Topological Data Analysis for Image Tampering Detection

This paper introduces a topological approach to detection of image tampering for forensics purposes. This is based on the emerging Topological Data Analysis (TDA) concept of persistent homological invariants associated with certain image features. Image features of interest are pixels that have a uniform Local Binary pattern (LBP) code representing texture feature descriptors. We construct the sequence of simplicial complexes for increasing sequence of distance thresholds whose vertices are the selected set of pixels, and calculate the corresponding non-increasing sequence of homology invariants (number of connected components). The persistent homology of this construction describes the speed with which the sequence terminates, and our tamper detection scheme exploit its sensitivity to image tampering/degradation. We test the performance of this approach on a sufficiently large image dataset from a benchmark dataset of passport photos, and show that the persistent homology sequence defines a discriminating criterion for the morphing attacks (i.e. distinguishing morphed images from genuine ones)

Topological Image Texture Analysis for Quality Assessment

Image quality is a major factor influencing pattern recognition accuracy and help detect image tampering for forensics. We are concerned with investigating topological image texture analysis techniques to assess different type of degradation. We use Local Binary Pattern (LBP) as a texture feature descriptor. For any image construct simplicial complexes for selected groups of uniform LBP bins and calculate persistent homology invariants (e.g. number of connected components). We investigated image quality discriminating characteristics of these simplicial complexes by computing these models for a large dataset of face images that are affected by the presence of shadows as a result of variation in illumination conditions. Our tests demonstrate that for specific uniform LBP patterns, the number of connected component not only distinguish between different levels of shadow effects but also help detect the infected regions as well

Double-Staged Syndrome Coding Scheme for Improving Information Transmission Security over the Wiretap Channel

This paper presents a study of a syndrome coding scheme for different binary linear error correcting codes that refer to the code families such as BCH, BKLC, Golay, and Hamming. The study is implemented on Wyner’s wiretap channel model when the main channel is error-free and the eavesdropper channel is a binary symmetric channel with crossover error probability (0 < Pe ≤ 0.5) to show the security performance of error correcting codes while used in the single-staged syndrome coding scheme in terms of equivocation rate. Generally, these codes are not designed for secure information transmission, and they have low equivocation rates when they are used in the syndrome coding scheme. Therefore, to improve the transmission security when using these codes, a modified encoder which consists of a double-staged syndrome coding scheme, is proposed. Two models are implemented in this paper: the first model utilizes one encoding stage of the conventional syndrome coding scheme. In contrast, the second model utilizes two encoding stages of the syndrome coding scheme to improve the results obtained from the first model. The C++ programming language, in conjunction with the NTL library, is used for obtaining simulation results for the implemented models. The equivocation rate results from the second model were compared to both the results of the first model and of the unsecured transmission (transmission of data without encryption). The comparison revealed that the security performance of the second model is better than the first model and the insecure system, as the equivocation for all the simulated codes over the proposed model reaches at least %97 at the Pe = 0.1.

Topological data analysis to improve exemplar-based inpainting

Image inpainting is the process of filling in the missing region to preserve continuity of its overall content and semantic. In this paper, we present a novel approach to improve an existing scheme, called exemplar-based inpainting algorithm, using Topological Data Analysis (TDA). TDA is a mathematical approach concern studying shapes or objects to gain information about connectivity and closeness property of those objects. The challenge in using exemplar-based inpainting is that missing regions neighborhood area needs to have a relatively simple texture and structure. We studied the topological properties (e.g. number of connected components) of missing regions surrounding the missing area by building a sequence of simplicial complexes (known as persistent homology) based on a selected group of uniform Local binary Pattern LBP. Connected components of image regions generated by certain landmark pixels, at different thresholds, automatically quantify the texture nature of the missing regions surrounding areas. Such quantification help determine the appropriate size of patch propagation. We have modified the patch propagation priority function using geometrical properties of curvature of isophote and improved the matching criteria of patches by calculating the correlation coefficients from spatial, gradient and Laplacian domain. We use several image quality measures to illustrate the performance of our approach in comparison to similar inpainting algorithms. In particular, we shall illustrate that our proposed scheme outperforms the state-of-the-art exemplar-based inpainting algorithm

Polyvascular Disease in Patients Presenting with Acute Coronary Syndrome: Its Predictors and Outcomes

We evaluated prevalence and clinical outcome of polyvascular disease (PolyVD) in patients presenting with acute coronary syndrome (ACS). Data for 7689 consecutive ACS patients were collected from the 2nd Gulf Registry of Acute Coronary Events between October 2008 and June 2009. Patients were divided into 2 groups (ACS with versus without PolyVD). All-cause mortality was assessed at 1 and 12 months. Patients with PolyVD were older and more likely to have cardiovascular risk factors. On presentation, those patients were more likely to have atypical angina, high resting heart rate, high Killip class, and GRACE risk scoring. They were less likely to receive evidence-based therapies. Diabetes mellitus, renal failure, and hypertension were independent predictors for presence of PolyVD. PolyVD was associated with worse in-hospital outcomes (except for major bleedings) and all-cause mortality even after adjusting for baseline covariates. Great efforts should be directed toward primary and secondary preventive measures

Demystifying Smoker's Paradox: A Propensity Score-Weighted Analysis in Patients Hospitalized With Acute Heart Failure.

