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[IEEE 2017 International Conference on 3D Vision (3DV) - Qingdao (2017.10.10-2017.10.12)] 2017 International Conference on 3D Vision (3DV) - Towards Accurate Marker-Less Human Shape and Pose Estimation over Time
摘要： Existing markerless motion capture methods often assume known backgrounds, static cameras, and sequence specific motion priors, limiting their application scenarios. Here we present a fully automatic method that, given multi-view videos, estimates 3D human pose and body shape. We take the recently proposed SMPLify method [12] as the base method and extend it in several ways. First we fit a 3D human body model to 2D features detected in multi-view images. Second, we use a CNN method to segment the person in each image and fit the 3D body model to the contours, further improving accuracy. Third we utilize a generic and robust DCT temporal prior to handle the left and right side swapping issue sometimes introduced by the 2D pose estimator. Validation on standard benchmarks shows our results are comparable to the state of the art and also provide a realistic 3D shape avatar. We also demonstrate accurate results on HumanEva and on challenging monocular sequences of dancing from YouTube.
关键词： multi-view,3d reconstruction,body model,marker-less,shape and pose estimation
更新于2025-09-10 09:29:36
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Insights into innovative breast imaging techniques
摘要： Our work as radiologists is inextricably entwined with technology. Without William Roentgen's discovery of X-rays and systematic study of their utility, our medical subspecialty would not exist in its current form. As imaging technology has grown, so, too, has the field of radiology. Scientific innovation has driven technological advances and vice versa, a wondrous circle that provides the tools for more robust medical imaging, better understanding of human physiology and pathophysiology, and better patient care. As radiologists, we are uniquely qualified not only to use the technology handed to us, but to help refine, improve, and make it better suited to our clinical needs as well as those of our medical and surgical colleagues. We can even help to drive new development and push technology in the most clinically useful direction. In order to do this, we must be experts in our tools. We must understand the technology that we use and know its strengths and weaknesses. We must see its limitations in order to derive the most out of it and practice responsibly.
关键词： precision medicine,tomosynthesis,biopsy marker clips,breast imaging,radiogenomics
更新于2025-09-10 09:29:36
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Visualized Detection of Polyelectrolytes via 1D Photonic Crystals
摘要： The organic/inorganic hybrid 1D photonic crystal is applied for visible and label-free detection of charged substances. Exposure to aqueous solutions of various polyelectrolytes alters the swelling ratios of quaternized polymer layers due to the ionic interaction. Visible detection is thus attained along with a shift of the photonic stop band. Especially, by virtue of the diverse degrees and speeds of the shift, polyanions with different concentrations and molecular weights can be differentiated. Likewise, natural polyelectrolytes, such as proteins, have different solution pH values and isoelectric points. Thus, different charged properties yield three kinds of proteins that can be distinguished by the device via reflectance spectra. It is worth noting that biomarkers of illness with different concentrations can also be detected via the naked eye, without any labels. Fortunately, the detection sensitivity basically satisfies the usage requirement. Due to the convenience, flexibility, low power consumption and visibility, the label-free sensor is suitable for daily life.
关键词： one-dimensional photonic crystals,polyelectrolyte,isoelectric point,visualized detection,cancer marker
更新于2025-09-10 09:29:36
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[IEEE 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - Bremen, Germany (2018.10.25-2018.10.26)] 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - Optical Camera Communication for Active Marker Identification in Camera-based Positioning Systems
摘要： Outside-in camera-based localization systems determine the position of mobile objects (with markers attached to them) by observing a tracking area with multiple camera anchors. Up to now the identi?cation of the objects in the camera images only works for close objects (with passive 3-dimensional marker constellations) or when tracking gaps or a slow identi?cation are acceptable (with an active LED that blinks a unique identi?cation code). We present a novel Optical Camera Communication method whose LEDs are never switched off completely to allow continuous tracking. We encode bits with variations of light intensity and show how an outside-in optical localization system can reliably identify the markers within a few frames. The identi?cation works with a bit error ratio of 7.5 · 10?5. It works for moving markers (with speeds of at least up to 4 m s ), for distant markers (with distances of at least up to 44 m), for multiple markers, and under moderate ambient infrared light.
