Single Digital Image Research Articles

Multiple-Exposure PTV With Variable Time Steps

Recording multiple exposures of the tracer particles onto a single digital image has the potential to simplify the hardware needed for 3D PTV measurements. A sequence with equal time intervals leads to the well-known directional ambiguity problem. Instead, a sequence with irregular time-intervals (two or more) allows resolving the ambiguity. Two fundamental criteria are introduced that determine whether a set of particle samples corresponds to a physical trace for a given neighborhood: the kinematic similarity criterion imposes similarity (i.e. proportionality) between the length travelled by the particle and time elapsed. Additionally, the trace regularity criterion favors sets with minimum fluctuations of the velocity vector. A numerical algorithm, based on combinatorial analysis is presented, whereby all possible sets are scrutinized and the set of particles yielding the minimum disparity from the above criteria corresponds to the physical trace. The algorithm is demonstrated using 3D experimental data and results are benchmarked against the state-of-the-art time-resolved analysis Shakethe-Box (single-frame, single-exposure).

A Technique for In-Situ Displacement and Strain Measurement with Laboratory-Scale X-Ray Computed Tomography

Abstract Purpose: Establish a technique for simultaneous interrupted volumetric imaging of internal structure and time-resolved full-field surface strain measurements during in-situ X-ray micro-computed tomography (XCT) experiments. This enables in-situ testing of stiff materials with large forces relative to the compliance of the in-situ load frame, which might exhibit localization (e.g., necking, compaction banding) and other inhomogeneous behaviors.Methods: The system utilizes a combination of in-situ XCT, 2D X-ray imaging, and particle tracking to conduct volumetric imaging of the internal structure of a specimen with interrupted loading and surface strain mapping during loading. Critically, prior to the laboratory-scale XCT experiments, specimens are speckled with a high-X-ray-contrast powder that is bonded the surface. During in-situ loading, the XCT system is programmed to capture sequential 2D X-ray images orthogonal to the speckled specimen surface. A single particle tracking (SPT) or digital image correlation (DIC) algorithm is used to measure full-field surface strain evolution throughout the time-sequence of images. At specified crosshead displacements, the motion and 2D image sequence is paused for volumetric XCT image collection. Results: We show example results on a micro-tensile demonstration specimen additive manufactured from Inconel 718 nickel-chrome alloy. Results include XCT volume reconstructions, crosshead-based engineering stress, and full-field strain maps. Conclusion: We demonstrate an in-situ technique to obtain surface strain evolution during laboratory-scale XCT testing and interrupted volumetric imaging. This allows closer investigation of, for example, the effect of micro-pores on the strain localization behavior of additive manufactured metal alloys. In addition to describing the method using a representative test piece, the dataset and code are published as open-source resources for the community. Graphical abstract

Deep learning-based software and hardware framework for a noncontact inspection platform for aggregate grading

Due to the problem of complex aggregate stacking and adhesion, current construction site aggregate grade detection relies on traditional screening methods and single digital image processing technology, which causes inefficiency and segmentation identification difficulties. This problem has become a technical bottleneck in achieving automatic construction site mixed aggregate grade detection. This study constructs a noncontact testing platform for aggregate gradation based on a self-developed sampling and testing device for mixed aggregate gradation and improved deep learning algorithms, which enables rapid testing of mixed aggregate gradation. Based on the principle of instance segmentation, each aggregate in the stacked mixed aggregates collected based on hardware observation is used as an instance to detect independent aggregate targets in the mixed aggregate images with different moisture contents, sand contents and cohesive stacking. An improved aggregate segmentation convolutional neural network model (AS Mask RCNN: Aggregate Segmentation Mask RCNN) is used to achieve the gradation detection of mixed aggregates. This study employed three different types of experiments, and the results showed that the AS Mask RCNN network model achieved an accuracy of over 89.13% in the three experimental situations, and compared the results with those of the Faster RCNN and Mask R-CNN models, with an accuracy improvement of 8.85% and a reduction of 1.29 s in the processing time of a single image segmentation, which can meet the field near real-time detection requirements. The self-developed noncontact testing platform for aggregate grading can adapt to practical applications in complex environments, enabling digital, automated and intelligent noncontact rapid testing of mixed aggregate grading, further improving the accuracy of aggregate grading testing and serving the high-quality development of reservoir dam construction in China.

