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A secure image steganography algorithm based on least significant bit and integer wavelet transform

Journal of Systems Engineering and Electronics 2018年第3期29卷 639-649页

作者： ELSHAZLY Emad ABDELWAHAB Safey abouzaid refa.t ZAHRAN Osama ELARABY Sayed ELKORDY Mohamed Engineering Department Nuclear Research CenterAtomic Energy AuthorityCairo 11787Egypt Electronics and Electrical Communications Engineering Department Faculty of Electronic EngineeringMenoufia UniversityMenouf 32952Egypt

the rapid development of data communication in modern era demands secure exchange of information. Steganography is an established method for hiding secret data from an unauthorized access into a cover object in such a way that it is invisible to human eyes. the cover object can be image, text, audio,or video. this paper proposes a secure steganography algorithm that hides a bitstream of the secret text into the least significant bits（LSBs） of the approximation coefficients of the integer wavelet transform（IWt） of grayscale images as well as each component of color images to form stego-images. the embedding and extracting phases of the proposed steganography algorithms are performed using the MAtLAB software. Invisibility, payload capacity, and security in terms of peak signal to noise ratio（PSNR） and robustness are the key challenges to steganography. the statistical distortion between the cover images and the stego-images is measured by using the mean square error（MSE） and the PSNR, while the degree of closeness between them is evaluated using the normalized cross correlation（NCC）. the experimental results show that, the proposed algorithms can hide the secret text with a large payload capacity with a high level of security and a higher invisibility. Furthermore, the proposed technique is computationally efficient and better results for both PSNR and NCC are achieved compared with the previous algorithms.

关键词： image steganography image processing integer wavelet transform

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Petrophysical Analysis and Flow Units Characterization for Abu Madi Pay Zones in the Nile Delta Reservoirs

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Open Journal of Geology 2018年第12期8卷 1146-1165页

作者： Abdulaziz M. Abdulaziz Mohamed A. abouzaid A. S. Dahab Faculty of Engineering Cairo University Giza Egypt

Field development typically requires detailed petrophysical analysis and well defined hydraulic flow units for comprehensive formation evaluation and reservoir characterization. In the present study, pay zones petrophysics are studied using an assembly of well log data from 8 wells together with core plugs measurements. Petrophysical analysis showed a good reservoir quality with average water saturation increasing toward the East and Southeast of the study area. Using a multi-linear regression technique on well logs and core data, permeability is estimated at well locations for flow unit characterization and flow capacity calculation. Results showed that five hydraulic flow units are identified through the studied wells, with relatively good correlation. Such correlation indicated a good continuity in the net pay zone of Abu Madi Formation in the Nile Delta reservoirs. the developed hydraulic flow units (HFUs) are classified according to its hydraulic conductivity into two main categories: the first category comprises the units with low permeability (K 1270 mD). the reservoir flow capacity (RFC) of these units indicated the development of 4 distinct classes (~11, ~30, ~80, and greater than 130 ***). the wells within the Northwestern part of the study area showed three HFUs that relatively vary from those located at the Southeast where two HFUs are only developed. In addition, the Southeastern part of the reservoir is characterized by good RFC as indicated by the development of high order HFUs (3, 4, and 5) compared to the Northeastern part with predominated low order HFUs (1, 2, and 3). Such results are crucial for the efficient field development and profound reservoir management of oil and gas fields in the Nile Delta.

关键词： Abu Madi Formation Evaluation Hydraulic Flow Units Reservoir Characterization Flow Capacity

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