Standard Digital Image Research Articles

A Comparative Study to Check the Accuracy of Tooth Shade Selection With Standardized Digital Photographs and a Spectrophotometer.

The success of any dental prosthesis depends on aesthetics and function. A proper shade selection is a prime requisite for providing aesthetics to dental patients. This study aims to compare the photographic method of shade selection with that of a digital spectrophotometer. The study included 50 participants. The primary inclusion criterion was the presence of the maxillary left central incisor without a history of restorative or endodontic procedures. The shade of the left maxillary central incisor was determined using the VITA Easyshade V spectrophotometer (VITA Zahnfabrik, BadSäckingen, Germany) and the digital photography method for all the selected participants. The CIELAB colour space utilizes three values (L*, a*, and b*) to objectively measure colour. While the digital photography approach used Adobe Photoshop software (Adobe Systems Incorporated, San Jose, CA) to report solely the L*, a*, and b* values, the spectrophotometer reported the L*, a*, and b* values along with the actual shade. After obtaining the values of L*, a*, and b*, ΔE, which is their difference, was calculated using a standard formula. Statistical analysis was carried out by using Student's t-test and proportion z-test. When the comparison of the L*a*b* values was done, Student's t-test showed similar (P>0.05) L(t=0.16, P=0.872), a (t=0.52, P=0.607), and b (t=0.23, P=0.820) values between the two groups; that is, they did not differ significantly or showed perfect matching. There was agreement (ΔE≤2) in 42 (84.0%) cases and disagreement (ΔE>2) in eight (16.0%) cases. The proportion z-test showed an agreement of 84.0%, which was statistically highly significant (z=20.44, P<0.001). The true shade of the teeth can be depicted using standardized digital images.

Correlation between different points on the face and the width of maxillary anterior teeth

Statement of problemThere is currently no consensus on the relationship between maxillary anterior teeth and different facial anthropometric measurements. Additionally, whether these relationships vary by age and sex remains unreported. PurposeThis clinical study aimed to investigate the relationship between the intercanine distance (ICaD) and intercanthal distance (ICD), interpupillary distance (IPD), interalar width (IAW), and intercommissural width (ICW), and to compare whether these relationships differ between different age and sex populations. Material and methodsParticipants (n = 409) were enrolled according to the inclusion criteria, and their standardized digital images were taken to measure facial and oral segments through an image processing program. The differences between ICaD and four facial measurements and the sexual differences for all measurements were compared using the 1-sample t-test. The differences among different age groups for all measurements were compared using the one-way analysis of variance (ANOVA) test, and a least significant difference (LSD) test was used for multiple comparisons. The association between ICaD and the four facial measurements was evaluated using Pearson correlation analysis. The correlation between ICaD and four facial measurements was evaluated using linear regression. Differences in regression equations among the subgroups were evaluated through subgroup regression analysis and the significance test of the difference between the two regression coefficients. Tests of significance were two-sided, with alpha level of 0.05. The reliability of the results was evaluated by calculating intraclass correlation coefficients. ResultsThe ICD, IPD, ICW, and IAW significantly differed from the ICaD in both sexes (P < 0.01). All measurements were significantly greater in men than in women (P < 0.01). The differences among the age groups were statistically significant for all measurements except IPD (P < 0.05). A significant positive correlation was found between all facial measurements (r = 0.258 [ICD], r = 0.334 [IPD], r = 0.389 [ICW], and r = 0.393 [IAW]) and the ICaD in both sexes. The highest correlation was found between ICW(r = 0.345) and ICAD in men and IAW (r = 0.285) and ICAD in women. Except for the 20–29 and 50–59 age groups, the mathematical equations of ICaD and facial anthropometric measurements differed among the other age groups and sexes. ConclusionsICD, IPD, ICW, and IAW cannot be directly used to determine ICaD in both sexes. Nevertheless, when observed from the frontal aspect, by the use of digital images, all facial measurements correlated to the intercanine distance, with a high probability. The mathematical formulae combined with facial anthropological measurements can help ensure the combined width of the six maxillary anterior teeth, but the effects of sex and age differences should be considered.

Coronal, Sagittal, and Horizontal Classification of the Chest Shape and Its Role in Selection of Proper Implants.