Evaluation of workability, microstructure and mechanical properties of recycled powder geopolymer reinforced by waste hydrophilic basalt fiber

The recycled powder geopolymer (RPG) is an environmental-friendly cementitious material prepared from recycled powder (RP) recovered from construction waste. The preparation of geopolymers has promoted the development of sustainable materials, but the great brittleness limits the application scenarios. In this paper, the waste hydrophilic basalt fiber (WHBF) was used to reinforce RPG and the mechanical properties, toughness and microstructure were evaluated. The results indicated that the addition of WHBF significantly improved the compressive, flexural and tensile strength of the RPG. Adding 0.6% WHBF with 6 mm in length and 13 μm in diameter improved the compressive strength, flexural strength and tensile strength by 59.43%, 85.20% and 121.74% in 28 days, respectively, compared to the control group. The single fiber pull-out test and Digital Image Correlation (DIC) analysis indicated that the interfacial properties of the WHBF with appropriate geometric parameters were high and the direction and rate of crack growth were significantly changed, which greatly improved the toughness of the matrix. The analysis of water absorption and Mercury Intrusion Porosimetry (MIP) showed that although the incorporation of WHBF increased the porosity of RPG, the pore size was small and had no adverse effect on the matrix. The microstructure analysis showed that the addition of WHBF benefited the formation of additional gel, which provided a better bonding and frictional stress transfer path for the composites. Meanwhile, the energy absorption capacity of the composites was significantly improved and the crack propagation was inhibited. Furthermore, the WHBF enhanced the long-term drying shrinkage performance of RPG. This work suggested that the recycled powder geopolymer reinforced by waste hydrophilic basalt fiber shows excellent potential for application.

Method of quantitative assessment of the shape of the lumbar-thoracic spine

Introduction. The presence of deformation of the lumbar-thoracic spine in the sagittal plane is the main factor determining the health status of adult patients. The studies of the features of human posture with or without spinal deformities in statics and movement have been in the focus of clinician attention for a long time. Recent studies offer a unifi ed approach to assessing the position of the vertebrae. However, no such studies have been conducted to analyze the lumbar-thoracic junction. The purpose of the work — to develop a method of qualitative and quantitative assessment of the vertebra positions in lumbar-thoracic junction. Issues: to develop a schematic model of the lumbar-thoracic spine; to develop a typology of the lumbar-thoracic transition; to develop an objective indicator refl ecting the features of the lumbar-thoracic transition in the patient; to characterize the age characteristics of this area of the spine.Materials and methods. A study of digital radiographs for all spine parts in sagittal projection for 141 patients with dorsopathies, 57 men and 84 women aged from 21 to 88 years, was conducted. The study was performed on a personal computer screen, without patient participation. A single digital X-ray image of the spine in the sagittal projection was obtained for each patient. The occipital vertical and anteroposterior axes of TIX–LV (LVI) vertebrae (r axes) were applied to the combined radiograph. At the intersection points of the axes with the occipital vertical, the perpendiculars to the r axes were restored, and the angles between the perpendiculars and the occipital vertical (angles r) were measured. Statistical analysis was carried out using the Microsoft Offi ce Excel 2007 software package.Results. Schematic models of the lumbar-thoracic junction for all cases were constructed on the basis of the data obtained. The models were used to compare the vertebra positions and describe three form types of lumbar-thoracic junction: normal, straightened and reinforced. An aggregated ArTL indicator is proposed and the boundaries of this indicator were determined for the quantitative assessment of each case. It is demonstrated that the age features for this part of the spine are expressed not in a monotonous change in the average value of ArTL with age, but in an increase in the proportion of patients with straightened and enhanced kyphosis, and it is especially noticeable in the group of people over 75 years old.Conclusion. The proposed technology for assessing the position of the vertebrae of the lumbar-thoracic spine was developed to satisfy the needs of osteopaths and specialists in restorative medicine, and this technology is presented for the fi rst time. In the course of the study, schematic models of the spine of each patient were developed; an ArTL indicator was proposed to quantify the type of the lumbar-thoracic region shape. The boundaries for the diagnosis of each type were determined and a study was conducted to identify the age trend. The study revealed the absence of a linear age trend of changes in this part of the spine. Among people over 75 years of age, patients with straightened or enhanced kyphosis of this zone were more common.

