Object Plane Research Articles

Uniform, Universal, Shadowless TIRF Microscopy Via Annular Fiber Bundle

Total internal reflection fluorescence (TIRF) illumination is a popular excitation method in fluorescence microscopy. TIRF illumination is generated when the excitation beam strikes the glass/water interface of the sample at an angle greater than the critical angle, creating an evanescent excitation field with a shallow penetration depth that is well-suited to studying single-molecules and surface features of a biological sample with a high signal-to-background ratio. TIRF is typically achieved by focusing the excitation laser beam to the outermost edge of the back focal plane (BFP) of the imaging objective; however, this approach suffers from imaging artifacts such as interference fringes from the coherent excitation source and shadowing artifacts caused by the unidirectional light and scattering objects in cells.

HARVEST: High-Resolution Haptic Vest and Fingertip Sensing Glove That Transfers Tactile Sensation of Fingers to the Back

Human fingertips are densely populated with tactile receptors and are hence incredibly sensitive. However, wearing gloves on the fingers drastically reduces the tactile information available to the fingertips, such as the texture and shape of the object, and makes it difficult to perform dexterous work. As a solution, in this study, we developed a high-resolution haptic vest that transfers the tactile sensation of the fingertips to the back. The haptic vest contains 80 voice-coil type vibrators which are located at each of the two discrimination thresholds on the back and can be driven independently. The tactile sensation of the fingertips is transferred to the back using the developed haptic vest in combination with a sensing glove that can detect the pressure distribution on the finger skin at up to 100 points. Different experiments were conducted to validate the performance of the proposed haptic vest and sensing gloves. The use of the haptic vest and the sensing glove enabled the user to perceive the shape of a planar object more accurately when compared to the case where the user wore only the glove.

Bidirectional Human–Robot Bimanual Handover of Big Planar Object With Vertical Posture

Object handover is one of the basic abilities for the robot to interact with the human. Most of the previous works only focus on the limited handover scenarios where the robot uses one hand to give small objects to the human. In this article, we design a bidirectional bimanual handover system that enables the robot to both give and receive the big planar object with vertical grasp posture. In addition to the basic object handover function, the designed handover system also integrates a position adjustment mechanism to improve the human experience. According to different task states, the system is divided into four modes. In each mode, the robot performs a subtask and switches to the next mode at an appropriate time. We propose a two-finger grip force controller and a dual-arm admittance NN controller to control the robot to generate actual motions. By applying specific locating, trajectory planning, and signal identifying methods, we implement the designed handover system on a Baxter robot. The system is tested on two wooden plates with different widths, thicknesses, and weights. The results show that the robot can perform the handover task safely and effectively with the designed handover system. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —This article aims to solve the limitation that the robot can only hand over small objects with one hand in the human–robot handover systems. In daily life, especially in carrying tasks, many objects, such as windows, wooden boards, and big frames, may also be handed over to each other. These objects can be classified as big planar objects. To enable the robot to hand over this kind of object with the human, we design a bidirectional bimanual human–robot handover system. The designed system has three main functions. First, the robot can receive the big planar object from the human and hold the object safely with two hands, which is impossible in a single-hand handover system because the weight and size of the object are large. Then, the robot can help the human hold the object or transport it to other places. Second, the robot can adjust the object handover position according to the human’s intentions while holding the object. Because the size of objects and the height of humans may different, or some tasks require that the human position be higher or lower than the robot, the current object holding position may be hard for the current human operator to take over the object. With this function, the human can move the object to an appropriate position and then take it comfortably. Third, the robot releases the object only when it gets a clear signal. Before that, the robot always grasps the object safely, and the human can freely adjust his posture. With the designed handover system, the robot can cooperate with the human to complete more tasks indoors or in factories.

Entropy feature and peak-means clustering based slowly moving object detection in head and shoulder video sequences

With the increase in demand for video conferencing and IOT applications, efficient video coding standards are necessary. The performance of MPEG-4 coding scheme depends on the efficiency of the video object plane (VOP) generation methods. In head and shoulder video, such as news reading, video conferencing video sequences, the object has a very little movement in between two consecutive frames. Therefore, traditional segmentation methods could not extract the complete VOP efficiently. In this paper, we propose an efficient spatiotemporal segmentation method to extract the moving object for the generation of VOP in head and shoulder video sequences. First, a motion map of the object at each frame is generated based on the entropy of the temporal change of each pixel. Secondly, each frame is spatially segmented based on peak-means clustering approach. Finally, both motion map and spatial segmentation information are fused to extract the complete shape of the slow moving object. Experimental outcome depicts that the proposed method has highest detection accuracy with average intersection of union (IOU) score of 94.32% per frame and F1 measure of 97.75% per frame.