The number of female breast correction procedures has been steadily increasing. Despite extensive literature being available on these procedures, few authors have discussed the role of preoperative chest wall analysis in relation to postoperative outcomes. To date, no comprehensive classification of chest shape has been introduced in the literature. The aim of this study was to present a novel classification of chest shapes, based on three basic planes: coronal (C), sagittal (S), and horizontal (H), hence the proposed name "CSH classification." In this study, a retrospective analysis of 1000 randomly selected chest and breast images was conducted by three independent nonmedical evaluators, using standardized digital images captured with the Vectra 3D body scanner. All examined patients were qualified for breast augmentation surgery. Among 1000 randomly examined patients, 923 were classified in the coronal plane, 920 in the sagittal plane, and 627 in the horizontal plane. Other patients were excluded from the study due to insufficient quality of the images. A notable 43.2% of women have shoulder height asymmetries. A relationship between shoulder height asymmetry and chest width was confirmed by the chi-square Pearson test (P = 0.04), indicating that a higher shoulder is associated with a greater chest width on the same side. Furthermore, 84.7% of women displayed excessive upper chest projection, whereas 28.4% showed excessive lower chest projection. Additionally, 84.4% of women had chest projection asymmetries. The vast majority of the women had natural asymmetries of the breast or and chest wall. The CSH classification allows systematizing the chest shape assessment. The chest shape has a significant impact on breast implant selection and the choice of the breast surgery technique.

Three-dimensional modeling and defect quantification of existing concrete bridges based on photogrammetry and computer aided design

Bridge infrastructure is aging and deteriorating and requires innovative condition monitoring and assessment to ensure safety and maintain serviceability. Current practices for bridge condition assessment depend mainly on visual inspection. Innovative data collection technologies can assist in bridge inspection and defect identification and circumvent the limitations of traditional visual inspection. This research aims to apply photogrammetry principles and image processing techniques to develop a full-scale three-dimensional (3D) bridge structure model for defect identification and quantification. The data source to establish the point cloud models is a set of digital images taken at the bridge site. The point cloud models are developed by analyzing high-resolution images captured using a Nikon D4S camera. The images are captured from different positions/locations to provide extensive stereo coverage and maximum overlapping. Two hundred images of the bridge are processed with PhotoModeler software along with the calibration information, and ground control points (GCPs) coordinates to create the models. A standard digital close-range image processing is implemented to generate the 3D points cloud model. The calibration and orientation processes are made over a deformed situation. However, the developed CAD bridge drawings depict the original undeformed geometry. The extracted bridge inventory data from the 3D model, including bridge geometry information and bridge damage quantification, can provide a baseline for the bridge monitoring system to detect bridge deterioration over the years. The developed photogrammetric 3D model has an RMSE of 0.0081 m and uncertainty of ± 0.0041 m. Future research can aim at developing reusable parametric objects for bridges in Revit and coding scripts using programming languages such as Dynamo or Python to perform further analysis of the captured information.

Facial Angles in Arabian Women Seeking Rhinoplasty.

The purpose of this study is to determine the average values of the angular nasal anthropometric variables in Arabian women seeking rhinoplasty and compare them with the normal values. A total of 150 female patients, who underwent rhinoplasty between January 2018 and November 2021, were enrolled in this study. The exclusion criteria were a history of nasal trauma, previous rhinoplasty, and a cleft nose. Data were obtained from standardized digital photographic images. Lateral and basal views were analyzed using landmarks defined by a single observer and measurements were performed using Adobe Photoshop Software SC6. All data were analyzed using SPSS version 21 software (IBM) and compared with the normal values obtained from a previous study. All facial angles, except for the nasofrontal angles, were significantly different between the surgical and nonsurgical normal groups. The values (means±SDs) in the surgical group were as follows: nasofacial angle, 29.7±3.4 degrees; nasofrontal angle, 146.2±2.8 degrees; glabella-nasal angle, 169.8±5.8 degrees; nasolabial angle, 113.5±11 degrees; nasomental angle, 130.6±6 degrees; nasal tip angle, 102.3±8 degrees; ala-slope angle, 95.4±13.6 degrees. The nose characteristics of Arabian women seeking rhinoplasty were as follows: (1) shallow radix, (2) under the projected tip, and (3) normal tip rotation. Surgical planning is important upon consideration of any procedure or modification of the nose among Arabian women.

