3D Color Research Articles

V72 - Colored perfusion areas-based 3D virtual models: The Rainbow Kidney as a new tool to optimize the clamping strategy during robot-assisted partial nephrectomy

V72 - Colored perfusion areas-based 3D virtual models: The Rainbow Kidney as a new tool to optimize the clamping strategy during robot-assisted partial nephrectomy

3D-RPP: a novel 3D vision-based Pose Perception Approach for Industrial Robots

Enhanced by artificial intelligence, industrial robots are becoming more powerful, gaining a large variety of applications in intelligent factories. Pose perception, the aim of which is to obtain the joint coordinates of the robot in the camera coordinate system, has been proposed as a promising technology for multi-robot intelligent interaction. A large number of efforts have been made on studying robot pose perception. However, most of existing studies estimate the position of robot joints in 3D space by just using 2D color images, and perform pose perception by estimating the position of joint key points in the image, which could become infeasible in scenarios with various camera views and background environments. To address the issue, considering the information about the robot itself as a prior knowledge, we propose a novel approach for robot pose perception, named 3D-RPP. We adopt a 3D visual point cloud to estimate the rigid transformation of the camera coordinate system with respect to the robot base coordinate system, which effectively improves the accuracy of the obtained robot joint position in the camera coordinate system. We conduct extensive experiments on ROKAE xMate3 robot to investigate the performance of 3D-RPP, and the experimental results show that 3D-RPP could solve the pose perception problem well.

Utility of Hepatic 2D Shear-Wave Elastography in Monitoring Response to Image-Guided Intervention in Children With Chronic Budd-Chiari Syndrome: A Prospective Study.

BACKGROUND. Image-guided interventions for Budd-Chiari syndrome (BCS) reduce hepatic congestion, thereby reducing liver stiffness. Liver stiffness measurement (LSM) by means of ultrasound may provide a noninvasive marker for assessing treatment response. OBJECTIVE. The purpose of this study was to assess, with attention to changes in LSMs in patients with disease recurrence, the utility of 2D shear-wave elastography (SWE) for monitoring response to image-guided intervention in children with BCS. METHODS. This prospective study included children with chronic BCS and planned image-guided intervention. Color Doppler ultrasound (CDUS) and 2D SWE were performed at baseline; 24 hours, 1 month, and 3 months after intervention; and every 3 months thereafter or when recurrence was clinically suspected. Eighteen children underwent liver biopsy at intervention for fibrosis staging according to the Metavir criteria. Disease recurrence was diagnosed with CDUS. Statistical evaluation was performed by means of nonparametric tests. RESULTS. A total of 32 children (28 boys, four girls; mean age, 9 years; range, 3-14 years) were included. The median LSM at baseline was 43.7 (interquartile range [IQR], 33.0-65.4) kPa, at 24 hours was 22.5 (IQR, 16.8-32.0) kPa, at 1 month was 18.7 (IQR, 14.2-32.0) kPa, and at 3 months was 16.7 (IQR, 11.5-22.5) kPa (p = .001 for all postintervention time points vs baseline). Nine (28.1%) patients had a recurrence at a mean of 4 months after intervention. In one patient with recurrence, LSM was higher at 24 hours (52.3 kPa) than at baseline (44.2 kPa). In the other eight patients with recurrence, LSM was increased at recurrence compared with the prior postintervention LSM (median absolute increase, 11.0 [IQR, 6.1-24.4] kPa). Fibrosis stage was not significantly correlated with baseline LSM (r = 0.11 [95% CI, -0.37 to 0.54]; p = .51) or LSM 24 hours after intervention (r = 0.39 [95% CI, -0.11, 0.73]; p = .11). CONCLUSION. LSMs decreased significantly after image-guided intervention for chronic BCS in children, exhibiting a maximal decrease 24 hours after intervention. Disease recurrence was typically associated with an increase in LSM compared with the patient's prior measurement. CLINICAL IMPACT. LSM obtained with 2D SWE may serve as a useful quantitative adjunct to CDUS in monitoring children with chronic BCS for disease recurrence after percutaneous interventional treatment.

