Taming Reversible Halftoning via Predictive Luminance

Traditional halftoning usually drops colors when dithering images with binary dots, which makes it difficult to recover the original color information. We proposed a novel halftoning technique that converts a color image into a binary halftone with full restorability to its original version. Our novel base halftoning technique consists of two convolutional neural networks (CNNs) to produce the reversible halftone patterns, and a noise incentive block (NIB) to mitigate the flatness degradation issue of CNNs. Furthermore, to tackle the conflicts between the blue-noise quality and restoration accuracy in our novel base method, we proposed a predictor-embedded approach to offload predictable information from the network, which in our case is the luminance information resembling from the halftone pattern. Such an approach allows the network to gain more flexibility to produce halftones with better blue-noise quality without compromising the restoration quality. Detailed studies on the multiple-stage training method and loss weightings have been conducted. We have compared our predictor-embedded method and our novel method regarding spectrum analysis on halftone, halftone accuracy, restoration accuracy, and the data embedding studies. Our entropy evaluation evidences our halftone contains less encoding information than our novel base method. The experiments show our predictor-embedded method gains more flexibility to improve the blue-noise quality of halftones and maintains a comparable restoration quality with a higher tolerance for disturbances.Comment: to be published in IEEE Transactions on Visualization and Computer Graphic

A New Digital Watermarking Algorithm Using Combination of Least Significant Bit (LSB) and Inverse Bit

In this paper, we introduce a new digital watermarking algorithm using least significant bit (LSB). LSB is used because of its little effect on the image. This new algorithm is using LSB by inversing the binary values of the watermark text and shifting the watermark according to the odd or even number of pixel coordinates of image before embedding the watermark. The proposed algorithm is flexible depending on the length of the watermark text. If the length of the watermark text is more than ((MxN)/8)-2 the proposed algorithm will also embed the extra of the watermark text in the second LSB. We compare our proposed algorithm with the 1-LSB algorithm and Lee's algorithm using Peak signal-to-noise ratio (PSNR). This new algorithm improved its quality of the watermarked image. We also attack the watermarked image by using cropping and adding noise and we got good results as well.Comment: 8 pages, 6 figures and 4 tables; Journal of Computing, Volume 3, Issue 4, April 2011, ISSN 2151-961

Survey on Reversible Data Hiding in Encrypted Images Using POB Histogram Method

This paper describes a survey on reversible data hiding in encrypted images. Data hiding is a process to embed useful data into cover media. Data invisibility is its major requirement. Data hiding can be done in audio, video, image, text, and picture. Here use an image for data hiding especially digital images and existing method (Histogram Block Shift Base Method) HBSBM or POB. Now a day's reversible data hiding in encrypted images is in use due to its excellent property which is original cover image can be recovered with no loss after extraction of the embedded data. Also, it protects the original data. According to the level and kind of application one or more data hiding methods is used. Data hiding can be done in audio, video, text, and image and other forms of information. Some data hiding techniques emphasize on digital image security, some on the robustness of digital image hiding process while other's main focus is on imperceptibility of a digital image. The capacity of digital information which has to hide is also the main concern in some of the applications. The objective of some of the papers mentioned below is to achieve two or more than two parameters i.e. Security, robustness, imperceptibility and capacity but some of the parameters are trade-off which means only one can be achieved on the cost of other. So the data hiding techniques aiming to achieve maximum requirements i.e. security, robustness, capacity, imperceptibility etc. and which can be utilized in the larger domain of applications is desired. Related work for techniques used for data hiding in a digital image is described in this paper

A Self Recovery Approach using Halftone Images for Medical Imagery System

ABSTRACT Security has become an inseparable issue even in the field of medical applications. Communication in medicine and healthcare is very important. The fast growth of the exchange traffic in medical imagery on the Internet justifies the creation of adapted tools guaranteeing the quality and the confidentiality of the information while respecting the legal and ethical constraints, specific to this field. Visual Cryptography is the study of mathematical techniques related aspects of Information Security which allows Visual information to be encrypted in such a way that their decryption can be performed by the human visual system, without any complex cryptographic algorithms. This technique represents the secret image by several different shares of binary images. It is hard to perceive any clues about a secret image from individual shares. The secret message is revealed when parts or all of these shares are aligned and stacked together. In this paper we provide an overview of the emerging Visual Cryptography (VC) techniques used in the secure transfer of the medical images over in the internet. The related work is based on the recovering of secret image using a binary logo which is used to represent the ownership of the host image which generates shadows by visual cryptography algorithms. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 -6375(Online) Volume 1 Number 2, Sep -Oct (2010), pp. 133-146 © IAEME, http://www.iaeme.com/ijcet.html , © IAEME 134 An error correction-coding scheme is also used to create the appropriate shadow. The logo extracted from the half-toned host image identifies the cheating types. Furthermore, the logo recovers the reconstructed image when shadow is being cheated using an image self-verification scheme based on the Rehash technique which rehash the halftone logo for effective self verification of the reconstructed secret image without the need for the trusted third party (TTP). IJCET © I A E M E International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 -6367(Print), ISSN 0976 -6375(Online) Volume 1, Number 2

A Data Hiding Method Based on Partition Variable Block Size with Exclusive-or Operation on Binary Image

In this paper, we propose a high capacity data hiding method applying in binary images. Since a binary image has only two colors, black or white, it is hard to hide data imperceptible. The capacities and imperception are always in a trade-off problem. Before embedding we shuffle the secret data by a pseudo-random number generator to keep more secure. We divide the host image into several non-overlapping (2n+1) by (2n+1) sub-blocks in an M by N host image as many as possible, where n can equal 1, 2, 3 , …, or min(M,N). Then we partition each sub-block into four overlapping (n+1) by (n+1) sub-blocks. We skip the all blacks or all whites in each (2n+1) by (2n+1) sub-blocks. We consider all four (n+1) by (n+1) sub-blocks to check the XOR between the non overlapping parts and center pixel of the (2n+1) by (2n+1) sub-block, it embed n 2 bits in each (n+1) by (n+1) sub-block, totally are 4*n 2 . The entire host image can be embedded 4×n 2×M/(2n+1)×N/(2n+1) bits. The extraction way is simply to test the XOR between center pixel with their non-overlapping part of each sub-block. All embedding bits are collected and shuffled back to the original order. The adaptive means the partitioning sub-block may affect the capacities and imperception that we want to select. The experimental results show that the method provides the large embedding capacity and keeps imperceptible and reveal the host image lossless

Effect of lead oxide on concrete density for radiation shielding purposes

Selection of suitable shielding materials depends on the type, intensity and energy of radiation source, as well as the shielding properties such as mechanical strength, economic preparation and resistance to radiation damage. When compared to ordinary concrete, the addition of some materials with various fractions in the composition of concrete has provided concrete forms more efficient for gamma ray shielding. Concrete has proven to be an tremendous and adaptable shielding material with a well-established linear attenuation coefficient for gamma rays and neutrons. The objectives of this study is to determine the exact composition of concrete constituents and its density. Concrete samples were prepared by mixing cement, water, aggregate and additive with different composition and densities. Density was increases by decreasing the aggregates percent and increasing the additives such as lead oxide. Sample will be compacting to forming a solid material through pelleting and sintering process. Finally, it will undergo for radiation attenuation test. It was found that, substitution of lead oxide by aggregate causes increasing in the specific density and compressive strength of the concrete