关键词： Localization Systems,Active Marker Identification,Optical Camera Communication,Camera-based Positioning Systems
更新于2025-09-09 09:28:46
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Direct Imaging of Photo-Switching Molecular Conformations Using Individual Metal Atom Markers
摘要： Photo-switching behavior of individual organic molecules was imaged by annular dark-field scanning transmission electron microscopy (ADF-STEM) using a highly electron beam transparent graphene support. Photo-switching azobenzene derivatives with ligands at each ends containing single transition metal atoms (Pt) were designed (Pt-complex), and the distance between the strong ADF-STEM contrast from the two Pt atoms in each Pt-complex is used to track molecular length changes. UV irradiation was used to induce photo-switching of the Pt complex on graphene, and we show that the measured Pt-Pt distances within isolated molecules decreases from ~2.1 nm to ~1.4 nm, indicative of a trans-to-cis isomerization. Light illumination of the Pt-complex on the graphene support also caused their diffusion out from initial clusters to the surrounding area of graphene, indicating that the light-activated mobilization overcomes the inter-molecular van der Waals interactions. This approach shows how individual isolated heavy metal atoms can be included as markers into complex molecules to track their structural changes using ADF-STEM on graphene supports, providing an effective method to study a diverse range of complex organic materials at the single molecule level.
关键词： annular dark-field scanning transmission electron microscopy,photo-switch,direct imaging,graphene support,heavy atom marker,azobenzene
更新于2025-09-09 09:28:46
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Quantification of image artifacts from navigation markers in dynamic guided implant surgery and the effect on registration performance in different clinical scenarios
摘要： Purpose: Different navigation markers in dynamic guided implant surgery could cause different degrees of artifacts, which would affect the accuracy and efficiency of the implant navigation system. This study aimed to quantify artifacts caused by navigation markers made of different materials and to evaluate their effects on registration accuracy under various oral conditions. Materials and Methods: Four U-shaped tubes with different navigation markers (440c stainless steel, silicon nitride, zirconium oxide, and aluminium oxide) were produced by three-dimensional printing. Four kinds of maxillary plaster models were prepared to stimulate four tooth crown conditions. U-shaped tubes combined with different tooth models were scanned using cone beam computed tomography (CBCT). The size of artifacts from different navigation markers and registration rate were measured. Abrasion performance of navigation markers was evaluated by scanning electron microscopy (SEM) images. Results: Aluminium oxide navigation markers showed the fewest artifacts. Silicon nitride markers caused fewer artifacts than zirconium oxide and 440c stainless steel ones (P < .05) and had the best registration performance under all tooth crown conditions with the lowest volume of abrasion. Registration data suggested aluminium oxide worked badly under artificial crown and natural tooth conditions for its lower radiopacity, and zirconium oxide worked undesirably in edentulous conditions. 440c stainless steel was worst in all dental conditions. Conclusion: Navigation markers made of silicon nitride have the best overall performance and perform the best in registration under all circumstances owing to less artifact generation, better radiopacity, and desirable abrasion resistance. Silicon nitride can be regarded as an ideal material, including but not limited to oral implant navigator-guided surgery.
关键词： Dental implants,Navigation marker,Cone-Beam Computed Tomography,Artefacts,Dynamic guided,Registration
更新于2025-09-09 09:28:46
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Electrochromic effect of indium tin oxide in lithium iron phosphate battery cathodes for state of charge determination
摘要： In this paper, we discuss the origin of an optical effect in lithium iron phosphate (LFP) battery cathodes, which depends on the electrical charge transferred into the battery. Utilizing indium tin oxide (ITO) as an electrode additive, we were able to observe a change in reflectivity of the cathode during charging and discharging with lithiation and delithiation being clearly visible in the form of lithiation fronts. Further investigations using in situ video microscopy and in situ Raman spectroscopy on test cells with an optical window indicates that ITO additionally acts as an electrochromic marker within the LFP cathode. This enhances the optical effect due to local potentials around the lithiation fronts, which enables the voltage-dependent reflectivity of the ITO to be visible in the LFP cathode. Structural analysis with scanning electron microscopy (SEM) and X-ray crystallography (XRD) are presented as well. The observed effect allows for novel battery research methods and for a possible commercial application as a sensor for state of charge (SOC) estimation similar to the optical fiber approach reported by Ghannoum et al. for a graphite anode.
关键词： lithium ion batteries,battery state determination,lithium iron phosphate,raman spectroscopy,indium tin oxide,electrochromic marker,video microscopy,state of charge
更新于2025-09-04 15:30:14