Improved exploiting modification direction steganography for hexagonal image processing

Steganography has made significant advances in the Square-pixel-based Image Processing (SIP) domain, but to our knowledge, no work has yet been done in Hexel (Hexagonal Pixel)-based Image Processing (HIP). This paper presents a HIP-domain data hiding method that exploits and improves the SIP-domain Exploiting Modification Direction (EMD) embedding scheme. The proposed method, Hexagonal EMD (HexEMD), utilizes a HIP-domain cover image's hexagonal nature and infrastructure to embed the secret message. In standard digital imaging systems, the sensor portion that converts photonic energy into an analog electrical signal and all the subunits that digitize, process, and display this signal are based on square pixel logic, so there is currently no commercial equipment available to produce HIP-domain images. Thus, the image is first transformed into the HIP domain in software using the infrastructure developed in the project. Then the HIP-domain image is partitioned into non-overlapping heptads of the standard size, each containing seven hexels. Rather than embedding segments to the independent pixel pairs as done in SIP-domain EMD, we do the embedding iteratively in each heptad. Experimental results show that the HexEMD outperforms its SIP equivalent, EMD, by improving embedding capacity and achieving low visual quality distortion.

33691 Prospective pilot evaluation in Fitzpatrick skin phototypes III to VI of a crystal-free brush-tip exfoliation device with variable vacuum pressure and skin infusion for hyperpigmentation

Unmet needs in skin of color include satisfactory long-term treatments for hyperpigmentation, whether primary or a sequela of various dermatoses. Surveys report that pigmentary disorders are the second most common dermatoses among African American patients consulting dermatologists, and that hyperpigmentation significantly impairs quality of life. This single-center, open-label pilot evaluation prospectively assessed safety, efficacy and tolerability in patients with Fitzpatrick skin phototypes III to VI of an FDA 510(k)-cleared crystal-free brush-tip exfoliation device with adjustable vacuum pressure and skin infusion containing 1% each of alpha-arbutin, glutathione, kojic acid plus azelaic acid; lactic acid; and salix alba bark extract. 23 female patients aged 26 to 71 with mild, moderate or severe facial hyperpigmentation received 3 to 6 treatments at 2 to 4 weekly intervals. Patients applied broad spectrum sunscreen daily. Three weeks after the third treatment, blinded assessment of standardized digital images found that all patients had improvements in skin tone, texture and brightness/radiance (≥2 points on 10-point scales), and 15 (65%) had ≥1 point improvement in pigmentation. Physician and patient GAIS scoring ranged from Improved to Very Much Improved. DQLI improved for 12 (52%). The procedure was well tolerated, with no significant adverse effects. Post-procedural erythema lasted 15 minutes to under 24 hours. All patients reported satisfaction with treatment and increased These pilot data show safety, efficacy and tolerability in skin of color. The ability to patient-tailor all procedural steps, including exfoliation depth, magnitude of vacuum pressure and infusion type, may confer benefits over conventional aluminum oxide crystal microdermabrasion.

Mechanical Characteristics Evaluation of a Single Ply and Multi-Ply Carbon Fiber-Reinforced Plastic Subjected to Tensile and Bending Loads.

Carbon fiber-reinforced composites represent a broadly utilized class of materials in aeronautical applications, due to their high-performance capability. The studied CFRP is manufactured from a 3K carbon biaxial fabric 0°/90° with high tensile resistance, reinforced with high-performance thermoset molding epoxy vinyl ester resin. The macroscale experimental characterization has constituted the subject of various studies, with the scope of assessing overall structural performance. This study, on the other hand, aims at evaluating the mesoscopic mechanical behavior of a single-ply CFRP, by utilizing tensile test specimens with an average experimental study area of only 3 cm2. The single-ply tensile testing was accomplished using a small scale custom-made uniaxial testing device, powered by a stepper motor, with measurements recorded by two 5-megapixel cameras of the DIC Q400 system, mounted on a Leica M125 digital stereo microscope. The single-ply testing results illustrated the orthotropic nature of the CFRP and turned out to be in close correlation with the multi-ply CFRP tensile and bending tests, resulting in a comprehensive material characterization. The results obtained for the multi-ply tensile and flexural characteristics are adequate in terms of CFRP expectations, having a satisfactory precision. The results have been evaluated using a broad experimental approach, consisting of the Dantec Q400 standard digital image correlation system, facilitating the determination of Poisson’s ratio, correlated with the measurements obtained from the INSTRON 8801 servo hydraulic testing system’s load cell, for a segment of the tensile and flexural characteristics determination. Finite element analyses were realized to reproduce the tensile and flexural test conditions, based on the experimentally determined stress–strain evolution of the material. The FEA results match very well with the experimental results, and thus will constitute the basis for further FEA analyses of aeronautic structures.