Dynamic three‐dimensional virtual environment to improve learning of anatomical structures

Increasing number of medical students and limited availability of cadavers have led to a reduction in anatomy teaching through human cadaveric dissection. These changes triggered the emergence of innovative teaching and learning strategies in order to maximize students learning of anatomy. An alternative approach to traditional dissection was presented in an effort to improve content delivery and student satisfaction. The objective of this study is to acquire three-dimensional (3D) anatomical data using structured-light surface scanning to create a dynamic four-dimensional (4D) dissection tool of four regions: neck, male inguinal and femoral areas, female perineum, and brachial plexus. At each dissection step, identified anatomical structures were scanned using a 3D surface scanner (Artec Spider™). Resulting 3D color meshes were overlaid to create a 4D (3D+time) environment. An educational interface was created for neck dissection. Its implementation in the visualization platform allowed 4D virtual dissection by navigating from surface to deep layers and vice versa. A group of 28 second-year medical students and 17 first-year surgery residents completed a satisfaction survey. A majority of medical students (96.4%) and 100% of surgery residents said that they would recommend this tool to their colleagues. According to surgery residents, the main elements of this virtual tool were the realistic high-quality of 3D acquisitions and possibility to focus on each anatomical structure. As for medical students, major elements were the interactivity and entertainment aspect, precision, and accuracy of anatomical structures. This approach proves that innovative solutions to anatomy education can be found to help to maintain critical content and student satisfaction in anatomy curriculum.

An Exploration into Color Reproduction for Inkjet FDM Color 3D Printing

Advancing in inkjet fused deposition modeling (FDM) color 3D printing enables to create dedicated aesthetical appeal. However, the complete fabrication of a target color remains limited due to the unusual mismatch in 3D color management systems. In particular, the 3D aspect that makes the 3D color systems different from standard 2D printing, such as ink and substrate characteristics, viewing conditions, and base materials. Therefore, to the best of our knowledge, there is no suitable established method that supports color reproduction for inkjet FDM color 3D printing. In this paper, we analyze the color profile of an inkjet FDM color 3D printer to obtain a color model that could bridge the gap between a digital design (as an input) and the actual 3D printed results (as an output). We then created the color model by reproducing each color mapped to every possible color pair to determine the closest color between the target and printing colors on the basis of the color difference value, which can be rendered in lieu of the original printing colors. We verify our proposed color model by printing the mapped color and conduct a color measurement to compare it with the target colors. From the experimental results, we showed that our mapped colors can represent those desired by the user with an 80% success rate, which can be matched through controlled conditions.

Ratiometric 4Pi single-molecule localization with optimal resolution and color assignment.

4Pi single-molecule localization microscopy (4Pi-SMLM) with two opposing objectives achieves sub-10 nm isotropic 3D resolution when as few as 250 photons are collected by each objective. Here, we develop a new ratiometric multi-color imaging strategy for 4Pi-SMLM that employs the intrinsic multi-phase interference intensity without increasing the complexity of the system and achieves both optimal 3D resolution and color separation. By partially linking the photon parameters between channels with an interference difference of π during global fitting of the multi-channel 4Pi single-molecule data, we show via simulated data that the loss of localization precision is minimal compared with the theoretical minimum uncertainty, the Cramer-Rao lower bound.

Portable solution for high-resolution 3D and color texture on-site digitization of cultural heritage objects

A peculiar characteristic of cultural heritage objects is their uniqueness. This results in an enormous importance for their preservation against aging, accidents, destruction etc. Although not replacing physical preservation, one way is the digitization of the objects in their current state by modern scanning technologies. This research describes a new method to combine 3D shape and color texture data acquired without contact to achieve high-resolution 3D representations. The method was basis of a portable 3D digitization system. The portable character allows its application on-site, which is essential for sensitive and non-transportable objects. A structured-light 3D sensor and a photo camera are used to capture the object from various overlapping perspectives. Then, the 3D shape and photographic data are processed and merged into a complete textured 3D model. Resolution and accuracy of the final model are in the range of 0.1 mm. Beyond preservation, the models can be used to make museum objects digitally available for experts or visitors worldwide e.g. in the form of online databases or virtual museums. A first utilization of the presented technology was realized with historic globes, especially with a Schöner globe dating from 1515 as highlight. The used method can be extended beyond RGB texture acquisition using multi-/hyperspectral sensors leading to an increased information content about the objects.

Blind Light Field Image Quality Assessment with Tensor Color Domain and 3d Shearlet Transform

Blind Light Field Image Quality Assessment with Tensor Color Domain and 3d Shearlet Transform

Influence of Different Fabrication Techniques on the Accuracy of Radiographic Scan Templates in Cases of Full-Arch Computer-Guided Implant Placement: An In Vitro Study.