Reconstruction of Geometric and Optical Parameters of Non-Planar Objects with Thin Film.

Here, we propose a novel method to estimate the parameters of non-planar objects with thin film surfaces. Being able to estimate the optical parameters of objects with thin film surfaces has a wide range of applications from industrial inspections to biological and archaeology research. However, there are many challenging issues that need to be overcome to model such parameters. The appearance of thin film objects is highly dependent on the surface orientation and optical parameters such as the refractive index and film thickness. First, we therefore analyzed the optical parameters of non-planar objects with thin film surfaces. Next, we proposed and implemented an analysis procedure and demonstrated its effectiveness for studying planar objects with thin film surfaces. Finally, we developed a device to acquire the shapes and optical parameters of objects with thin film surfaces using a camera and demonstrated the effectiveness of our method experimentally. Then, we surveyed the errors caused by the light source. We discussed the difference between the theoretically obtained parameters and experimental data obtained using a hyper spectral camera.

Optical information authentication using phase-only patterns with single-pixel optical detection.

In this paper, we propose and experimentally demonstrate phase-only authentication based on single-pixel optical imaging through scattering media. The propagating wave is sequentially modulated by using a series of random amplitude-only patterns embedded in a spatial light modulator (SLM), and then a series of one-dimensional (1D) intensity values is recorded by the single-pixel (bucket) detector. Subsequently, an intensity pattern just before the SLM is retrieved by using a correlation algorithm and then further propagates back to the object plane in which the object phase pattern is recovered to serve as reference. Then some single-pixel intensity values are randomly selected from the recorded data, and 1-bit compression is applied to the randomly selected data in order to generate 1D binary signals as ciphertext. A series of random amplitude-only patterns corresponding to the randomly selected single-pixel intensity values serve as principal keys. In a scattering environment, the proposed method is able to carry out phase-only authentication without visually rendering the plaintext, which has not been previously studied. It is found that phase-only authentication is sensitive to security keys, and the proposed method possesses high security. In addition, the proposed method is highly robust to noise contamination and data-loss contamination. Optical experimental results demonstrate the feasibility and effectiveness of the proposed method.

Calibration Procedure of Camera With Multifocus Zoom Lens for Three-Dimensional Scanning System

With zoom lenses, both the magnification of the camera and the distance between the lens and the object plane can be changed. Changes to zoom lens magnification is accompanied by changes in the depth of field and the distance between the lens and the object plane, complicating the calibration of zoom cameras-specifically, that of each focus and zoom control, for which separate configurations are required. To overcome this problem, a procedure for the calibration of a multifocus zoom lens in a three-dimensional (3D) scanning system was developed in the present study. Specifically, a pragmatic, five-step calibration procedure was proposed. In the first two steps, the characteristics of the zoom lens were obtained. In the third and fourth steps, the calibration was normalized. Finally, the effectiveness of the process was assessed using a laboratory-developed prototype. High reconstruction accuracy was achieved.

Simple program for computing objective optical properties of magnetic lenses

The paper describes the basic features of a new program denoted Magnetic Electron Lens Optical Properties (MELOP), primarily intended for providing free and simple way to calculate the objective focal properties of rotationally-symmetric electron magnetic lenses with the presence of its axial magnetic field distribution. The calculation is done by solving the paraxial ray equation using the fourth-order Runge-Kutta formula. For specific beam voltage, the program computes the excitation parameter, the object or image plane, the objective principal plane, the objective focal length, the objective magnification, the spherical aberration coefficient, the chromatic aberration coefficient and the magnetic flux density at the object or image plane. These parameters are solved for zero, low, high or infinite magnification condition. The program can handle instantaneously plotting the variations of the calculated parameters relatively. In addition to that, the data can be transferred to xlsx or txt file format.