Compact MAX and MIN Stochastic Computing architectures

In this work we present Stochastic Computing MAX and MIN architectures. Their operation relies on an accumulator to store the signed-bit differences between their two stochastic input sequences without additional randomization. This counting process makes their operation deterministic, resulting in an improved latency-accuracy trade-off when compared to existing Stochastic Computing MAX and MIN architectures. Modeling the architectures as Markov Chains allows for an in-depth analysis of their stochastic operation, derivation of their statistical properties and proof of their correct operation. An overflow/underflow Markov Chain model allows for the analytic calculation of the register size they use, providing guidelines for its selection based on accuracy requirements. The performance of the proposed architectures is compared to those of existing ones in the Stochastic Computing literature in computational accuracy and hardware resources using MATLAB and Synopsys Tools. Their effectiveness is demonstrated in two standard Digital Image Processing tasks; image denoising with a 3 × 3 median filter and dimensionality reduction of an image with a 2 × 2 max pooling kernel.

Evaluation of image registration for measuring deformation fields in soft tissue mechanics

AbstractHigh‐fidelity biomechanical models usually involve the mechanical characterisation of biological tissues using experimental methods based on optical measurements. In most experiments, strains are evaluated based on displacements of a few markers and represents an average within the region of interest (ROI). Full‐field measurements may improve description of non‐homogeneous materials such as soft tissues. The approach based on non‐rigid image registration is proposed and compared with standard digital image correlation (DIC) on a set of samples, including (i) complex heterogeneous deformations with sub‐pixel displacement, (ii) a typical uniaxial tension test of aorta, and (iii) an indentation test on skin. The possibility to extend the ROI to the whole sample and the exploitation of a natural tissue pattern represents the main assets of the proposed method whereas the results show similar accuracy as standard DIC when analysing sub‐pixel deformations. Therefore, displacement and strain fields measurement based on image registration is very promising to characterise heterogeneous specimens with irregular shapes and/or small dimensions, which are typical features of soft biological tissues.

Digital Image Correlation for stereoscopic measurement of water surface dynamics in a partially filled pipe

This paper presents a novel method for measuring three-dimensional (3D) water surface dynamics in a partially filled pipe. The study on investigation of the 3D free surface dynamics in partially filled pipes is very limited. The method involves tinting the water white with titanium dioxide so that the water surface appears like a solid surface to image-based measuring systems. This method uses a high-resolution projector to project a stochastic pattern of light onto the water surface and uses two high-resolution cameras to capture the pattern on the deformed water surface. The 3D instantaneous water surface fluctuation can be computed from the images captured by the two cameras using a standard Digital Image Correlation algorithm. It is demonstrated that the surface dynamics parameters of turbulent flow in partially filled pipes, including surface fluctuations and surface velocity, can be measured using the projector, high-resolution cameras and DIC algorithm.

Fast subpixel displacement measurement, part 1: one-dimensional analysis, simulation, and experiment

Many image processing applications require a quantitative estimation of the underlying correspondence (of the relative position in space) between two or more images. Here, we propose a unique, less numerically intensive method, which we refer to as the subtraction method (SM), to measure in-plane object motion with subpixel accuracy. This method can be usefully employed in conjunction with the correlation method (CM) to provide fine motion information very quickly (∼100 times faster). We first review the CM, then, demonstrate, explain, and examine the proposed SM using analytic functions, standard digital images, and using both simulated and experimental data. Specifically, subpixel motion results for Gaussian functions, four different standard images, and speckle images are examined. Performance is compared to that of the CM. Experimentally, images are captured using both optical and THz imaging systems. A high-resolution megapixel camera is used in the optical system and a low-resolution camera with 16 × 16 pixels is used to perform the THz measurements. One-dimensional subpixel motion in both x and y is examined and analyzed. The results demonstrate that the method can be flexibly used in different areas.

