Video Digital Image Processing Research Articles

Retracted: Sports Auxiliary Training Based on Computer Digital 3D Video Image Processing.

[This retracts the article DOI: 10.1155/2022/2105790.].

Sports Auxiliary Training Based on Computer Digital 3D Video Image Processing.

With the continuous development of social economy, sports have received more and more attention. How to improve the quality of sports has become the focus of research. The computer digital 3D video image processing is introduced in this paper, taking shooting as the starting point, in which computer digitization technology is used to collect images of sequence targets through combining the operation flow of shooting, monitor the results and data of shooting and process 3D video images, conduct the analyze and mine according to the corresponding statistical processing results, and evaluate the corresponding training. The simulation experiment proves that the computerized digital 3D video image processing is effective and can scientifically support sports-assisted training.

Mathematical Modeling and Simulation of Table Tennis Trajectory Based on Digital Video Image Processing

Digital sports training based on digital video image processing promises to reduce the reliance on the experience of coaches in the table tennis training process and to achieve a more general physical education base. Based on this approach, this paper describes the specific forms of exercise content, movement characteristics, and skill levels in the table tennis framework and specifies the calculation methods of motion capture and movement characteristics suitable for table tennis. Meanwhile, to further improve the accuracy of the inertial motion capture system in restoring the position posture of the trainees, this paper improves the original inertial motion capture system from two aspects: contact judgment of both feet and correction of the position posture based on the contact position constraint. The simulation results show that the corrected human posture has good action smoothness. This paper first proposes a knowledge-based generic sports-assisted training framework based on generalizing the traditional sports training model. The framework contains four main modules: domain knowledge, trainees, sport evaluation, and controller. The domain knowledge module is a digital representation of the knowledge of the exercise content, improvement instructions, and skill indicators of the sport; the trainee module is the active response of the trainee to the exercise content and improvement instructions; the motion evaluation module uses motion capture technology to obtain the raw motion data of the trainee and further calculates the motion characteristics; the controller module proposes improvement instructions to the trainee or makes him/her practice new content based on the results of the motion evaluation. Based on the results of the motion evaluation, the controller module proposes improvement instructions or makes the trainee practice new content until the trainee achieves the desired goal.

Elimination of wetting study flaws in unsaturated vapors based on Laplace fit parameters

Performing digital video image processing of sessile droplets and Laplace fit optimization is one of the most widely used modern techniques to measure the contact angle. The attractive feature of this approach is related to the possibility of simultaneous determination of numerous droplet parameters, such as contact angles, droplet surface tension, droplet surface area and droplet volume. However, lately in the literature, the analysis of the droplet shape is usually restricted by the contact angle determination, and the experiments are performed under open atmospheric conditions without simultaneous monitoring of the other droplet parameters. In this brief note, it is shown how wettability measurements under conditions of undersaturated water vapor affect the observed water droplet parameters.

Analytic Model for Multi-point Large-Radius Bending of Steel Sheets

While the majority of industrial sheet bending processes consist of conventional air bending, more complex bending processes such as multi-point bending are also utilized. Multi-point bending involves forming several bends simultaneously with changing contact conditions. Of the various models that may be employed to simulate such processes, analytic models are most attractive for industrial applications as they are time-efficient, strongly theoretically supported and easily extended to a wide range of dies layouts without the need of additional experimental data. In this paper a new analytic model is presented to predict the forming forces, the deformation of the sheet and the springback. The model is based on the literature around large-radius air bending. The geometry of the sheet is determined at each moment as a function of the tool’s positions. The reaction forces are calculated based on the equilibrium of forces and moments and the springback is calculated based on the elastic unloading of the internal bending forces. The model has been compared with a more time consuming finite element (FE) model and the geometry of the sheet has been experimentally verified by means of digital processing of video images. The proposed analytic model shows good agreement with the computational FE model and it is demonstrated to be a robust tool for calculation of the bending characteristics.

Experimental study on gas-liquid flow characteristics of submerged air jets

The gas-liquid flow structure and interfacial behavior of submerged air jets were investigated experimentally using high speed digital video camera and image processing techniques. The jet pressure ratio varied from 1.8 to 4.8 in the experiment. And results from different jet nozzles were processed and compared. Statistical characteristics of the jet diameters along the axial distance were obtained and analyzed. Time series analysis was implemented to study the interface unsteadiness by calculating the gas-liquid interface deviation. The results showed that the jet diameters increase first linearly then nonlinearly and its growth rate decreases along the axial distance. The reason for the divergence between the result of this experiment and those done by other researchers was analyzed. Comparing the results of different pressure ratios and nozzle diameters, we found that larger jet pressure ratios have larger jet diameters and nozzle diameters nearly have no bearing on the distribution of dimensionless jet diameters. The interface unsteadiness in low and high pressure ratios exhibited totally distinct properties. And a minimum unsteady value was found along the axis of the air jets.