Research on the interface bonding performance between FRCM and masonry under salt erosion environment

Fabric reinforced cementitious matrix (FRCM) has a good application prospect in the field of masonry structure reinforcement. The interface bonding performance between FRCM and masonry is one of the important indicators to evaluate the reinforcement effect of FRCM. There are many studies on the interface bonding performance between FRCM and masonry under normal environment, but few on the interface bonding performance in salt erosion environment, which need to carry out further research. In this paper, based on the single shear test and digital image correlation technology (DIC), the influence of the interface bonding length on the interface bonding performance between FRCM and masonry in a conventional environment was studied and the effective bonding length was determined; the interface bonding performance between FRCM and masonry in the salt erosion environment was studied; the main research factors are the number of dry-wet cycles, the concentration of the salt solution and the types of matrix. Especially, in terms of matrix type, the effects of engineered cementitious composite (ECC) and mortar as FRCM matrix on interface bonding performance are considered. The results show that FRCM, ECC and mortar matrix do not hinder the transportation of salt and cause accumulation at the interface between composite materials and masonry; the slip failure of the textile in the matrix occurs mainly, and the fiber bundles in the matrix are corroded to a certain extent; the interface bonding performance of specimens in the salt corrosion environment using FRCM matrix will reduce, while the specimens using ECC and mortar matrix will improve.

Reliability of a simple fluoroscopic image to assess leg length discrepancy during direct anterior approach total hip arthroplasty.

BACKGROUNDDirect anterior approach (DAA) total hip arthroplasty (THA) in a supine position provides a unique opportunity to assess leg length discrepancy (LLD) intra-operatively with fluoroscopy. Reported fluoroscopic techniques are useful but are generally complicated or costly. Despite the use of multiple techniques for leg length assessment, LLD continues to be a major post-operative source of patient dissatisfaction further emphasizing the importance of near-anatomic restoration. The utility of an alternative direct measurement of LLD on an intra-operative fluoroscopic pelvic image during DAA THA has not been reported. AIMTo determine the reliability of a novel simple intra-operative measurement of LLD using a parallel line technique on a single fluoroscopic digital image of the pelvis.METHODSOne hundred and seventy-one patients who underwent DAA THA were included for analysis. Intra-operative fluoroscopic and post-operative anterior-posterior radiographs were imported to TraumaCad and calibrated for LLD measurement. LLD was measured on each image using the right-left hip differences in lesser trochanter to pelvic reference line distances. Pelvic reference points included the teardrops and ischia. Fluoroscopic LLD was compared to the gold-standard measurement of LLD measured on a post-operative radiograph. RESULTSMean absolute difference in teardrop referenced LLD between fluoroscopic and post-operative radiographs was 2.17 mm and based on the ischia mean absolute difference was 2.63 mm. Linear regression of fluoroscopic and post-operative radiograph LLD based on teardrop and ischia LLD found r2 values of 0.57 and 0.84, respectively. Mean absolute difference between fluoroscopic and post-operative x-ray LLD was within 5 mm in 95% of cases regardless of pelvic reference.CONCLUSIONThis study demonstrates that a single fluoroscopic view obtained during DAA THA for leg length assessment is clinically useful.

Glossy Appearance Editing for Heterogeneous Material Objects

Abstract With the proliferation of smartphones and social networking services, the opportunities for individuals to take photographs have increased exponentially. In a previous study, the perceived gloss of an object was reduced by its representing as a digital image and compared with a real object. It is also known that image editing, such as lossy image compression, can reduce the glossiness of an image. Therefore, the glossiness of real objects may be easily changed in digital images; thus, a method for appropriately editing the gloss in digital images is required for post-processing. In this study, we propose a gloss appearance editing method for various material objects in a single digital image. The proposed method consists of three steps: color space conversion, gloss detection, and gloss editing. The relationship between the proposed method and the respective reflection models of inhomogeneous objects, metallic objects, and translucent objects was analyzed. Consequently, we determined that the gloss editing of the proposed method is equivalent to editing the specular reflection component of an inhomogeneous object, the grazing reflection component of a metallic object, and the specular reflection component of a translucent object. We applied the proposed method to test images including objects of various materials and confirmed its effectiveness through a subjective evaluation by visual inspection and an objective evaluation using image statistics.

