Three-dimensional Image Processing Research Articles

Automated three-dimensional image processing for 2-blastomere and 4-blastomere embryo surgical applications

Automated three-dimensional image processing for 2-blastomere and 4-blastomere embryo surgical applications

3D reconstructions, 4D imaging and postprocessing with CT in musculoskeletal disorders: Past, present and future

Three-dimensional (3D) imaging and post processing are common tasks used daily in many disciplines. The purpose of this article is to review the new postprocessing tools available. Although 3D imaging can be applied to all anatomical regions and used with all imaging techniques, its most varied and relevant applications are found with computed tomography (CT) data in musculoskeletal imaging. These new applications include global illumination rendering (GIR), unfolded rib reformations, subtracted CT angiography for bone analysis, dynamic studies, temporal subtraction and image fusion. In all of these tasks, registration and segmentation are two basic processes that affect the quality of the results. GIR simulates the complete interaction of photons with the scanned object, providing photorealistic volume rendering. Reformations to unfold the rib cage allow more accurate and faster diagnosis of rib lesions. Dynamic CT can be applied to cinematic joint evaluations a well as to perfusion and angiographic studies. Finally, more traditional techniques, such as minimum intensity projection, might find new applications for bone evaluation with the advent of ultra-high-resolution CT scanners. These tools can be used synergistically to provide morphologic, topographic and functional information and increase the versatility of CT.

Gradient-based fibre detection method on 3D micro-CT tomographic image for defining fibre orientation bias in ultra-high-performance concrete

Ultra-high-performance fibre reinforced concrete (UHPC) is a class of advanced cementitious composites characterized by its high compressive and flexural strengths, toughness and enhanced durability. The mechanical properties of the UHPC are to a great extent dependent on fibre volume fraction, orientation and distribution within the cementitious matrix. However, determination of the true three-dimensional fibre orientation and distribution is challenging. In this paper micro-computed tomography (micro-CT) is used to determine these parameters. Cylindrical samples of UHPC were extracted from a dogbone tension test specimen and from a pretensioned bridge girder, and high-resolution micro-CT images were then acquired. Using the scanned data, and following three-dimensional image reconstruction and image processing, quantitative fibre information was obtained via a novel image post-processing technique based on local-intensity gradient significantly improving cross-fibre detection compared to existing techniques. The estimated fibre volume fraction is close to design and experimentally measured values. Straight and hooked end fibres in UHPC sample were successfully identified and segmented using this novel technique. The test results show the fibre arrangement to be highly anisotropic with fibres aligned predominantly in one direction, which is attributed to the casting processes and flow.

Calibration of multiple sparsely distributed cameras using a mobile camera

In sports science research, there are many topics that utilize the body motion of athletes extracted by motion capture system, since motion information is valuable data for improving an athlete’s skills. However, one of the unsolved challenges in motion capture is extraction of athletes’ motion information during the actual game or match, as placing markers on athletes is a challenge during game play. In this research, the authors propose a method for acquisition of motion information without attaching a marker, utilizing computer vision technology. In the proposed method, the three-dimensional world joint position of the athlete’s body can be acquired using just two cameras without any visual markers. Furthermore, the athlete’s three-dimensional joint position during game play can also be obtained without complicated preparations. Camera calibration that estimates the projective relationship between three-dimensional world and two-dimensional image spaces is one of the principal processes for the respective three-dimensional image processing, such as three-dimensional reconstruction and three-dimensional tracking. A strong-calibration method, which needs to set up landmarks with known three-dimensional positions, is a common technique. However, as the target space expands, landmark placement becomes increasingly complicated. Although a weak-calibration method does not need known landmarks, the estimation precision depends on the accuracy of the correspondence between image captures. When multiple cameras are arranged sparsely, sufficient detection of corresponding points is difficult. In this research, the authors propose a calibration method that bridges multiple sparsely distributed cameras using mobile camera images. Appropriate spacing was confirmed between the images through comparative experiments evaluating camera calibration accuracy by changing the number of bridging images. Furthermore, the proposed method was applied to multiple capturing experiments in a large-scale space to verify its robustness. As a relevant example, the proposed method was applied to the three-dimensional skeleton estimation of badminton players. Subsequently, a quantitative evaluation was conducted on camera calibration for the three-dimensional skeleton. The reprojection error of each part of the skeletons and standard deviations were approximately 2.72 and 0.81 mm, respectively, confirming that the proposed method was highly accurate when applied to camera calibration. Consequently, a quantitative evaluation was conducted on the proposed calibration method and a calibration method using the coordinates of eight manual points. In conclusion, the proposed method stabilizes calibration accuracy in the vertical direction of the world coordinate system.