Digital photography in the evaluation and management of female patients with congenital adrenal hyperplasia: A standardized protocol for quality improvement

Digital photography can be securely stored in the medical record and enhance documentation of physical exam findings and monitor wound healing. A standardized protocol that respects the dignity of the patient and maintains the fidelity of objective documentation is needed for patients with differences in sexual development (DSD) and congenital adrenal hyperplasia (CAH). The purpose of this study was to evaluate the feasibility, acceptability, and applications of a HIPAA-compliant digital photography protocol in the care of female patients with CAH. A protocol for standardized digital imaging including consent, permission, data capture, and storage in the electronic medical record (EMR) was implemented. Patients undergoing physical examination during multidisciplinary CAH clinic visits, preoperative evaluation, and postoperative follow-up from October 2020 through May 2021 were included. Male patients with CAH, patients with clitoromegaly or urogenital sinus not from CAH, and patients seen through telehealth were excluded. Consent was obtained from caregivers and permission from patients. Images of the exam were taken during clinic visits or at the time of surgery with no identifying features included. Images were directly uploaded into the patient's chart in the HIPAA-protected EMR separate from other clinical documentation and not stored on personal devices. There were 17 patients with CAH seen with median age 6 years (range 2 weeks-18 years). There was a median of 3 photos per patient during the study period with cooperation from both the patient and their caregiver. Amongst the patients seen, 6 patients underwent reconstruction with a median of 10 photos per patient. Images were available and used for preoperative planning and counseling. Patients with previous images did not require repeat examinations and were subjected to fewer genital examinations. Fewer providers were present during exams. Images taken by providers and caregivers during the postoperative period were used to monitor wound healing and surgical outcomes. Protocol implementation improved patient care by reducing the number of exams and number of providers present, enhancing clinical documentation, and providing a means of tracking the physical exam over time. This was in concordance with guidelines for limiting exams for patients with DSD and CAH. Implementation of best practices for medical photography was important in respecting patient dignity and confidentiality. Implementation of standardized digital photography was feasible and acceptable to patients and caregivers. Digital images reduced the need for repeat physical examination and provided a visual means of enhancing clinical documentation.

Three-Dimensional (3D) Stereolithographic Tooth Replicas Accuracy Evaluation: In Vitro Pilot Study for Dental Auto-Transplant Surgical Procedures.

After immediate tooth extraction or after alveolar socket healing, tooth transplants are increasingly used for functional restoration of edentulous maxillary areas. Recent studies have shown the periodontal ligament (PDL) viability and the tooth housing time in the adapted neo-alveolus as key factors for transplantation success. During surgical time, 3D stereolithographic replicas are used for fitting test procedures. In this paper, the accuracy of 3D dental replicas, compared with the corresponding natural teeth, is assessed in surgical transplantation. Lamb skulls were selected and submitted to Cone Beam Computer Tomography (CBCT). Scanning information, converted into Standard Digital Imaging and Communications in Medicine (DICOM) and Standard Triangulation Language (STL), was sent to the Volux X-ray Centre for 3D replica printing. After the tooth extractions, all lambs’ incisors were measured with a digital caliber and compared with the 3D replicas. Volume and dimensional error values were evaluated. All replicas showed macroscopically smaller volume (45.54%). Root replicas showed higher variations compared with the crown areas, with several unreplicated apical root areas. The cement–enamel junction tooth area was replicated quite faithfully, and the base area relative error showed 9.8% mean value. Even further studies with a larger number of replicas are needed. Data obtained confirmed high volumes of macroscopic discrepancies with several unreproduced apical root sites. The achieved accuracy (90.2%) confirmed that the 3D replicas cannot be used to reduce the surgical time during transplantation predictable procedures.

PRESS and Piezo Microsurgery (Bony Lid): A 7-Year Evolution in a Residency Program—Part 2: PRESS-Defined Site Location