To evaluate the influence of using different fabrication techniques, including intraoral scans, CBCT scans of patients' existing dentures, or denture duplicates, on the accuracy of radiographic scan templates. The influence of selecting different segmentation threshold values during reconstruction of CBCT data was also evaluated. A reference model was obtained by scanning five pairs of maxillary and mandibular acrylic complete dentures using a desktop laboratory laser scanner (DWOS 7Series, Dental Wings). Test scans were obtained from intraoral scans of dentures, CBCT scans of dentures and denture duplicates reconstructed at different grayscale segmentation thresholds, and a laboratory scan of denture duplicates. The resultant STL scan files were imported to an open source and cloud storage software (Medit Link) for the accuracy measurements by calculating root mean square estimate (RMSE) between reference and test scans. Collected data were then analyzed. Qualitative analysis was also performed using 3D color maps. The lowest RMSE (352.7) was found with intraoral denture scans. The highest RMSE (1,336.3) was found with the CBCT scans of the denture duplicates at segmentation threshold of -700 grayscale level. Qualitative analysis revealed that the intraoral denture scans exhibited the most homogenous deviation pattern relative to reference lab scans. Within the limitations of this study, the intraoral scans of the patients' existing dentures resulted in the fabrication of the most accurate radiographic scan templates. The improved accuracy of scan templates fabricated using the intraoral scanners can eliminate the possible laboratory errors associated with the conventional technical procedures as well as reduce the inaccuracies resulting from the image processing and segmentation of CBCT data.

VR Color Picker: Three-Dimensional Color Selection Interfaces

In this paper, we propose a 3D color picker for virtual reality (VR) systems. Using the proposed color picker, the RGB and HSV color spaces are displayed in 3D shape, and a color can be selected through a one-step interaction by pointing at a location inside the color space with a 3D pointing device. This process is very simple compared with the multistep color selection interactions required for existing VR color pickers. Since the interior of the color space is not visible, we also propose three types of user interfaces that show the interior of the color space. These interfaces either cut out a portion of the color space, show cross-sections of the color space, or show discrete samples placed in the color space. We conducted user experiments on the color selection time, color selection accuracy, and usability and proved the usefulness and effectiveness of the proposed VR color picker.

Design and Implementation of Special-Purpose Computer for Incoherent Digital Holography

We designed and implemented a special-purpose computer for incoherent color digital holography for application in three-dimensional (3D) microscopy. We focused on multiwavelength-multiplexed phase-shifting incoherent color digital holography as a method for acquiring 3D color-reconstructed images. This method records holograms faster than conventional temporal division methods. However, the reconstruction calculation of this method requires a significant amount of time, similar to the conventional method. Therefore, we designed a circuit for high-speed image reconstruction. We designed a Fresnel diffraction circuit that requires repetitive calculations to obtain a 3D color image but incurs a high calculation cost. We implemented the circuit on a field-programmable gate array (FPGA) and successfully calculated reconstructed images that were of the same quality as those calculated by the central processing unit (CPU) of a personal computer (PC). The calculation time was approximately 2.6 times faster than that of the CPU.

Carbon Dots from Turnip Juice: Synthesis, Characterization and Investigation of pH-Dependent Optical Properties

In this study, carbon dots (CDs) were synthesized using a simple one-pot hydrothermal method by using turnip juice as carbon source. The water-soluble nontoxic carbon dots were obtained after reaction. The structural and optical properties of as synthesized CDs were elucidated by X-ray diffraction (XRD), Raman, Fourier Transmission Infrared (FTIR), UV–Vis absorption and Photoluminescence (PL) spectroscopy. A contour plot of the excitation dependent PL spectra of the turnip juice derived CDs and PL emission spectra in 3D color map were plotted. The maximum PL emission was found at 434 nm when excited at 364. The pH dependent luminescence properties of the CDs were investigated from pH 2-12 range in phosphate buffer solution (PBS). The resulting CDs can be evaluated in a variety of application areas, from anti-counterfeiting to bioimaging.