Quality analysis using three-dimensional modelling and image processing techniques

PurposeThis paper aims to propose a system for defect detection in constructed elements that is able to indicate deformity positions. It also evaluates the defects in finishing materials of constructed building elements to support the subjective visual quality investigation of the aesthetics of an architectural work.Design/methodology/approachThis strategy depends on defect features analysis that evaluates the defect value in digital images using digital image processing methods. The research uses the three-dimensional (3D) modeling techniques and image processing algorithms to generate a system that is able to perform some of the monitoring activities by computers. Based on the collected site scans, a 3D model is created for the building. Then, several images can be exported from the 3D model to investigate a specific element. Different image denoizing techniques are compared such as mean filter, median filter, Wiener filter and Split–Bregman iterations. The most efficient technique is implemented in the system. Then, the following six different methods are used for image segmentation to separate the concerned object from the background; color segmentation, region growing segmentation, histogram segmentation, local standard deviation segmentation, adaptive threshold segmentation and mean-shift cluster segmentation.FindingsThe proposed system is able to detect the cracks and defected areas in finishing works and calculate the percentage of the defected area compared to the total captured area in the photo with high accuracy.Originality/valueThe proposed system increases the precision of decision-making by decreasing the contribution of human subjective judgment. Investigation of different finishing surfaces is applied to validate the proposed system.

Stereoscopic image quality assessment by analysing visual hierarchical structures and binocular effects

In the design of three-dimensional image processing systems, stereoscopic image quality assessment (SIQA) plays an indispensable role as a performance evaluator and a supervisor, yet the study upon which remains immature due to the complexity of the human visual system (HVS). In this study, a novel SIQA method is proposed by extracting quality-aware image features according to the properties of the hierarchical structure in the HVS. Especially, the interests of the primary and secondary visual cortex are taken into consideration, so that the image quality representation is constructed in a way both accurate and efficient. Moreover, influences caused by binocular effects including binocular rivalry and binocular visual discomfort are accounted to further improve the performance of the proposed method. The superiority of the proposed method is validated through experiments on public databases in comparison to state-of-the-art works in terms of accuracy and robustness.

A Survey on the Computation of Quaternions From Rotation Matrices

The parameterization of rotations is a central topic in many theoretical and applied fields such as rigid body mechanics, multibody dynamics, robotics, spacecraft attitude dynamics, navigation, three-dimensional image processing, and computer graphics. Nowadays, the main alternative to the use of rotation matrices, to represent rotations in ℝ3, is the use of Euler parameters arranged in quaternion form. Whereas the passage from a set of Euler parameters to the corresponding rotation matrix is unique and straightforward, the passage from a rotation matrix to its corresponding Euler parameters has been revealed to be somewhat tricky if numerical aspects are considered. Since the map from quaternions to 3 × 3 rotation matrices is a 2-to-1 covering map, this map cannot be smoothly inverted. As a consequence, it is erroneously assumed that all inversions should necessarily contain singularities that arise in the form of quotients where the divisor can be arbitrarily small. This misconception is herein clarified. This paper reviews the most representative methods available in the literature, including a comparative analysis of their computational costs and error performances. The presented analysis leads to the conclusion that Cayley's factorization, a little-known method used to compute the double quaternion representation of rotations in four dimensions from 4 × 4 rotation matrices, is the most robust method when particularized to three dimensions.

Analysis of Insole Geometry and Deformity by Using a Three-Dimensional Image Processing Technique: A Preliminary Study.