IntroductionTreatment of a failing endodontic procedure via microsurgical revision presents better outcomes due, in part, to the integration of the surgical operating microscope and cone-beam computed tomography into clinical practice. However, challenges still remain with respect to the operational locations and the techniques required to address them. Posterior sites, with substantial cortical plate thicknesses and sensitive anatomy, present the dichotomy of visualization versus postsurgical regeneration of bone. The bony lid technique bridges the gap between these 2 concepts, and the application of piezosurgery renders a precise and biocompatible osseous incision. The purpose of this article was to outline through case reports the progression of piezo-guided surgery in a resident setting. MethodsThe first 2 evolutions of the technique used a surgeon-defined method for site location. This third and final evolution uses a digital workflow to virtually plan the surgical procedure, integrating Standard Tessellation Language and Digital Imaging and Communication in Medicine files to create 3-dimensional guides with exacting resection locations, levels, and angles. Export of the virtually planned guide in postproduction generates the precision endodontic surgical stent to accurately define the site location and parameters of the procedure. All surgeries were executed using the piezosurgical method with increasing levels of guidance and precision throughout the evolution process. ResultsEach step in the technique implementation enabled the resident to assimilate a new technique and skill set while maintaining bone architecture and minimizing volume loss postoperatively. The patient benefits were an increase in intraoperative safety and postoperative comfort. The resident benefits were accelerated regeneration timetables and increases in the confidence level of the resident and the number of scheduled posterior surgical procedures. ConclusionsThe progression from crude on-site measurements to elegant and precise surgical guides enabled the access and manipulations of difficult surgical sites without compromising visibility, postoperative osseous regeneration, or patient comfort.

All-in-focus fine needle aspiration biopsy imaging based on Fourier ptychographic microscopy

ContextCytology is the study of whole cells in diagnostic pathology. Unlike standard histologic thinly sliced specimens, cytologic preparations consist of preparations of whole cells where cells commonly cluster and aggregate. As such, cytology preparations are generally much thicker than histologic slides, resulting in large patches of defocus when examined under the microscope. A diagnostic aggregate of cells often cannot be viewed in focus together, requiring pathologists to continually manipulate the focal plane, complicating the task of accurately assessing the entire cellular aggregate and thus in making a diagnosis. Further, it is extremely difficult to acquire useful uniformly in-focus digital images of cytology preparations for applications such as remote diagnostic evaluations and artificial intelligence models. The predominant current method to address this issue is to acquire digital images at multiple focal planes of the entire slide, which demands long scanning time, complex and expensive scanning systems, and huge storage capacity. AimsHere we report a unique imaging method that can acquire cytologic images efficiently and computationally render all-in-focus digital images that are highly compact. Methods and materialThis method applies a metric-based digital refocusing to microscopy data collected with a Fourier ptychographic microscope (FPM). The digitally refocused patches of images are then synthesized into an all-in-focus image. ResultsWe report all-in-focus FPM results of thyroid fine needle aspiration (FNA) cytology samples, demonstrating our method’s ability to overcome the height variance of 30 μm caused by cell aggregation, and rendering images at high resolution (corresponds to a standard microscope with objective NA of 0.75) and that are all-in-focus. ConclusionsThis technology is applicable to standard microscopes, and we believe can have an impact on diagnostic accuracy as well as ease and speed of diagnosing challenging specimens. While we focus on cytology slides here, we anticipate this technology’s advantages will translate well for histology applications. This technique also addresses the issue of remote rapid evaluation of cytology preparations. Finally, we believe that by resolving the focus heterogeneity issues in standard digital images, this technique is a critical advance for applying machine learning to cytology specimens.

Evaluation of long-term stability of curve of Spee levelled with continuous archwires in two different retention protocol

Objectives: The objectives of the study were to assess the long-term stability of the curve of Spee leveled with continuous archwire in subjects with two different retention protocols. Materials and Methods: The study sample consisted of 20 patients (mean age 18 ± 2 years) presenting with curve of Spee depth of =/&gt; 3 mm. For each subject, lateral cephalograms and dental casts were available before treatment (T1), at the end of orthodontic therapy (T2), and 1 year after the end of treatment (T3). All subjects were divided into two groups according to their retention protocol – fixed retainer group (Group-1) and Essix retainer group (Group-2). Cephalometric parameters were used to evaluate the dental movements after treatment. Curve of Spee depth was measured on standardized digital images of casts. Results: In multicomparison table, it shows that there was a statistically significant difference (P = 0.032) between Spee-T2 and Spee-T3 and there was no statistical difference (P = 0.159) between L1MP-T2 and L1MP-T3 in fixed retainer group. In Essix retainer group, no changes were observed from L1MP-T2 to L1MP-T3 and there was a non-significant difference found between Spee-T2 and Spee-T3. Conclusion: In Group-1 (fixed retainer), there is some amount of relapse or extrusion of lower incisor. In Group-2 (Essix retainer), there was not any change in the position of the lower incisor, which suggests that occlusal coverage of the Essix retainer does not allow any extrusion and retains the curve of Spee.

