Hidden Capacity Research Articles

A Modified Image Steganography Method based on LSB Technique

Data hiding techniques are considered very important roles with the rapid growth of intensive transfer of multimedia contents and secret communications. On the other hand, steganography is one of the most important information hiding techniques. By using steganography, information is hidden in carriers such as images, audio files, text files, and video files. In this paper, a modified steganography method based on the spatial domain is proposed. Our proposed method represents the message by six binary bits by using LSBraille method (Braille method of reading and writing for blind people) instead of using the ASCII encoding format. In this method, three bits of the message are hidden in a single pixel, and a true image is composed of three layers (Red, Green, and Blue) layer. Two bits are embedded in the Blue layer, and one bit is embedded in the green layer of the same pixel. In the Blue layer, the message is not only embedded in the least significant bit (LSB), but also the second and the third LSB may be changed. However, during each process of embedding, only one bit of the Blue layer is changed. From the experimental results, it is found that the proposed method achieves a very high Maximum Hiding Capacity (MHC), and higher visual quality as indicated by the Peak Signal-toNoise Ratio (PSNR). General Terms Image Steganography, Data hiding in image.

An Image Steganography Algorithm for Hiding Data Based on HDWT, LZW and OPAP

Image steganography is the art of information hiding, which embeds a secret data into a cover image. However, high capacity of secret data and high quality of stego image are key issues in image steganography. In this paper, an image steganography technique based on Haar Discrete Wavelet Transform (HDWT), Lempel Ziv Welch (LZW) algorithm and Optimal Pixel Adjustment Process (OPAP) is proposed. The HDWT is used to increase the robustness of stego image against attacks. To increase the hidden capacity, LZW algorithm is performed on the secret message. The OPAP is then applied to reduce the embedding error between the cover image and stego image. The experimental results are evaluated by four standard images as covers, and with two types of secret messages. The results demonstrate high visual quality of stego image with large Hidden Capacity (HC) of secret data compared with recent techniques

An Image Steganography Algorithm for Hiding Data Based on HDWT, LZW and OPAP

Image steganography is the art of information hiding, which embeds a secret data into a cover image. However, high capacity of secret data and high quality of stego image are key issues in image steganography. In this paper, an image steganography technique based on Haar Discrete Wavelet Transform (HDWT), Lempel Ziv Welch (LZW) algorithm and Optimal Pixel Adjustment Process (OPAP) is proposed. The HDWT is used to increase the robustness of stego image against attacks. To increase the hidden capacity, LZW algorithm is performed on the secret message. The OPAP is then applied to reduce the embedding error between the cover image and stego image. The experimental results are evaluated by four standard images as covers, and with two types of secret messages. The results demonstrate high visual quality of stego image with large Hidden Capacity (HC) of secret data compared with recent techniques

Based on Binary Image Information Hiding Overview

Binary image storage is simple, compact structure makes the entropy of the unique advantages of the binary image data fax, text, bar code identification and digital signature has been widely used, it is precisely because of this feature makes color, grayscale image information hiding technique can not directly applied to the binary image information hiding. Summary outlines some recent findings binary image, and hidden capacity and robustness of these findings and other issues made ​​a brief comparison and discussion.

Binary Image Information Hiding Based on Research Gui Review

Binary image storage is simple, compact structure makes the entropy of the unique advantages of the binary image data fax, text, barcode recognition and digital signatures have been widely used, it is precisely because of this feature makes color, grayscale image information hiding technology can not be directly applied to the binary image information hiding. Summary provides an overview of some recent study based on the results of the binary image, and hidden capacity and robustness study based on the results of these and other issues made a brief comparison and discussion.

Efficient planning for LNG berths used by modern generation vessels

Efficient planning for LNG berths used by modern generation vessels needs a high level and accumulation of experiences. The planning process should cover the main components for the handling berth as berthing dolphins, mooring dolphins, berthing platform and suitable type of fenders. The planning and design should cover studying all the design forces that affect these items, including the hidden capacities. This efficient planning should cover two international standards. The first is the British standard (BS) and the second one is the (OCIMF, Oil Companies International Marine Forum) international standards for the petroleum companies forum. Applying the specifications for these two standards together, the efficient planning for LNG berths can be obtained. This research deals with that planning details in a simplified procedure, which is easy to follow.