Accurate representation of the insole geometry is crucial for the development and performance evaluation of foot orthoses designed to redistribute plantar pressure, especially for diabetic patients. Considering the limitations in the type of equipment and space available in clinical practices, this study adopted a simple portable three-dimensional (3-D) desktop scanner to evaluate the 3-D geometry of an orthotic insole and the corresponding deformities after the insole has been worn. The shape of the insole structure along horizontal cross sections is defined with 3-D scanning and image processing. Accompanied by an in-shoe pressure measurement system, plantar pressure distribution in four foot regions (hallux, metatarsal heads, midfoot, and heel) is analyzed and evaluated for insole deformity. Insole deformities are quantified across the four foot regions. The hallux region tends to show the greatest changes in shape geometry (17%-50%) compared with the other foot regions after 2 months of insole wear. As a result of insole deformities, plantar peak pressures change considerably (-4.3% to +69.5%) during the course of treatment. Changes in shape geometry of the insoles could be objectively quantified with 3-D scanning techniques and image processing. This investigation finds that, in general, the design of orthotic insoles may not be adequate for diabetic individuals with similar foot problems. The drastic changes in the insole shape geometry and cross-sectional areas during orthotic treatment may reduce insole fit and conformity. An inadequate insole design may also affect plantar pressure reduction. The approach proposed herein, therefore, allows for objective quantification of insole shape geometry, which results in effective and optimal orthotic treatment.

Three-dimensional Image Processing Laboratory, Department of Media Science, Faculty of Information Science and Technology, Osaka Institute of Technology

Three-dimensional Image Processing Laboratory, Department of Media Science, Faculty of Information Science and Technology, Osaka Institute of Technology

Physical Bases of a ToF Camera–Based Optical Tracking System for Surgical Instruments

The physical principles of the operation of time-of-flight (ToF) cameras used for forming three-dimensional images are considered. Estimates of ToF camera characteristics are obtained using the example of a Kinect device. Algorithms for processing of three-dimensional images in a system of intraoperative navigation are described. Estimates of the accuracy of identifying the position of a surgical instrument are obtained.

Mass diffusivity determination of various building materials based on inverse analysis of relative humidity evolution at the back face of a sample

In this study, we use a novel method to determine the mass diffusion coefficients of hygroscopic materials. The experiment involves subjecting one face of the sample to relative humidity (RH) variations over time and measuring the RH at the back face. The imposed RH and temperature are measured during the experiment, and they are used as boundary conditions in a comprehensive computational code to address heat and mass transfer in porous media. This new method is utilized to characterize the following building materials: autoclave aerated concrete, plaster, poplar wood, pine wood, medium-density fiberboard and low-density fiberboard. This paper provides the details regarding the determination of the sorption isotherms of the selected materials that are required for the determination of mass diffusivity. The obtained electrical tortuosity values are compared with geometrical tortuosity values determined via microtomography and three-dimensional image processing. The agreement between the two tortuosity values is applicable only for porous media with narrow pore size distribution.

A videogrammetric system for measuring the full-field blade deformation of a heavy-duty helicopter's rotating rotor.

In this paper, a videogrammetric system, based on three-dimensional digital image processing and industrial close range photogrammetry technology, is proposed to solve the three-dimensional motion and deformation parameters of a rotating blade by identifying a speckle pattern. For the high aspect ratio and flexible rotor blade design often used in heavy-duty helicopters, there are extremely complex aerodynamic, dynamic, and coupling problems that require solutions to measure the full-field deformation of the rotating blade in the test condition of a rotor test tower. The key issues involved include a two-step calibration method using separate internal and external parameters for a large field of view, and a reliable estimation of the seed point method for a large deformation and weak correlation speckle images match. The system was developed and a simulation test was conducted on a rotor test tower. The results show that the proposed system is practicable to measure the surface displacement and motion parameters of a high-speed rotating rotor blade.

Correlation between increased orbital volume and enophthalmos and diplopia in patients with fractures of the orbital floor or the medial orbital wall

Fractures of the orbital floor and medial orbital wall (blowout fractures) are common midface injuries. Diagnostic methods and treatment options have improved over recent years, due to threedimensional image processing and the use of patient-specific implants. Nonetheless, the indications for orbital reconstructive surgery are still controversial. Previous authors have reported a linear correlation between post-traumatic increases in orbital volume and enophthalmos and diplopia. Post-traumatic increases in orbital volume are often considered to be predictive of long-term symptoms; therefore, it is commonly recommended that orbital volume increases be treated as an indication for early reconstructive surgery. However, the results of this study did not show any statistically significant long-term linear correlation between increased orbital volume and enophthalmos or diplopia, and the performance of orbital volume as a predictor of ocular symptoms was poor. Hence, we do not consider increased post-traumatic orbital volume to be particularly useful for predicting late enophthalmos or diplopia. However, a statistical correlation between fractures of the anterior and medial thirds of the orbital floor and double vision was found. As such, fractures of the middle and anterior third should be regarded as problematic, and surgical reconstruction should be considered in these cases.

