scholarly journals Reversible Steganographic Scheme for AMBTC-Compressed Image Based on (7,4) Hamming Code

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1236 ◽  
Author(s):  
Juan ◽  
Chia-Chen ◽  
Chin-Chen
Keyword(s):  
Data Extraction ◽  
Prediction Method ◽  
Recovery Phase ◽  
Type I ◽  
Hamming Code ◽  
Compression Method ◽  
Hiding Capacity ◽  
Compressed Images ◽  
Acceptable Image Quality

In recent years, compression steganography technology has attracted the attention of many scholars. Among all image compression method, absolute moment block truncation coding (AMBTC) is a simple and effective compression method. Most AMBTC-based reversible data hiding (RDH) schemes do not guarantee that the stego AMBTC compression codes can be translated by the conventional AMBTC decoder. In other words, they do not belong to Type I AMBTC-based RDH scheme and easily attract malicious users’ attention. To solve this problem and enhance the hiding capacity, we used (7,4) hamming code to design a Type I AMBTC-based RDH scheme in this paper. To provide the reversibility feature, we designed a prediction method and judgement mechanism to successfully select the embeddable blocks during the data embedding phase and data extraction and recovery phase. In comparing our approach with other BTC-based schemes, it is confirmed that our hiding capacity is increased while maintaining the limited size of the compression codes and acceptable image quality of the stego AMBTC-compressed images.

scholarly journals Reversible Data Hiding in Encrypted Image Based on (7, 4) Hamming Code and UnitSmooth Detection

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 790
Author(s):  
Lin Li ◽  
Chin-Chen Chang ◽  
Chia-Chen Lin
Keyword(s):  
Data Hiding ◽  
Privacy Protection ◽  
Reversible Data Hiding ◽  
Signal To Noise Ratio ◽  
Data Extraction ◽  
Hamming Code ◽  
Hiding Capacity ◽  
Encrypted Images

With the development of cloud storage and privacy protection, reversible data hiding in encrypted images (RDHEI) plays the dual role of privacy protection and secret information transmission. RDHEI has a good application prospect and practical value. The current RDHEI algorithms still have room for improvement in terms of hiding capacity, security and separability. Based on (7, 4) Hamming Code and our proposed prediction/ detection functions, this paper proposes a Hamming Code and UnitSmooth detection based RDHEI scheme, called HUD-RDHEI scheme for short. To prove our performance, two database sets—BOWS-2 and BOSSBase—have been used in the experiments, and peak signal to noise ratio (PSNR) and pure embedding rate (ER) are served as criteria to evaluate the performance on image quality and hiding capacity. Experimental results confirm that the average pure ER with our proposed scheme is up to 2.556 bpp and 2.530 bpp under BOSSBase and BOWS-2, respectively. At the same time, security and separability is guaranteed. Moreover, there are no incorrect extracted bits during data extraction phase and the visual quality of directly decrypted image is exactly the same as the cover image.

A NONUNIFORM HIGH-QUALITY IMAGE COMPRESSION METHOD TO PRESERVE USER-SPECIFIED COMPRESSION RATIO

2011 ◽  
Vol 11 (03) ◽  
pp. 355-375 ◽  
Author(s):  
MOHAMMAD REZA BONYADI ◽  
MOHSEN EBRAHIMI MOGHADDAM
Keyword(s):  
Image Compression ◽  
Compression Ratio ◽  
Signal To Noise Ratio ◽  
Linear Mapping ◽  
Compression Method ◽  
High Quality ◽  
Compressed Images ◽  
High Quality Image ◽  
Quality Image

Most of image compression methods are based on frequency domain transforms that are followed by a quantization and rounding approach to discard some coefficients. It is obvious that the quality of compressed images highly depends on the manner of discarding these coefficients. However, finding a good balance between image quality and compression ratio is an important issue in such manners. In this paper, a new lossy compression method called linear mapping image compression (LMIC) is proposed to compress images with high quality while the user-specified compression ratio is satisfied. This method is based on discrete cosine transform (DCT) and an adaptive zonal mask. The proposed method divides image to equal size blocks and the structure of zonal mask for each block is determined independently by considering its gray-level distance (GLD). The experimental results showed that the presented method had higher pick signal to noise ratio (PSNR) in comparison with some related works in a specified compression ratio. In addition, the results were comparable with JPEG2000.