Light-field imaging for distinguishing fake pedestrians using convolutional neural networks

Pedestrian detection plays an important role in automatic driving system and intelligent robots, and has made great progress in recent years. Identifying the pedestrians from confused planar objects is a challenging problem in the field of pedestrian recognition. In this article, we focus on the 2D fake pedestrian identification based on light-field (LF) imaging and convolutional neural network (CNN). First, we expand the previous dataset to 1500 samples, which is a mid-size dataset for LF images in all public LF datasets. Second, a joint CNN classification framework is proposed, which uses both RGB image and depth image (extracted from the LF image) as input. This framework can fully mine 2D feature information and depth feature information from corresponding images. The experimental results show that the proposed method is efficient to identify the fake pedestrian in a 2D plane and achieves a recognition accuracy of 97.0%. This work is expected to be used in recognition of 2D fake pedestrian and may help researchers solve other computer vision problems.

МЕТОДИКА АВТОМАТИЗИРОВАННОГО УРАВНИВАНИЯ ДАННЫХ МОБИЛЬНОГО ЛАЗЕРНОГО СКАНИРОВАНИЯ

Adjustment is a main step in the preliminary processing of mobile laser scanning (MLS) data. As a result of this step, a point cloud is generated in a certain coordinate system. The modern software, provided with the corresponding surveying system, is capable of performing in automatic mode most stages of MLS data adjustment obtained for territories with different quantity of buildings. With a suf-ficient number of vertically arranged planar objects, such as building walls, the algorithms embedded in the software provide a high accuracy of relative adjustment, which consists in calculating and ap-plying corrections for trajectories obtained with re-scanning the same area. Absolute adjustment can also be carried out automatically, subject to the rules for placing control points in order to automatically detect them. This kind of adjustment involves transforming a point cloud with using control point coordinates measured with more accurate surveying methods. The accuracy of automatic relative adjustment can be significantly reduced with the almost complete absence of vertical flat objects. In this case, it is necessary to develop additional adjustment techniques capable of using not only flat objects of a large area, but also vertical objects, such as road signs and poles. Comprehensive technique of MLS data adjustment, which can use information on the position of road signs and poles for territories with an insufficient number of vertical flat objects is proposed. The accuracy estimation of both the relative and absolute MLS data adjustment according to the proposed technique was carried out. The choice of the required control point density for territories with different quantity of buildings is explained.

Comparison between Variance and Edge Methods for Measuring Image Resolution Properties in Digital Mammography

We studied the image resolution properties in digital mammography using the variance and edge response function methods. The associated measurements were made using a polymethylmethacrylate phantom of 0-40 mm thickness while maintaining the incident dose to the detector constant, as well as with and without using the phantom but by varying the level of exposure to the detector. The results obtained using the two methods were compared on the object plane of the mammography unit with compensation for the magnification and rejection of the scattered radiation. In this unit, the imaging process of resolution enhancement may be performed according to the phantom thickness, shape of test device, exposure level, and so on. The modulation transfer function values of the variance method were slightly higher than those of the edge method, approximately 6% at 2 cycles/mm and 8% at 4 cycles/mm without resolution enhancement processing. We concluded that the variance method is more suitable than the edge method for the constancy test or quality control because of its lower coefficient of variation.

Fault-Tolerant Application-Specific Topology-Based NoC and Its Prototype on an FPGA

Application-Specific Networks-on-Chips (ASNoCs) are suitable communication platforms for meeting current application requirements. Interconnection links are the primary components involved in communication between the cores of an ASNoC design. The integration density in ASNoC increases with continuous scaling down of the transistor size. Excessive integration density in ASNoC can result in the formation of thermal hotspots, which can cause a system to fail permanently. As a result, fault-tolerant techniques are required to address the permanent faults in interconnection links of an ASNoC design. By taking into account link faults in the topology, this paper introduces a fault-tolerant application-specific topology-based NoC design and its prototype on an FPGA. To place spare links in the ASNoC topology, a meta-heuristic algorithm based on Particle Swarm Optimization (PSO) is proposed. By taking link faults into account in ASNoC design, we also propose an application mapping heuristic and a table-based fault-tolerant routing algorithm. Experiments are carried out for a specific link and any link fault in fault-tolerant topologies generated by our approach and approaches reported in the literature. For the experimentation, we used the multi-media applications Picture-in-Picture (PiP), Moving Pictures Expert Group (MPEG) - 4, MP3Encoder, and Video Object Plane Decoder (VOPD). Experiments are run on software and hardware platforms. The static performance metric communication cost and the dynamic performance metrics network latency, throughput, and router power consumption are examined using software platform. In the hardware platform, the Field Programmable Gate Array (FPGA) is used to validate proposed fault-tolerant topologies and analyze performance metrics such as application runtime, resource utilization, and power consumption. The results are compared with the existing approaches, specifically Ring topology and its modified versions on both software and hardware platforms. The experimental results obtained from software and hardware platforms for a specific link and any link fault show significant improvements in performance metrics using our approach when compared with the related works in the literature.