Geometry based three-dimensional image processing method for electronic cluster eye

Geometry based three-dimensional image processing method for electronic cluster eye

Trueness and precision of digital impressions obtained using an intraoral scanner with different head size in the partially edentulous mandible

PurposeIt remains unclear whether digital impressions obtained using an intraoral scanner are sufficiently accurate for use in fabrication of removable partial dentures. We therefore compared the trueness and precision between conventional and digital impressions in the partially edentulous mandible. MethodsMandibular Kennedy Class I and III models with soft silicone simulated-mucosa placed on the residual edentulous ridge were used. The reference models were converted to standard triangulated language (STL) file format using an extraoral scanner. Digital impressions were obtained using an intraoral scanner with a large or small scanning head, and converted to STL files. For conventional impressions, pressure impressions of the reference models were made and working casts fabricated using modified dental stone; these were converted to STL file format using an extraoral scanner. Conversion to STL file format was performed 5 times for each method. Trueness and precision were evaluated by deviation analysis using three-dimensional image processing software. ResultsDigital impressions had superior trueness (54–108μm), but inferior precision (100–121μm) compared to conventional impressions (trueness 122–157μm, precision 52–119μm). The larger intraoral scanning head showed better trueness and precision than the smaller head, and on average required fewer scanned images of digital impressions than the smaller head (p<0.05). On the color map, the deviation distribution tended to differ between the conventional and digital impressions. ConclusionsDigital impressions are partially comparable to conventional impressions in terms of accuracy; the use of a larger scanning head may improve the accuracy for removable partial denture fabrication.

A finite element analysis of the effects of different skeletal protraction and expansion methods used in class III malocclusion treatment

This study aims to carry out an in-silico examination of the different skeletal advancement methods used in the treatment of maxillary retrusion patients. Computed tomography images of a young adolescent patient with maxillary retrusion were processed using three-dimensional medical image processing software to obtain a patient-specific model. Three different treatment scenarios were envisaged for the finite element analysis. In the first scenario, rapid maxillary expansion (RME) and face mask (FM); in the second, bone-assisted maxillary advancement and RME, and in the third, hybrid hyrax+mentoplate combination method were used. The hyrax screw was activated by 0.25mm in each model, with a force of 500g in the first scenario and 250g in the second and third scenario for each side. Von Mises stresses and the initial displacements were evaluated when different maxillary protraction methods were applied. We found that similar stress distributions were observed in the skull where the methods of RME/FM model and bone-assisted maxillary advancement were used. These stresses were higher than the hybrid hyrax+mentoplate combination method. When the displacement values were compared, anterior movement was found in the maxilla in the bone-supported model to include the middle face, while maxillary anterior movement of maxilla was detected on the Le Fort 1 level with the hybrid hyrax+mentoplate combination method. Dentoalveolar anterior movement was detected in the RME/FM model. Given the obtained stress distributions and displacement values, it has been observed that the bone-assisted maxillary advancement method provides more skeletal efficiency than the RME/FM and the hybrid hyrax+mentoplate combination methods.

New approaches of three-dimensional image processing applied to the study of lightweight mortars with EVA aggregates and piassava fibres

Civil construction is an alternative for the reuse of industrial discarded materials. The ethylene-vinyl acetate's residue as an aggregate, generates light materials with interesting thermal and acoustic properties. However, adding EVA reduces the material strength. To soften this effect, natural fibres like piassava can be added. This work proposes a methodology of three dimensional tomographic image analysis for the characterisation of lightweight mortars reinforced with piassava fibres. For this, several image features were calculated using different algorithms approaches focusing on the memory efficiency, the main handicap of three-dimensional image analysis. The methodology identified the EVA grains, the fibres and the pores, being insufficient collected information for the cracks identification. Also, it was possible to verify the fibre action as reinforcement. Regarding the algorithm performance analysis, the two-passage approaches were better, being the memory focused approach, the only one that can work with very big 3D images.