Enhancing SMM Image Steganography Method by using LSBraille Image Steganography Method (SMMWB; Secret Message Matching With Braille)

ormation hiding techniques play a vital role in the recent years. Steganography is one of the important information hiding techniques which hides the existence of the message in the cover file. It gained importance in the past few years due to the increasing need for providing secrecy in an open environment like the internet. It can be defined as the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the internet. Steganography is used to conceal the information so that no one can sense its existence. It has many technical challenges such as high hiding capacity and imperceptibility. The current technique proposed in this paper is based on previously proposed SMM image steganography method (Image Steganography By Matching Secret Message With Pixels of Cover Image or, Secret Message Matching) combined with previously proposed LSBraille image steganography method (Image Steganography Method By Using Braille Method of Blind People). The proposed method provides more MHC (Maximum Hiding Capacity) than the previously proposed method SMM combined with an excellent PSNR (Peak Signal to Noise Ratio).

The ebbs and flows of changing acute bed capacity delays

This case study provides a summary of changes in acute hospital bed delays that have occurred over a 4-year period as identified through a Capacity Audit process. Royal Adelaide Hospital (RAH) designed a Capacity Audit process and tool that provides a systematic method to evaluate factors limiting access to inpatient bed capacity. The aim of the audit is to improve understanding of bed capacity by identifying key causes of delay for hospital inpatients and quantify the most frequent causes of blocked bed capacity. This can then be used to underpin targeted improvement work. The Capacity Audit has been undertaken at the RAH over three cycles. The Capacity Audit involves a survey of every open and staffed bed, identifying how the bed is being used: for acute care or treatment, if there was a delay to the patient for discharge, or if the bed was unavailable. The first and second cycle of the audit (2007-2008) involved a twice-daily survey over a 2-week period and the third audit cycle in 2010 occurred once daily for 1 week. On average, 620 beds were surveyed daily with an audit compliance rate ranging from 85-97%. This process has revealed almost 75% of beds are used positively for care. Of the remaining 25% of hidden capacity identified, non-clinical discharge delays account for 10% of total beds surveyed. Waiting for post-acute beds has consistently remained the main cause of acute bed delay. The Capacity Audit process and tool has been used to track progress, trends and change resulting from service improvement efforts, and to provide the evidence to commence strategies to reduce the hidden capacity issues. This case study has shown that whilst overall bed stock usage for positive care has not changed significantly there are various ebbs and flows over time in relation to the reasons for bed delays.

Choice of hiding capacity and frequency coefficients in DCT domain hiding algorithm

Hiding capacity,robustness and invisibility are some of the key parameters in information hiding system.Moreover,these parameters are seriously impacted by the difference of Discrete Cosine Transform(DCT) coefficients in DCT domain hiding algorithm.Embedded capacity,which is impacted by the mutual interference of visual perception of different DCT coefficients and the reverse DCT,was analyzed in this paper.Furthermore,the relation between hiding capacity and coefficients-chosen was given out in DCT domain hiding algorithm.A conclusion that there is no correlation between embedded position and robustness against compression of embedded information was put forward,and embedded capacity could be improved in reference to this conclusion.The experimental results show that this conclusion is correct even if the system is disturbed by noise.

Concealing information in image mosaics based on tile image features

This article presents a steganographic scheme that conceals secret information in image mosaics based on tile image features. An image mosaic, which is composed of many tiles, resembles a source image that is divided into small grids of identical size. The feature values of each grid and tile image are extracted by a wavelet transform. The similarity between a grid and a candidate tile is taken into account and secret data is inserted into a tile image according to its feature value. There is no modification of tile images and the stego-mosaic as a whole resembles its source image. The hidden data can be extracted by finding the feature values of all tile images of the mosaic. The stego-mosaic looks like its source image to avoid any suspicion; the hidden data are secure since no codebook is required to extract the concealed data and they are not easy to extract without knowing the algorithm. In addition, the concealment capacity is easy to expand by taking more bits of the coefficient of each tile. The experimental results have demonstrated that the embedded image mosaics created from the proposed method have good image qualities and large hidden capacity.