Comparative Analysis of an Efficient Image Denoising Method for Wireless Multimedia Sensor Network Images in Transform Domain

In recent years, there has been an increasing research interest in image de-noising due to an emphasis on sparse representation. When sparse representation theory is compared to transform domain-based image de-noising, the former indicates that the images have more information. It contains structural characteristics that are quite similar to the structure of dictionary-based atoms. This structure and the dictionary-based method is highly unsuccessful. However, image representation assumes that the noise lack such a feature. The dual-tree complex wavelet transform incorporates an increase in transform data density to reduce the effects of sparse data. This technique has been developed to decrease the image noise by selecting the best-predicted threshold value derived from wavelet coefficients. For our experiment, Discrete Cosine Transform (DCT) and Complex Wavelet Transform (CWT) are used to examine how the suggested technique compares the conventional DCT and CWT on sets of realistic images. As for image quality measures, DT-CWT has leveraged superior results. In terms of processing time, DT-CWT gave better results with a wider PSNR range. Further, the proposed model is tested with a standard digital image named Lena and multimedia sensor images for the denoising algorithm. The suggested denoising technique has delivered minimal effect on the MSE value.

Monitoring and Assessment of Land Use/Land Cover Changes in Elgezira-Aba Locality, White Nile State, Sudan using geospatial technology

Desertification as major environmental problem in Sudan seriously affected the livelihood and food security of population. Poor land use and climatic variability are the major causes of the desertification. This study focused on assessing and mapping of chanes land use and land cover (LU/LC) as drivers to desertification processes in the ElGezira-Aba Locality, White Nile State, Sudan. Two images (173/51) acquired by ETM+ and OLI/TIRS for years 2000 and 2016 were analyzed. Standard digital image processes were performed including layer stacking, supervised image classification, area calculation, accuracy assessment and post-classification change detection. In the years 2000 and 2016, respectively, forest covered 3838 Ha(15 %) and 1449 Ha (5.9 %), open forest covered 2749 Ha (11 %) and 1085 Ha (4.5%), grassland covered 2354 Ha (10 %) and 1315 Ha (5.4 %), rainfed mechanized agriculture covered 377 Ha (2 %) and 1914 Ha (8 %), irrigated scheme covered 2255 Ha (9 %) and 5051 Ha (20.8 %), fallow land covered 3791 Ha (5 %) and 1577 Ha (6 %), bareland covered 3938 Ha (16 %) and 1425 Ha (5.9 %), sand dunes covered 998 Ha (4 %) and 1165 Ha (4.8 %), water bodies covered 2219 Ha (9 %) and 3605 Ha (14 %) and urbanization covered 1794 Ha (7 %) and 5698 Ha (23 %). Overall classification accuracies for years 2000 and 2016, respectively were 86.39 % and 87.89 %, while overall kappa statistics were 0.8452 and 0.8594. Pronounced decrease in vegetation cover (forest, open forest and grassland) was recorded in favors of agriculture (irrigated scheme, rainfed mechanized agriculture)and urbanization. Sand dunes and Water bodies were increased. The dominant desertification processes were vegetation deterioration and wind erosion as a result of inappropriate agricultural activities, overgrazing and expansion of urban areas. The study concluded the necessity of protection natural resources by adoption of proper urban and land use planning in addition to use of geospatial technologies in monitoring of these resources.

Nonscaling Adders and Subtracters for Stochastic Computing Using Markov Chains

This work presents adder and subtracter architectures for stochastic computing (SC). In contrast to standard approaches, the result of their operation is nonscaling, i.e., X ± Y, and this is achieved via a deterministic operation based on a counting process. These properties result in an improved tradeoff between accuracy and stochastic sequence length, fast convergence, and the potential for cascaded, scale-dependent (e.g., nonlinear) stochastic computations providing with flexibility on the design level. The architectures are modeled using Markov chains (MCs) allowing for detailed understanding of their proper operation supported with analytical derivations. Using modified MC models, the adder and subtracter's internal register size is analytically calculated providing guidelines for its optimal size selection based on accuracy requirements and stochastic input sequences lengths. Both architectures are simulated in MATLAB and are designed in Synopsys to compare their performance to that of existing ones in terms of computational accuracy and hardware resources. Finally, to demonstrate the adder's efficacy, we use it as a building block to realize a 3×3 convolution kernel and then perform a standard digital image processing task. The results are compared to those achieved using adder architectures from the SC literature.