New approaches of three-dimensional image processing applied to the study of lightweight mortars with EVA aggregates and piassava fibres

Civil construction is an alternative for the reuse of industrial discarded materials. The ethylene-vinyl acetate's residue as an aggregate, generates light materials with interesting thermal and acoustic properties. However, adding EVA reduces the material strength. To soften this effect, natural fibres like piassava can be added. This work proposes a methodology of three dimensional tomographic image analysis for the characterisation of lightweight mortars reinforced with piassava fibres. For this, several image features were calculated using different algorithms approaches focusing on the memory efficiency, the main handicap of three-dimensional image analysis. The methodology identified the EVA grains, the fibres and the pores, being insufficient collected information for the cracks identification. Also, it was possible to verify the fibre action as reinforcement. Regarding the algorithm performance analysis, the two-passage approaches were better, being the memory focused approach, the only one that can work with very big 3D images.

Distal Femoral Rotation Correlates With Proximal Tibial Joint Line Obliquity: A Consideration for Kinematic Total Knee Arthroplasty

BackgroundWe hypothesized that there is a correlation between the distal femoral rotation and proximal tibial joint line obliquity in nonarthritic knees. This has significance for kinematic knee arthroplasty, in which the target knee alignment desired approximates the knee before disease. MethodsFifty computed tomography scans of nonarthritic knees were evaluated using three-dimensional image processing software. Four distal femoral rotational axes were determined in the axial plane: the transepicondylar axis (TEA), transcondylar axis (TCA), posterior condylar axis (PCA), and a line perpendicular to Whiteside's anterior-posterior axis. Then, angles were measured relative to the TEA. Tibial joint line obliquity was measured as the angle between the proximal tibial plane and a line perpendicular to the axis of the tibia. ResultsThere was a strong positive correlation between PCA-TEA and tibial joint line obliquity (r = 0.68, P < .001) as well as TCA-TEA and tibial joint line obliquity (r = 0.69, P < .001). In addition, the tibial joint line obliquity and TCA-TEA angles were similar, 3.7° ± 2.2° (mean ± standard deviation) and 3.5° ± 1.7°, respectively (mean difference, 0.2° ± 0.2°; P = .369). ConclusionBoth PCA-TEA and TCA-TEA strongly correlated with proximal tibial joint line obliquity indicating a relationship between distal femoral rotational geometry and proximal tibial inclination. These findings could imply that the native knee in flexion attempts to balance the collateral ligaments toward a rectangular flexion space. A higher tibial varus inclination is matched with a more internally rotated distal femur relative to the TEA.

Proximal tibial trabecular bone mineral density is related to pain in patients with osteoarthritis

BackgroundOur objective was to examine the relationships between proximal tibial trabecular (epiphyseal and metaphyseal) bone mineral density (BMD) and osteoarthritis (OA)-related pain in patients with severe knee OA.MethodsThe knee was scanned preoperatively using quantitative computed tomography (QCT) in 42 patients undergoing knee arthroplasty. OA severity was classified using radiographic Kellgren-Lawrence scoring and pain was measured using the pain subsection of the Western Ontario and McMaster Universities Arthritis Index (WOMAC). We used three-dimensional image processing techniques to assess tibial epiphyseal trabecular BMD between the epiphyseal line and 7.5 mm from the subchondral surface and tibial metaphyseal trabecular BMD 10 mm distal from the epiphyseal line. Regional analysis included the total epiphyseal and metaphyseal region, and the medial and lateral epiphyseal compartments. The association between total WOMAC pain scores and BMD measurements was assessed using hierarchical multiple regression with age, sex, and body mass index (BMI) as covariates. Statistical significance was set at p < 0.05.ResultsTotal WOMAC pain was associated with total epiphyseal BMD adjusted for age, sex, and BMI (p = 0.013) and total metaphyseal BMD (p = 0.017). Regionally, total WOMAC pain was associated with medial epiphyseal BMD adjusted for age, sex, and BMI (p = 0.006).ConclusionThese findings suggest that low proximal tibial trabecular BMD may have a role in OA-related pain pathogenesis.