scholarly journals Reversible Data Hiding for AMBTC Compressed Images Based on Matrix and Hamming Coding

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 281
Author(s):  
Chia-Chen Lin ◽  
Juan Lin ◽  
Chin-Chen Chang
Keyword(s):  
Data Hiding ◽  
Mean Value ◽  
Hamming Code ◽  
File Size ◽  
Hiding Capacity ◽  
Compressed Images ◽  
Matrix Embedding ◽  
Previous State ◽  
Disjoint Sets ◽  
The Mean

In this paper, we propose a two-layer data hiding method by using the Hamming code to enhance the hiding capacity without causing significantly increasing computation complexity for AMBTC-compressed images. To achieve our objective, for the first layer, four disjoint sets using different combinations of the mean value (AVG) and the standard deviation (VAR) are derived according to the combination of secret bits and the corresponding bitmap, following Lin et al.’s method. For the second layer, these four disjoint sets are extended to eight by adding or subtracting 1, according to a matrix embedding with (7, 4) Hamming code. To maintain reversibility, we must return the irreversible block to its previous state, which is the state after the first layer of data is embedded. Then, to losslessly recover the AMBTC-compressed images after extracting the secret bits, we use continuity feature, the parity of pixels value, and the unique number of changed pixels in the same row to restore AVG and VAR. Finally, in comparison with state-of-the-art AMBTC-based schemes, it is confirmed that our proposed method provided two times the hiding capacity comparing with other six representative AMBTC-based schemes while maintaining acceptable file size of steog-images.

Health-related quality of life one year after surgical treatment of the type I chronic aortic dissection

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Oksana Kamenskaya ◽  
Asya Klinkova ◽  
Irina Loginova ◽  
Alexander Chernyavskiy ◽  
Dmitry Sirota ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Surgical Treatment ◽  
Aortic Dissection ◽  
Type I ◽  
Health Related Quality ◽  
Chronic Aortic Dissection ◽  
Related Quality ◽  
Health Related ◽  
One Year

The concept of motivation for effective credit risk management

2020 ◽  
Vol 26 (11) ◽  
pp. 2567-2593
Author(s):  
M.V. Pomazanov
Keyword(s):  
Risk Management ◽  
Economic Modeling ◽  
Type I ◽  
Credit Risk Management ◽  
Curve Modeling ◽  
Business Functions ◽  
The Common ◽  
Lending Decisions ◽  
The One

Subject. The study addresses the improvement of risk management efficiency and the quality of lending decisions made by banks. Objectives. The aim is to present the bank management with a fair algorithm for risk management motivation on the one hand, and the credit management (business) on the other hand. Within the framework of the common goal to maximize risk-adjusted income from loans, this algorithm will provide guidelines for ‘risk management’ and ‘business’ functions on how to improve individual and overall efficiency. Methods. The study employs the discriminant analysis, type I and II errors, Lorentz curve modeling, statistical analysis, economic modeling. Results. The paper offers a mechanism for assessing the quality of risk management decisions as opposed to (or in support of) decisions of the lending business when approving transactions. The mechanism rests on the approach of stating type I and II errors and the corresponding classical metric of the Gini coefficient. On the ‘business’ side, the mechanism monitors the improvement or deterioration of the indicator of changes in losses in comparison with the market average. Conclusions. The study substantiates the stimulating ‘rules of the game’ between the ‘business’ and ‘risk management’ to improve the efficiency of the entire business, to optimize interactions within the framework of internal competition. It presents mathematical tools to calculate corresponding indicators of the efficiency of internally competing entities.