Quantum error correction with the color-Gottesman-Kitaev-Preskill code

The Gottesman-Kitaev-Preskill (GKP) code is an important type of bosonic quantum error-correcting code. Since the GKP code only protects against small shift errors in $\hat{p}$ and $\hat{q}$ quadratures, it is necessary to concatenate the GKP code with a stabilizer code for the larger error correction. In this paper, we consider the concatenation of the single-mode GKP code with the two-dimension (2D) color code (color-GKP code) on the square-octagon lattice. We use the Steane type scheme with a maximum-likelihood estimation (ME-Steane scheme) for GKP error correction and show its advantage for the concatenation. In our main work, the minimum-weight perfect matching (MWPM) algorithm is applied to decode the color-GKP code. Complemented with the continuous-variable information from the GKP code, the threshold of 2D color code is improved. If only data GKP qubits are noisy, the threshold reaches $\sigma\approx 0.59$ $(\bar{p}\approx13.3\%)$ compared with $\bar{p}=10.2\%$ of the normal 2D color code. If measurements are also noisy, we introduce the generalized Restriction Decoder on the three-dimension space-time graph for decoding. The threshold reaches $\sigma\approx 0.46$ when measurements in the GKP error correction are noiseless, and $\sigma\approx 0.24$ when all measurements are noisy. Lastly, the good performance of the generalized Restriction Decoder is also shown on the normal 2D color code giving the threshold at $3.1\%$ under the phenomenological error model.

Low concentration Phloxine B staining for high chemical contrast, nonlinear microscope mosaic imaging of skin alterations in pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is an autosomal recessive metabolic disorder characterized by ectopic mineralization of soft connective tissue. Histopathology findings include fragmented, mineralized elastic fibers and calcium deposits in the mid-dermis. Nonlinear microscopy (NLM) can be used for visualization of these histopathological alterations of the mid-dermis in PXE-affected skin sections. Upon introducing a normalized 3D color vector representation of emission spectra of three of the main tissue components (collagen, elastin and calcification) we found that due to their broad, overlapping emission spectra, spectral separation of emission from elastin and calcification is practically impossible in fresh-frozen or unstained, deparaffinized PXE sections. However, we found that the application of a low concentration Phloxine B staining after the deparaffinization process creates an imaging contrast for these two tissue components, which enables spectral decomposition of their fluorescence images. The obtained concentration maps for calcium deposits can be well suited for the determination of illness severity by quantitative analysis.

A Legorization method based on 3D color printing trajectory

In this paper, a Legorization method which can reconstruct LEGO model with complex internal and external structures from 3D color printing trajectory is proposed. Different from voxelization methods, by combining advanced adaptive slicing algorithm with building “high-resolution” regions with thin plates, the reconstruction accuracy of initial LEGO units can be guaranteed. Furthermore, the tree structure is employed for automatically generating support structures which can be converted into LEGO support structures. By adopting split assembly appropriately and implementing combination of these parts accurately, the reducing supporting structures can be further simplified. In order to optimize the Legorization scheme, a machine learning method is used to guarantee the quality and efficiency of the reconstruction work. Complex LEGO models are provided to demonstrate the effectiveness of the proposed method.

Automatic Unfolding of CityGML Buildings to Paper Models

3D city models are mainly viewed on computer screens, but many municipalities also use 3D printing to make urban planning tangible. Since 3D color printing is still comparatively expensive and the colors often fade over time, many of these models are monochrome. Here, color textured paper models offer an inexpensive and under-appreciated alternative. In this paper, a greedy algorithm adapted to CityGML building models is presented, which creates print templates for such paper models. These 2D layouts consist of cut edges and fold edges that bound polygons of a building. The polygons can be textured or left blank depending on the existence of CityGML textures. Glue tabs are attached to cut edges. In addition to the haptic 3D visualization, the quality of the 3D models can sometimes be better assessed on the basis of the print templates than from a perspective projection. The unfolding procedure was applied to parts of the freely available CityGML model of Berlin as well as to parts of models of the cities of Dortmund and Krefeld.

Accurate and robust feature description and dense point-wise matching based on feature fusion for endoscopic images.

Despite the rapid technical advancement of augmented reality (AR) and mixed reality (MR) in minimally invasive surgery (MIS) in recent years, monocular-based 2D/3D reconstruction still remains technically challenging in AR/MR guided surgery navigation nowadays. In principle, soft tissue surface is smooth and watery with sparse texture, specular reflection, and frequent deformation. As a result, we frequently obtain only sparse feature points that give rise to incorrect matching results with conventional image processing methods. To ameliorate, in this paper we enunciate an accurate and robust description and matching method for dense feature points in endoscopic videos. Our new method first extracts contours of the low-rank image sequences based on the adaptive robust principal component analysis (RPCA) decomposition. Then we propose a multi-scale dense geometric feature description approach, which simultaneously extracts dense feature descriptors of the contours in the original Euclidean coordinate space, the accompanying 3D color coordinate space, and the derived curvature-gradient coordinate space. Finally, we devise a new algorithm for both global and local point-wise matching based on feature fusion. For global matching, we employ the fast Fourier transform (FFT) to reduce the dimension of the dense feature descriptors. For local feature point matching, in order to enhance the robustness and accuracy of the matching, we cluster multiple contour points to form "super-point" based on dense feature descriptors and their spatio-temporal continuity. The comprehensive experimental results confirm that our novel approach can overcome the highlight influence, and robustly describe contours from image sequences of soft tissue surfaces. Compared with the state-of-the-art feature point description and matching methods, our analysis framework shows the key advantages of both robustness and accuracy in dense point-wise matching, even when the severe soft tissue deformation occurs. Our new approach is expected to have high potential in 2D/3D reconstruction in endoscopy.