Kyphosis types of the spine cervical-thoracic junction

Introduction. The strengthening of thoracic kyphosis and forward head posture is one of the urgent problems of modern man. Such changes are most often detected for elderly and senile people. However, today these features are also detected for young people. Digital radiography can objectively assess the position of the cervical and thoracic vertebrae. However, the criteria for reliably registering the position of the vertebrae of the cervicalthoracic junction have not yet been developed.The aim of the study — to develop a method for assessing the position of the vertebrae of the cervical-thoracic junction according to digital radiographs; to develop a typology of the vertebra positions of the cervical-thoracic junction; to study the frequency of vertebral position types for the cervical-thoracic junction for different age groups.Materials and methods. Spine X-ray images in the sagittal plane for 141 adult patients with dorsopathies were studied. The selection of patients was random and there were four age groups: 32 persons aged 21 to 45, 32 persons aged 46 to 59, 50 persons aged 60 to 74 and 21 persons aged 75 to 88 year-old. The study was conducted on PC screen, without the patient′s presence. A single digital X-ray image of the spine for each patient in the sagittal plane was obtained. On the combined digital radiograph, the occipital vertical was drawn along all parts of the spine, starting from the external hillock of the occipital bone downwards, and the anteroposterior CV–TV axes of the vertebrae (r axes) were applied. At the points of intersection of the axes with the occipital vertical, the perpendiculars to the axis were restored, and the angles between the perpendiculars and the vertical — the angles of the anteroposterior axes of the vertebrae (r angles) — were measured. Statistical analysis was performed using the MS Offi ce Excel 2007 and Statistica 12 software packages.Results. It was found that the values of the anteroposterior axe angles r of CVII–TIII vertebrae can serve as criteria for determining the spatial position of the cervical-thoracic junction vertebrae. There are 4 types of the shape of the cervical-thoracic junction. Type I is a straightened kyphosis («giraffe neck»); type II is physiological («harmonious»); type III — enhanced kyphosis («bear withers»); type IV–hyperkyphosis («buffalo hump»). Types III and IV are accompanied by a forward displacement of the head. Straightened cervical-thoracic junction kyphosis — type I — was diagnosed in 21 (15 %) people, 52 (37 %) patients were assigned to type II, another 48 (34 %) patients had type III, and 20 (14 %) patients had type IV cervical-thoracic junction kyphosis. In young patients aged 21 to 45, as well as in middle-aged patients aged 46 to 59, the most common type was the harmonious type II of cervical-thoracic junction, in elderly patients aged 60 to 74 — type III and close to it in frequency was type III. In elderly patients aged 75 to 88, the IV type of the position of the vertebrae of the cervical-thoracic junction prevailed in frequency.Conclusion. The proposed diagnostic method allows to register the type of the vertebra positions in cervicalthoracic junction for each patient. Four position types of the cervical-thoracic junction vertebrae were determined: straightened kyphosis «giraffe neck», physiological kyphosis «harmonious», enhanced kyphosis «bear withers» and hyperkyphosis «buffalo hump». Increased kyphosis and hyperkyphosis are accompanied by a forward head posture.

Validity of a 3-compartment body composition model using body volume derived from a novel 2-dimensional image analysis program.

The purpose of this study was: (1) to compare body volume (BV) estimated from a 2-dimensional (2D) image analysis program (BVIMAGE), and a dual-energy x-ray absorptiometry (DXA) equation (BVDXA-Smith-Ryan) to an underwater weighing (UWW) criterion (BVUWW); (2) to compare relative adiposity (%Fat) derived from a 3-compartment (3C) model using BVIMAGE (%Fat3C-IMAGE), and a 4-compartment (4C) model using BVDXA-Smith-Ryan (%Fat4C-DXA-Smith-Ryan) to a 4C criterion model using BVUWW (%Fat4C-UWW). Forty-eight participants were included (60% male, 22.9 ± 5.0 years, 24.2 ± 2.6 kg/m2). BVIMAGE was derived using a single digital image of each participant taken from the rear/posterior view. DXA-derived BV was calculated according to Smith-Ryan et al. Bioimpedance spectroscopy and DXA were used to measure total body water and bone mineral content, respectively, in the 3C and 4C models. A standardized mean effect size (ES) assessed the magnitude of differences between models with values of 0.2, 0.5, and 0.8 for small, moderate, and large differences, respectively. Data are presented as mean ± standard deviation. Near-perfect correlation (r = 0.998, p < 0.001) and no mean differences (p = 0.267) were observed between BVIMAGE (69.6 ± 11.5 L) and BVUWW (69.5 ± 11.4 L). No mean differences were observed between %Fat4C-DXA-Smith-Ryan and the %Fat4C-UWW criterion (p = 0.988). Small mean differences were observed between %Fat3C-IMAGE and %Fat4C-UWW (ES = 0.2, p < 0.001). %Fat3C-IMAGE exhibited smaller SEE and TE, and tighter limits of agreement than %Fat4C-DXA-Smith-Ryan. The 2D image analysis program provided an accurate and non-invasive estimate of BV, and subsequently %Fat within a 3C model in generally healthy, young adults.