Effectiveness of the Chiari Health Index for Pediatrics instrument in measuring postoperative health-related quality of life in pediatric patients with Chiari malformation type I

2020 ◽  
pp. 1-6
Author(s):  
Georgina E. Sellyn ◽  
Alan R. Tang ◽  
Shilin Zhao ◽  
Madeleine Sherburn ◽  
Rachel Pellegrino ◽  
...  
Keyword(s):  
Surgical Intervention ◽  
Type I ◽  
Health Related Quality ◽  
Health Index ◽  
Chiari Malformation Type I ◽  
Related Quality ◽  
Health Related ◽  
Over Time

OBJECTIVEThe authors’ previously published work validated the Chiari Health Index for Pediatrics (CHIP), a new instrument for measuring health-related quality of life (HRQOL) for pediatric Chiari malformation type I (CM-I) patients. In this study, the authors further evaluated the CHIP to assess HRQOL changes over time and correlate changes in HRQOL to changes in symptomatology and radiological factors in CM-I patients who undergo surgical intervention. Strong HRQOL evaluation instruments are currently lacking for pediatric CM-I patients, creating the need for a standardized HRQOL instrument for this patient population. This study serves as the first analysis of the CHIP instrument’s effectiveness in measuring short-term HRQOL changes in pediatric CM-I patients and can be a useful tool in future CM-I HRQOL studies.METHODSThe authors evaluated prospectively collected CHIP scores and clinical factors of surgical intervention in patients younger than 18 years. To be included, patients completed a baseline CHIP captured during the preoperative visit, and at least 1 follow-up CHIP administered postoperatively. CHIP has 2 domains (physical and psychosocial) comprising 4 components, the 3 physical components of pain frequency, pain severity, and nonpain symptoms, and a single psychosocial component. Each CHIP category is scored on a scale, with 0 indicating absent and 1 indicating present, with higher scores indicating better HRQOL. Wilcoxon paired tests, Spearman correlations, and linear regression models were used to evaluate and correlate HRQOL, symptomatology, and radiographic factors.RESULTSSixty-three patients made up the analysis cohort (92% Caucasian, 52% female, mean age 11.8 years, average follow-up time 15.4 months). Dural augmentation was performed in 92% of patients. Of the 63 patients, 48 reported preoperative symptoms and 42 had a preoperative syrinx. From baseline, overall CHIP scores significantly improved over time (from 0.71 to 0.78, p < 0.001). Significant improvement in CHIP scores was seen in patients presenting at baseline with neck/back pain (p = 0.015) and headaches (p < 0.001) and in patients with extremity numbness trending at p = 0.064. Patients with syringomyelia were found to have improvement in CHIP scores over time (0.75 to 0.82, p < 0.001), as well as significant improvement in all 4 components. Additionally, improved CHIP scores were found to be significantly associated with age in patients with cervical (p = 0.009) or thoracic (p = 0.011) syrinxes.CONCLUSIONSThe study data show that the CHIP is an effective instrument for measuring HRQOL over time. Additionally, the CHIP was found to be significantly correlated to changes in symptomatology, a finding indicating that this instrument is a clinically valuable tool for the management of CM-I.

scholarly journals 3D DCT Based Image Compression Method for the Medical Endoscopic Application

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1817
Author(s):  
Jiawen Xue ◽  
Li Yin ◽  
Zehua Lan ◽  
Mingzhu Long ◽  
Guolin Li ◽  
...  
Keyword(s):  
Image Compression ◽  
Compression Ratio ◽  
Signal To Noise Ratio ◽  
Blocking Artifacts ◽  
Compression Method ◽  
High Compression Ratio ◽  
Multiplication Operation ◽  
3D Data ◽  
Wireless Capsule

This paper proposes a novel 3D discrete cosine transform (DCT) based image compression method for medical endoscopic applications. Due to the high correlation among color components of wireless capsule endoscopy (WCE) images, the original 2D Bayer data pattern is reconstructed into a new 3D data pattern, and 3D DCT is adopted to compress the 3D data for high compression ratio and high quality. For the low computational complexity of 3D-DCT, an optimized 4-point DCT butterfly structure without multiplication operation is proposed. Due to the unique characteristics of the 3D data pattern, the quantization and zigzag scan are ameliorated. To further improve the visual quality of decompressed images, a frequency-domain filter is proposed to eliminate the blocking artifacts adaptively. Experiments show that our method attains an average compression ratio (CR) of 22.94:1 with the peak signal to noise ratio (PSNR) of 40.73 dB, which outperforms state-of-the-art methods.

