods, i.e., discrete Fourier transform (DFT) amplitude-only images (AOIs), DCT AOIs, and JPEG 2000-based discrete wavelet transform (DWT) sign scrambling which were proposed for image trading system. Since the encryption is done after DR diagnosis, contours used for DR marking must also be visually encrypted. The proposed encryption methods are effective for strong-edge images that are suitable for lesion-marked fundus images, while random sign-based JPEG 2000, DFT AOIs, and DCT AOIs encrypt the images imperfectly. Moreover, the proposed methods are better in terms of image quality. In addition, watermarking performance and compression performance are confirmed by experiments.

Blind Scheme with Histogram Peak Estimation for Histogram Modication-Based Lossless Information Embedding

Abstract: In this paper, a simple scheme for histogram modification-based lossless information embedding (HM-LIE) is proposed. The proposed scheme is free from memorizing side information, i.e., blind. A HMLIE scheme modifies particular pixel values in an image in order to embed information in it on the basis of its histogram, i.e., tonal distribution. The scheme recovers the original image as well as extracts embedded information from a distorted image conveying embedded information. Most HM-LIE schemes should memorize a set of image-dependent side information per image. The proposed scheme does not have to memorize such information to avoid costly identification of the distorted image carrying embedded information because of the introduction of two mechanisms. One is estimating side information on the basis of a simple statistic, and the other is concealing not only main information but also a part of the side information in the image. These approaches make the proposed scheme superior to the conventional blind schemes in terms of the quality of images conveying embedded information.