Hiding Multi Short Audio Signals in Color Image by using Fast Fourier Transform

Many purposes require communicating audio files between the users using different applications of social media. The security level of these applications is limited; at the same time many audio files are secured and must be accessed by authorized persons only, while, most present works attempt to hide single audio file in certain cover media. In this paper, a new approach of hiding three audio signals with unequal sizes in single color digital image has been proposed using the frequencies transform of this image. In the proposed approach, the Fast Fourier Transform was adopted where each audio signal is embedded in specific region with high frequencies in the frequency spectrum of the cover image to save much more details of the cover image and avoid any doubts that there is any secret information are hidden inside it. The quality of the stego-image and the extracted audio files are evaluated with the standard evaluation metric. The simulation results shown significant results of these metrics and achieve good imperceptibility and high security of the stego-image. The SNR and SPCC values are considered acceptance that means significant in terms quality and similarity of the reconstructed signal.

Buckling developed in 3D printed PLA cuboidal samples under compression: Analytical, numerical and experimental investigations

In this work, the behaviour of short-length PLA 3D printed elements under compression is investigated, with a specific focus on buckling. An extensive experimental campaign is conducted on square polymeric columns produced via Fused Filament Fabrication (FFF), with the longitudinal axis oriented in the out-of-plane direction in 3D printing coordinate system. Compressive and tensile mechanical properties of FFF 3D printed PLA are determined; an asymmetry in out-of-plane tensile-compressive behaviour is discussed. The compression of the specimens is monitored using a single camera Digital Image Correlation system, supported by a preliminary validation of its set-up. The slenderness ratio at which the elements start to buckle is identified. The experimental results are compared with three analytical models for buckling prediction in isotropic materials and with linear and non-linear Finite Elements (FE) models. For a broad range of slenderness ratio, the tangent modulus theory gave a good, if conservative, estimation of the critical loads when used with the compressive mechanical properties. Furthermore, the predictions of the non-linear FE models were found to be consistent with the experimental results. • Compressive and tensile mechanical properties in FFF PLA are compared. • Buckling in FFF PLA short columns is experimentally studied. • DIC is used for buckling identification and monitoring. • Analytical and numerical models are compared with experimental results.

High-throughput measurement of coefficient of thermal expansion using a high-resolution digital single-lens reflex camera and digital image correlation.

High-throughput measurement of thermal deformation and determination of coefficient of thermal expansion (CTE) using a high-resolution digital single lens reflex (DSLR) camera and digital image correlation (DIC) is described. To mitigate the mosaic effect caused by the Bayer filter of DSLR cameras, a color image pre-processing method, which adjusts the brightness and equalizes the color channels of the raw image, is carried out. In addition, a Gaussian pre-filtering step is adopted for denoising the images captured with DSLR cameras to enhance the subpixel registration accuracy. Then, by processing the recorded images using the state-of-the-art DIC algorithm, full-field displacements and strains can be determined. Compared with conventional industrial cameras, a DSLR camera offers not only portability, compactness, and economy but also much higher resolution of recorded images, allowing CTE characterization with higher throughput. Real experiments, including a verification experiment of the color image pre-processing technique, a benchmark CTE determination of Al alloy, and a high-throughput CTE determination of 15 samples of three different metals, validated the feasibility and accuracy of the proposed technique. The proposed method is cost-effective and time-saving, showing great potential in the high-throughput CTE measurement and other high-throughput strain measurement scenarios.

A comprehensive analysis of RHOA mutation positive and negative angioimmunoblastic T-celllymphomas by targeted deep sequencing, expression profiling and single cell digital image analysis.