Теория и расчет электростатических электронных зеркал с учетом релятивистских эффектов

Using the central particle method, the equations of the trajectory of charged particles in an axisymmetric electrostatic mirror are obtained with an accuracy of the third order of smallness inclusive with account for relativistic effects. The conditions for spatial focusing and the coefficients of spatial aberrations in the Gaussian plane of the mirror image are determined with account for relativism. By means of numerical calculations, conditions for simultaneous elimination of spherical and axial chromatic aberrations are determined, taking into account relativistic effects, in an axisymmetric electrostatic mirror when the object plane of the mirror is aligned with its focal plane. It is shown that account for high particle velocities leads both to a shift in the position of the Gaussian image plane and a change in the focusing quality.

A Focus-Measurement Based 3D Surface Reconstruction System for Dimensional Metrology

Image focus is an important parameter which depends on various other parameters of an imaging system. One among them is the distance of the object plane from the lens. This parameter is referred as the depth in computer vision literatures. Since depth affects the focus level of pixels in an image, focus measurement can be used to interpret the depth of points of an object. The paper presents the details of the novel indigenously developed automated measurement system which can perform high-precision movements based on feedback control. The measurement system is inspired by classical systems used in techniques such as shape from focus. This system fundamentally being a mechatronics system integrates a high-precision multi-stage translation mechanism which is actuated with a servo motor with sensors such as camera, linear encoder, optical limit switches. The hardware interface is developed for automated measurement through a USB data acquisition system. The paper presents the methodology of surface reconstruction and detailed description of the various challenges encountered in the integration. The surface reconstruction is performed for various millimetres and sub millimetres level engineered specimens. The paper presents the future direction of research and also various potential application possibilities for such measurement setup.

AN OPTIMIZED ALGORITHM FOR COMPUTING THE VORONOI SKELETON

The skeleton-based representation is widely used in such fields as computer graphics, computer vision and image processing. Therefore, efficient algorithms for computing planar skeletons are of high relevance. In this paper, we propose an optimized algorithm for computing the Voronoi skeleton of a planar object with holes, which is represented by a set of polygons. Such skeleton allows us to use efficiently the properties of the underlying Voronoi diagram data structure. It was shown that the complexity of the proposed Voronoi-based skeletonization algorithm is O(N log N), where N is the number of polygon’s vertices. We have also proposed theoretically justified optimization heuristic based on polygon/polyline simplification algorithms. In order to evaluate and prove the efficiency of the heuristic, a series of computational experiments were conducted involving the polygons obtained from MPEG 7 CE-Shape-1 dataset. We have measured the execution time of the skeletonization algorithm, computational overheads related to the introduced heuristics and also the influence of the heuristic onto accuracy of the resulting skeleton. As a result, we have established the criteria, which allow us to choose the optimal heuristics for our skeletonization algorithm depending on the system’s requirements.

Regarding the ancestral and direct objects of non-violent crime against the sexual integrity of a minor

The article analyzes the current state of the study of ancestral and direct objects of crimes against sexual freedom and sexual integrity of a person. The conclusion about the contradiction of some views of scientists on the content and interaction of sexual freedom and sexual inviolability as objects of criminal justice is substantiated. The position on the content of sexual inviolability as a universal social and biological condition and object of criminal legal protection, which has a multilevel social legal regulation (protection) and is distinguished: a) value, b) regulatory, c) medical, d) information and e) physical levels of sexual integrity. The problem of the relation between sexual freedom and sexual inviolability as objects of criminal protection in the doctrine of criminal law is resolved controversially. The established doctrinal provisions and their own views on the subject of the study, as well as the criminal legislation of Ukraine, which stood for the protection of sexual freedom and sexual inviolability of a person, an attempt was made to redefine the generic and direct objects of non-violent sexually assaulting crimes. minors. Relations with the absolute informational (mental) and physical (physical) sexual integrity of a minor are, first of all, protected by criminal legal means. These relationships are in the plane of the generic object, are its component part and form a homogeneous formation in the form of sexual inviolability of the person with other elements. Certainly, the allocation of information (mental) and physical (physical) components of sexual integrity of a minor is to some extent conditional. It is impossible to negatively affect the physical integrity, not to touch its mental component. Conversely, the mental impact on sexual integrity is bound to adversely affect physical integrity. The physical component of sexual integrity is harmed in all cases of sexual abuse of the perpetrator with the victim, which have many forms of sexual manipulation with the victim's body. Equally socially dangerous is sexual misconduct of a minor by talking cynically, displaying pornographic and erotic content, etc.