The contribution of French patient and consumer groups to health technology assessments over a 2-year period: an observational retrospective study

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Cedric Gesbert ◽  
Joëlle André-Vert ◽  
Marc Guerrier ◽  
Margaret Galbraith ◽  
Christine Devaud ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Human Resources ◽  
Data Extraction ◽  
Health Technology ◽  
Family Impact ◽  
National Authority ◽  
Public Authorities ◽  
Pricing Decision ◽  
Open Question

Abstract Background In 2017, The French National Authority for Health (HAS) created an open, online, systematic contribution process to enable patient and consumer groups (PCGs) to contribute to health technology assessment (HTA) carried out to aid public authorities in reimbursement and pricing decision making. Objectives This retrospective study analyzes how French PCGs contributed to the HTA process within the HAS for the first 2 years of this new mechanism. Methods PCG contributions received between 01 January 2017 and 31 December 2018 and the recording of deliberations leading to reports of the corresponding HTAs were included. Analysis grids were designed by the investigators with 5 rounds of refinement tests on 10 random PCG contributions and the reports. Systematic data extraction was then performed separately by two investigators. PCG answers to the open-question templates and the related final HTA report published by the HAS were analyzed. Results Seventy-nine contributions from 44 PCGs were received and analyzed by the HAS for 78 out of the 592 HTAs performed for drugs or medical devices during the 2-year period. Twenty-five percent of the HTAs performed for drugs received at least one contribution. The contributions covered quality-of-life aspects, access to care, and personal and family impact. Membership and budget of the contributing PCGs varied greatly. Conclusions The experience gained in the first 2 years demonstrates the feasibility of the process and the fact that PCG contribution actually provides relevant input on the patient perspective for HTAs used for reimbursement decisions. The challenges identified on the side of PCGs were time constraints and human resources.

scholarly journals Effectiveness of Antalgic Therapies in Patients with Vertebral Bone Metastasis: A Protocol for a Systematic Review and Meta-Analysis

2021 ◽  
Vol 18 (8) ◽  
pp. 3991
Author(s):  
Antonio Jose Martin-Perez ◽  
María Fernández-González ◽  
Paula Postigo-Martin ◽  
Marc Sampedro Pilegaard ◽  
Carolina Fernández-Lao ◽  
...  
Keyword(s):  
Systematic Review ◽  
Bone Metastasis ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Cochrane Library ◽  
Pharmacological Intervention ◽  
Vertebral Metastasis ◽  
Randomized Controlled Clinical Trials

There is no systematic review that has identified existing studies evaluating the pharmacological and non-pharmacological intervention for pain management in patients with bone metastasis. To fill this gap in the literature, this systematic review with meta-analysis aims to evaluate the effectiveness of different antalgic therapies (pharmacological and non-pharmacological) in the improvement of pain of these patients. To this end, this protocol has been written according to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) and registered in PROSPERO (CRD42020135762). A systematic search will be carried out in four international databases: Medline (Via PubMed), Web of Science, Cochrane Library and SCOPUS, to select the randomized controlled clinical trials. The Risk of Bias Tool developed by Cochrane will be used to assess the risk of bias and the quality of the identified studies. A narrative synthesis will be used to describe and compare the studies, and after the data extraction, random effects model and a subgroup analyses will be performed according to the type of intervention, if possible. This protocol aims to generate a systematic review that compiles and synthesizes the best and most recent evidence on the treatment of pain derived from vertebral metastasis.

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