Angioimmunoblastic T-cell lymphoma (AITL) is a uniquely aggressive mature T-cell neoplasm. In recent years, recurrent genetic mutations in ras homolog family member A (RHOA), tet methylcytosine dioxygenase 2 (TET2), DNA methyltransferase 3 alpha (DNMT3A) and isocitrate dehydrogenase [NADP(+)] 2 (IDH2) have been identified as associated with AITL. However, a deep molecular study assessing both DNA mutations and RNA expression profile combined with digital image analysis is lacking. The present study aimed to evaluate the significance of molecular and morphologic features by high resolution digital image analysis in several cases of AITL. To do so, a total of 18 separate tissues from 10 patients with AITL were collected and analyzed. The results identified recurrent mutations in RHOA, TET2, DNMT3A, and IDH2, and demonstrated increased DNA mutations in coding, promoter and CCCTC binding factor (CTCF) binding sites in RHOA mutated AITLs vs. RHOA non-mutated cases, as well as increased overall survival in RHOA mutated patients. In addition, single cell computational digital image analysis morphologically characterized RHOA mutated AITL cells as distinct from cells from RHOA mutation negative patients. Computational analysis of single cell morphological parameters revealed that RHOA mutated cells have decreased eccentricity (more circular) compared with RHOA non-mutated AITL cells. In conclusion, the results from the present study expand our understanding of AITL and demonstrate that there are specific cell biological and morphological manifestations of RHOA mutations in cases of AITL.

Validity Of A 3-Compartment Body Composition Model Derived From A Single 2-Dimensional Digital Image

Reported Relationships: K. Sullivan: Receipt of Intellectual Property Rights/Patent Holder; Michael Fedewa. Laboratory-based methods for assessing body composition often require specialized equipment, trained administrators, and relatively complex, time-consuming protocols. Simple, accurate, and cost-effective methods to assess body composition in field settings are limited. PURPOSE: The purpose of this study was to evaluate the validity of a digital image derived 3-compartment model estimate of body composition (IMAGE-3C) when compared to a 3-compartment skinfold estimate of body composition (SKF-3C). METHODS: A convenience sample of female participants was recruited for this study (n=24, 20.4±1.0 yrs., 73.1±10.3 kg). Body mass was measured (to the nearest 0.1 kg) with a calibrated digital scale (Tanita BWB-800, Tanita Corporation, Tokyo, Japan), and a standing height was measured (to the nearest 0.1 cm) with a stadiometer (SECA 213, Seca Ltd., Hamburg, Germany). Double measurements (within 2 mm of each other), of skinfold thickness were taken using calibrated skinfold calipers (Lange Skinfold Caliper, Seko, USA) across 7 standard sites on the body. A digital image of each participant was taken from the rear/posterior view using a 12.9 inch, 64g iPad Pro. A paired sample T-test was used to examine potential differences between body composition when measured via IMAGE-3C and SKF-3C. Intraclass Correlations Coefficient (ICC) was used to determine the strength of the association between the two methods. RESULTS: No differences in body composition were observed between IMAGE-3C and SKF-3C (17.9±5.1 versus 18.7±5.6, respectively, p=.08), with excellent agreement between methods (ICC=.96). CONCLUSIONS: The IMAGE-3C model appears to be a valid method of estimating body composition. The ability to evaluate body composition from a single digital image provides an accurate and efficient alternative to laboratory methods, which can be utilized by the general public. Data collection is ongoing. A larger and more diverse sample is needed to confirm these findings.

Test-retest Reliability Of Total Body Volume Derived From A Single 2-dimensional Digital Image

Simple, accurate, and cost-effective methods to estimate body composition in field settings are valuable to practitioners and clinicians. An automated smartphone- or tablet-based method of determining body composition from a single 2-dimensional (2D) digital image has recently been developed. However, the test-retest reliability has yet to be determined. PURPOSE: The purpose of this study was to evaluate the test-retest reliability of total body volume (BV) estimated from a single 2D digital image. METHODS: A convenience sample was recruited for this study (n=30, 21.0±3.1 yrs., 86.7% female, 24.8±3.0 kg/m2). Body mass was measured (to the nearest 0.1 kg) with a calibrated digital scale (Tanita BWB-800, Tanita Corporation, Tokyo, Japan). Standing height was measured (to the nearest 0.1 cm) with a stadiometer (SECA 213, Seca Ltd., Hamburg, Germany). Two digital images of each participant were taken from the rear/posterior view using a 12.9 inch, 64g iPad Pro. A paired sample T-test was used to examine differences between BV obtained from the images (BV1, BV2). An Intraclass Correlations Coefficient (ICC) assessed the strength of the association between BV1 and BV2. RESULTS: No differences were observed between BV1 and BV2 (71.2±12.0 L versus 71.1±11.7 L, respectively, p=0.51), with excellent agreement between the two measures (ICC=0.99). CONCLUSIONS: This novel method of acquiring BV produced near-perfect reliability within our small sample. Given the excellent reliability, future research should examine the validity of acquiring body composition from a single 2D digital image using an automated smartphone- or tablet-based application.