Colour volumetric display based on holographic-laser-excited graphics using drawing space separation

A volumetric display generates a graphics that can be viewed from 360^{circ } by representing the 3D information of an object as voxels in physical space. However, the natural properties of physical objects, such as 3D information and colors, and the seamless relationships between graphics and humans make it difficult to implement such displays. Here, we introduce a novel system that combines the spatial generation of femtosecond-laser-excited emission points using computer-generated holograms and beam scanning with the drawing space separation method. We demonstrate the drawing of volumetric graphics that can be color-expressed in voxel units in the air. This system enables the drawing of volumetric graphics in the air, accurate color representations, and robust graphics that are not destroyed by contact with users or objects. It also lays the foundation for the implementation of future volumetric displays.

Tunable photo-patterning of organic color-centers

Organic color-centers (OCCs) in single-walled carbon nanotubes (SWCNTs) have been intensively investigated for quantum technologies, bio- and chemical sensing, bioimaging. The precise localization of OCCs at a scalable manner will bring about a revolution into next generation optoelectronics, which, however, remains a great challenge till now. Here, a scalable, low cost and universal photo-patterning strategy is developed to implant OCCs at desired locations on (6,5)-chirality SWCNT films by combining optically active diazonium chemistry and micro-contact printing methods. Notably, the patterns can be tunable by changing the solvents used for the patterning chemistry, affording control over the weight of diazonium salts at different regions. A systematic investigation reveals that the solvent properties (polarity and vapor pressure), the volume and concentration of ink used, the patterning methods, and the concentration of MeODz all contribute to the tunable patterning. This spatial accurate and solvent tunable photo-patterning technique is simple, scalable, and amenable to the integration of other color center chemistries and 2D transition metal dichalcogenides for the next-generation chip-integrated nanoelectronics and optoelectronics with high device uniformity and manipulability at molecular level.

Abstract 12610: Larger Papillary Muscles and Thicker Chords Were Associated With Post-Operative Left Atrioventricular Valve Regurgitation in Partial AVSD, a Quantitative Three-Dimensional Echocardiography Study

Background: Up to 15% of patients with partial Atrioventricular Septal Defects ( p AVSD) require re-repair of the Left AtrioVentricular Valve (LAVV), with 30% having significant regurgitation. Previous qualitative studies suggest abnormalities in papillary muscles, shortened chordae and thick chords as features associated with LAVVR. We aim to quantitatively assess the sub valvar apparatus in pAVSD using three-Dimensional Echocardiography (3DE) for its association with LAVVR. Hypothesis: We hypothesize that larger papillary muscle and chordal thickness in patients with p AVSD is associated with post-operative LAVVR. Methods: This is a prospective study between 2006 and 2018, of pAVSD aged 0-18 years. All underwent 3DE under sedation using X7-2 probe on a Philips iE33 ultrasound system. Utilizing offline QLAB multi-planar reconstruction (v.10.8.5) we measured anterolateral (APM) and posteromedial papillary (PPM) muscle length; cross sectional area and circumference; chordal length and thickness in mid systole. We measured post-operative vena contracta and LAVV diameter in Apical 4 chamber using 2D color Doppler. Cohort was divided into patients with significant post-operative LAVVR vs. controls based on LAVV vena contracta/LAVV annulus ratio cut off >0.25 (greatest one-third of cohort), LAVVR (n=22) and Controls (n=44). All variables are indexed to Body Surface Area, expressed as median [interquartile range] or mean (standard deviation). Results: LAVVR group were younger at initial surgery, had larger papillary muscles and thicker chords. Table 1 summarizes the variables for Control and LAVVR. Eighteen patients had LAVV re-repair, 14 (63%) were in LAVVR group and 4 (9%) in Controls. Median follow up was 1.5 years. Median time to re-repair was 1.3 years. Conclusion: p AVSD patients with a greater risk of post-operative LAVVR and subsequently re-repair were younger at first repair and had larger papillary muscles length, circumference and thicker chords.