Reversible Watermarking Using Adaptive Edge-Guided Interpolation

Reversible watermarking is an open problem in information hiding field, with embedding the encoded bit '1' or '0' into some sensitive images, such as the law enforcement, medical records and military images. The technique can retrieve the original image without distortion, after the embedded message has been extracted. Histogram-based scheme is a remarkable breakthrough in reversible watermarking schemes, in terms of high embedding capacity and low distortion. This scheme is lack of capacity control due to the requirement for embedding large-scale data, because the largest hidden capacity is decided by the amount of pixels with the peak point. In this paper, we propose a reversible watermarking scheme to enlarge the number of pixels with the peak point as large as possible. This algorithm is based on an adaptive edge-guided interpolation, furthermore, hides messages by interpolation-error, i.e. the difference between the original and interpolated image value. Simulation results compared with other state-of-the-art reversible watermarking schemes in this paper demonstrate the validity of the proposed algorithm.

Mixing Codebooks of LBG, KPE and KFCG Algorithms to Increase Capacity of Information Hiding

Many researchers have studied reversible data hiding techniques in recent years and most have proposed reversible data hiding schemes that guarantees only that the original cover image can be reconstructed completely. Once the secret data are embedded in the compression domain and the receiver wants to store the cover image in a compression mode to save storage space, the receiver must extract the secret data, reconstruct the cover image, and compress the cover image again to generate compression codes. In this paper, we propose a novel data hiding method based on VQ compressed images. Codebooks of secret message & cover images are combined using shuffle algorithm. Experimental results indicate that our proposed scheme provides 100% hiding capacity or more that means secret message can be of same or more size than cover image and better image quality compared with existing schemes based on VQ compressed images. The technique is robust against stegaanalysis technique.

A High-Capacity Steganography Scheme for JPEG2000 Baseline System

Hiding capacity is very important for efficient covert communications. For JPEG2000 compressed images, it is necessary to enlarge the hiding capacity because the available redundancy is very limited. In addition, the bitstream truncation makes it difficult to hide information. In this paper, a high-capacity steganography scheme is proposed for the JPEG2000 baseline system, which uses bit-plane encoding procedure twice to solve the problem due to bitstream truncation. Moreover, embedding points and their intensity are determined in a well defined quantitative manner via redundancy evaluation to increase hiding capacity. The redundancy is measured by bit, which is different from conventional methods which adjust the embedding intensity by multiplying a visual masking factor. High volumetric data is embedded into bit-planes as low as possible to keep message integrality, but at the cost of an extra bit-plane encoding procedure and slightly changed compression ratio. The proposed method can be easily integrated into the JPEG2000 image coder, and the produced stego-bitstream can be decoded normally. Simulation shows that the proposed method is feasible, effective, and secure.

Identifying hidden capacity through modernization of genitourinary medicine services

Rates of sexually transmitted infections have continued to rise in recent years throughout the UK. Poor access to genitourinary medicine clinics has been highlighted as a major factor contributing to this increase. Despite a lack of investment in sexual health services, capacity for new patients has almost doubled over the past decade. However, a significant amount of unreleased capacity is still available within the service. This 'Six Sigma' study group was formed in 2003 to explore whether capacity could be enhanced by further reducing the ratio of follow-up to new-case patient visits. Following implementation of recommended changes, the mean follow-up to new-case ratio reduced from 0.82 (range 0.29-1.69) to 0.62 (range: 0.19-1.40). Crucially, this increase in capacity was achieved without adversely affecting quality of care. The Six Sigma group have developed the tools to release capacity in a controlled and validated way and are keen to help other clinics achieve similar results.