SIF determination in finite double-edge cracked orthotropic composite using J-integral and digital image correlation

This paper demonstrates ability to evaluate the stress intensity factor in a double-edge cracked finite [013/905/013] graphite-epoxy orthotropic tensile composite from J-integral and a single digital image correlation recorded displacement field. Relevant stress/strain/displacement information is obtained by processing the measured displacement data with stress functions, conformal mapping and analytical continuation method. A normalized stress intensity factor of 2.05 is determined experimentally for the present geometry, loading and material. Plane-stress is assumed. The technique is not restricted to a laboratory environment and concepts are applicable to other structural shapes, loads and crack configurations. Unlike purely numerical or theoretical approaches, the present method does not require knowing the external loading. This is significant as loads are often unknown in practice. Results are verified independently.

Predicting pregnancy test results after embryo transfer by image feature extraction and analysis using machine learning

Assessing the viability of a blastosyst is still empirical and non-reproducible nowadays. We developed an algorithm based on artificial vision and machine learning (and other classifiers) that predicts pregnancy using the beta human chorionic gonadotropin (b-hCG) test from both the morphology of an embryo and the age of the patients. We employed two high-quality databases with known pregnancy outcomes (n = 221). We created a system consisting of different classifiers that is feed with novel morphometric features extracted from the digital micrographs, along with other non-morphometric data to predict pregnancy. It was evaluated using five different classifiers: probabilistic bayesian, Support Vector Machines (SVM), deep neural network, decision tree, and Random Forest (RF), using a k-fold cross validation to assess the model’s generalization capabilities. In the database A, the SVM classifier achieved an F1 score of 0.74, and AUC of 0.77. In the database B the RF classifier obtained a F1 score of 0.71, and AUC of 0.75. Our results suggest that the system is able to predict a positive pregnancy test from a single digital image, offering a novel approach with the advantages of using a small database, being highly adaptable to different laboratory settings, and easy integration into clinical practice.

Фрактальний аналіз як морфометричний метод у морфології: спосіб дилатації пікселів при дослідженні цифрових зображень анатомічних структур

Розроблено метод дилатації пікселів для розрахунку фрактального індексу мозочка людини за даними магнітно-резонансної томографії. Для дослідження використовують фрагмент цифрового зображення (томограми) мозочка. Зображення калібрують, його фрагмент копіюють у програму Adobe Photoshop CS5, де створюють окреме цифрове зображення з розмірами та роздільною здатністю 2n пікселів на дюйм, де n – кількість етапів підрахунку фрактального індексу. Зображення контрастують і поетапно підраховують фонові, «порожні» та «заповнені» пікселі, що містять фрагменти досліджуваної структури. На кожному етапі вчетверо збільшують розмір одного пікселя і, таким чином, удвічі зменшують роздільну здатність зображення (із 64 пікселів на дюйм до 32, 16, 8, 4 та 2 пікселів на дюйм). За кількістю пікселів, що містять фрагменти досліджуваної структури, і розмірами пікселя відносно загальної площі зображення (box size) обчислюють фрактальний індекс мозочка.

Simplifying of DLT Equations for a Single Digital Image and its Application in Architectural Façades Documentation

Survey of architectural façades to obtain elevation drawings is an essential, especially in case of maintenance, restoration, ...etc. On the other hand, the rapid progress of the obtained image size captured by digital cameras opens new areas for the captured images to be used in photogrammetry. One of these new areas is the use of a single digital image for surveying and recording of architectural façades. So, the main objective of the current research is to develop a computer algorithm using least squares adjustment method for studying the practical visibility, applicability, and accuracy of using a single digital image captured by a digital camera in surveying architectural façades. To achieve the above-mentioned goal, simplified formulas obtained from collinearity condition, the basis of the Direct Linear Transformation model (DLT), to suit the architectural façades conditions, which is the façade lies in one vertical plane. The obtained formulas showed that eight transformation parameters are required (needed) between the architectural façade and the captured image. Hence, the eight parameters can be computed using four common points or more. So, two field experiments were made on two architectural façades to test the practical visibility, applicability, and accuracy of the supposed technique. The obtained results proved the success of the supposed technique and its related computer algorithm in the survey and the record of the vertical architectural façades.