Perspective registration and multi-frame super-resolution of license plates in surveillance videos

One task often encountered in surveillance videos is the recognition of a target—e.g. the license plate of a vehicle. Often, the quality of a single video frame does not permit a reliable recognition. If multiple frames are available, it is possible to combine them in order to generate a single image with lower noise (frame averaging) and/or higher resolution (super-resolution). In order for these techniques to work, it is necessary to accurately estimate the motion of the object of interest in the recorded footage.In this paper, we introduce a method capable of accurately computing the perspective transformation that describes the motion of a planar object. The method minimizes the squared distance between the transformed image and a reference, computed over a user-defined region of interest, and uses the partial derivatives in order to significantly speed up the computation. This approach is inspired by the well known Kanade–Lucas–Tomasi feature tracker.

Coaxial spectroscopic imaging ellipsometry for volumetric thickness measurement.

We propose spectroscopic imaging ellipsometry that can measure spectral ellipsometric signals in the entire field of view simultaneously without areal scanning or operation of polarization devices. The proposed imaging ellipsometry is configured in a coaxial optical structure so that the high magnification objective lens is applicable and the spatial resolution is highly increased. Without the operation of polarization components and to efficiently obtain the spectral data in the object plane, the ellipsometric parameters are encoded into the high frequency in the spectral domain and are measured by an imaging Michelson interferometer. The volumetric thickness measurement by the proposed method was verified by comparing the thickness results of the SiO2/Si sample that has four different thicknesses with commercial ellipsometer results.

PIV measurements using refraction at a solid–fluid interface

Laser light sheet refraction at the fluid flow–window interface is proposed to perform fluorescent particle image velocimetry (PIV) measurements, in particular for cases in which optical access limits the possibilities of illuminating a flow with a planar collimated light sheet. The study of laser sheet propagation in the present measurement method is led by ray tracing to quantify the illumination intensity. To describe the limitations of this developed PIV version (refracted PIV (R-PIV)), we proposed a cross-correlation model (CCM) for analyzing image pairs that is an extension of the models used in the cases of µ-PIV or planar PIV (P-PIV) techniques. This CCM accounts for the R-PIV optical constraints of (1) in-depth and longitudinal inhomogeneities of the light sheet refraction at the location of the object plane or (2) integration in depth of the fluorescence from seeding particles. This R-PIV and the P-PIV techniques are further compared in the case of an academic pipe flow for which the analytic solution is known. Our extended CCM function is finally applied, given the theoretical flow velocity, the flow illumination and the seeding flow parameters, to analyze error levels in determining the real flow velocity field.

Calibrating mirror-assisted multi-view digital image correlation system using a speckled planar object

Recently, a novel low-cost and easy-to-implement mirror-assisted multi-view digital image correlation (MV-DIC) technique that uses only a vertically arranged binocular stereo-digital image correlation (stereo-DIC) system and two planar mirrors was proposed for panoramic/dual-surface kinematic field measurements. The mirror-assisted MV-DIC, which is equivalent to a regular MV-DIC system comprising three/two identical stereo-DIC systems, can simultaneously measure three/two different regions of a test sample. To perform panoramic/dual-surface kinematic field measurements with this technique, one of the most important procedures is accurately calibrating the reflection transformation of each mirror to transform all measured regions to a common world coordinate system. Previous works calibrate the reflection transformation by decorating speckle patterns on the mirrors or adjusting the mirrors to various poses, which either occupies precious spatial resolution of the sensor or is complicated in implementation. In this work, an easy-to-implement and practical method that employs only a speckled planar object is proposed to calibrate the reflection transformation of the planar mirrors. The effectiveness and accuracy of the proposed method are well evaluated and validated. Compared with existing methods, the proposed method holds the advantage of being efficient in sensor utilization and simple in implementation and is therefore highly recommended for the practical use of the mirror-assisted MV-DIC technique.