Background Smoker's paradox has been observed with several vascular disorders, yet there are limited data in patients with acute heart failure (HF). We examined the effects of smoking in patients with acute HF using data from a large multicenter registry. The objective was to determine if the design and analytic approach could explain the smoker's paradox in acute HF mortality. Methods and Results The data were sourced from the acute HF registry (Gulf CARE [Gulf Acute Heart Failure Registry]), a multicenter registry that recruited patients over 10 months admitted with a diagnosis of acute HF from 47 hospitals in 7 Middle Eastern countries. The association between smoking and mortality (in hospital) was examined using covariate adjustment, making use of mortality risk factors. A parallel analysis was performed using covariate balancing through propensity scores. Of 5005 patients hospitalized with acute HF, 1103 (22%) were current smokers. The in-hospital mortality rates were significantly lower in current smoker's before (odds ratio, 0.71; 95% CI, 0.52-0.96) and more so after (odds ratio, 0.47; 95% CI, 0.31-0.70) covariate adjustment. With the propensity score-derived covariate balance, the smoking effect became much less certain (odds ratio, 0.63; 95% CI, 0.36-1.11). Conclusions The current study illustrates the fact that the smoker's paradox is likely to be a result of residual confounding as covariate adjustment may not resolve this if there are many competing prognostic confounders. In this situation, propensity score methods for covariate balancing seem preferable. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01467973.Gulf CARE (Gulf Acute Heart Failure Registry) is an investigator- initiated study conducted under the auspices of the Gulf Heart Association and funded by Servier, Paris, France; and (for centers in Saudi Arabia), by the Saudi Heart Association (The Deanship of Scientific Research at King Saud University, Riyadh, Saudi Arabia [research group number: RG -1436- 013]). This does not alter our adherence to policies on sharing data and materials; and the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The publication of this article was funded by the Qatar National Library

Clinical presentation and outcomes of peripartum cardiomyopathy in the Middle East: a cohort from seven Arab countries

Aims: Published data on the clinical presentation of peripartum cardiomyopathy (PPCM) are very limited particularly from the Middle East. The aim of this study was to examine the clinical presentation, management, and outcomes of patients with PPCM using data from a large multicentre heart failure (HF) registry from the Middle East. Methods and results: From February to November 2012, a total of 5005 consecutive patients with HF were enrolled from 47 hospitals in 7 Middle East countries. From this cohort, patients with PPCM were identified and included in this study. Clinical features, in-hospital, and 12 months outcomes were examined. During the study period, 64 patients with PPCM were enrolled with a mean age of 32.5 ± 5.8 years. Family history was identified in 11 patients (17.2%) and hypertension in 7 patients (10.9%). The predominant presenting symptom was dyspnoea New York Heart Association class IV in 51.6%, class III in 31.3%, and class II in 17.2%. Basal lung crepitations and peripheral oedema were the predominant signs on clinical examination (98.2% and 84.4%, respectively). Most patients received evidence-based HF therapies. Inotropic support and mechanical ventilation were required in 16% and 5% of patients, respectively. There was one in-hospital death (1.6%), and after 1 year of follow-up, nine patients were rehospitalized with HF (15%), and one patient died (1.6%). Conclusions: A high index of suspicion of PPCM is required to make the diagnosis especially in the presence of family history of HF or cardiomyopathy. Further studies are warranted on the genetic basis of PPCM.Gulf CARE is an investigator-initiated study conducted under the auspices of the Gulf Heart Association and funded by Servier, Paris, France, and (for centres in Saudi Arabia) by the Saudi Heart Association [The Deanship of Scientific Research at King Saud University, Riyadh, Saudi Arabia (Research Group Number RG-1436-013)]. This does not alter our adherence to policies on sharing data and materials, and the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Topological Data Analysis as Image Steganalysis Technique

Image Steganography is the technique of hiding sensitive data (secrete message) inside cover images in a way that no suspicion occurs to attackers, while steganalysis is the technique of detecting the embedded data by unauthorized persons. As a first step of detecting hidden data, distinguishing between original (Images without secrete message) and Stego (Images contain secrete message) is important. In this paper we design and propose a novel scheme based on the emerging field of Topological Data Analysis (TDA) concept of persistent homological (PH) invariants (e.g. No. of connected components), associated with certain image features. Selected group of Uniform Local Binary Pattern (LBP), which is a texture descriptor, codes representing the image features used to construct a sequence of simplicial complexes (SC) from an increasing sequence of distance thresholds (T). We calculate the corresponding non-increasing sequence of homological invariants which shows the speed at which the constructed sequence of SCs terminates. This approach is sensitive to differentiate original images from stego images. We test this approach on two different embedding techniques which are Traditional Least Significant Bits (TLSB) embedding technique, spatial Universal Wavelet Relative Distortion (S-UNIWARD) and LSB-Witness embedding technique together with a large number of images chosen randomly from large database of images. Preliminary results show that the PH sequence defines a discriminates criterion for steganalysis purpose with over 90% classification accuracy