Research and development of an indoor navigation system based on the digital processing of video images

The paper describes the development of an indoor navigation system of an autonomous mobile robot using image processing methods of industrial television. The system analyzes the surrounding space with a simple monocular TV camera. Color beacons placed on objects in the environmental are used as reference points. The developed system is tested under different environmental conditions. The mobile robot navigation accuracy is evaluated for the case of the simultaneous detection of two beacons.

<b>Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing

Detachment of coffee fruit is usually accomplished by means of mechanical impacts and vibrations applied to the plant. Modal properties of the coffee fruit-stem system represent important information for efficient and selective harvesting. This study aimed to determine the modal parameters of the coffee fruit-stem system, such as natural frequency and damping coefficient, using high speed digital videos. With image processing techniques, it was obtained the resulting displacement of the system subjected to an impulse. The modal parameters were determined by the logarithmic decrement method, considering the system as underdamped. The use of high-speed video and digital image processing techniques allowed the simple and reliable determination of modal parameters of the coffee fruit-stem system. Natural frequencies for the coffee fruit-stem system were 11.62 and 13.29 Hz; the damping coefficient was 0.0253 and 0.029 N s m -1 , and the equivalent stiffness was 8.61 and 7.09 N m -1 for red and green ripening stages, respectively. It was found overlap of resonance bands, between the ripening stages red and green, hindering the selective mechanical detachment in the first natural frequency range of the coffee fruit-stem system. Keywords: image segmentation, mechanical harvesting, mechanical vibrations. Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing Detachment of coffee fruit is usually accomplished by means of mechanical impacts and vibrations applied to the plant. Modal properties of the coffee fruit-stem system represent important information for efficient and selective harvesting. This study aimed to determine the modal parameters of the coffee fruit-stem system, such as natural frequency and damping coefficient, using high speed digital videos. With image processing techniques, it was obtained the resulting displacement of the system subjected to an impulse. The modal parameters were determined by the logarithmic decrement method, considering the system as underdamped. The use of high-speed video and digital image processing techniques allowed the simple and reliable determination of modal parameters of the coffee fruit-stem system. Natural frequencies for the coffee fruit-stem system were 11.62 and 13.29 Hz; the damping coefficient was 0.0253 and 0.029 N s m -1 , and the equivalent stiffness was 8.61 and 7.09 N m -1 for red and green ripening stages, respectively. It was found overlap of resonance bands, between the ripening stages red and green, hindering the selective mechanical detachment in the first natural frequency range of the coffee fruit-stem system.

Parameter Modification Guiding Optimization Design and Tests of a Rotary Transplanting Mechanism for Rice Plug Seedlings

A parameter modification guiding optimization method combined with fuzzy optimization was applied to improve the design of a rice plug seedling transplanting mechanism using a planetary gear train with elliptical gears and an incomplete non-circular gear. The laboratory kinematics was examined, and seedling transplanting tests were conducted. Based on the work principle analysis of the transplanting mechanism for rice plug seedlings, numerical kinematic objective functions were established using fuzzy objectives requirements such as transplanting trajectory and posture. Subordinate functions were determined to describe the objective functions. Then the optimization model of the mechanism was constructed which took the value of the subordinate degree of objective functions as the optimization objectives and the motion interference, height of the transplanting trajectory and mechanical structure as the constraint conditions. Parameter guiding optimization software based on Visual Basic 6.0 was developed independently to determine a set of better parameters for the mechanism, which can reduce dependence on expert experience and improve the efficiency of the design. The mechanism structure was designed, and a physical prototype was manufactured. A high-speed digital video camera and image processing technology were used to perform the kinematics bench tests to obtain the transplanting trajectory and posture of the mechanism. The consistency between the test results and theoretical results shows that the optimized mechanism can satisfy the transplanting requirements and that the design method and results are also accurate. Finally, rice seedling transplanting tests were conducted to verify the transplanting performance of the mechanism. The mechanism extracted 200 seedlings per minute per row with a success ratio of 95.89%; the mechanism also displayed a good effect in seedling pushing, showing that the mechanism could be applied in a practical machine.

Field Measurement of Fishing Boats Generated Waves

Ship generated waves can cause banks erosion as well as disturbance on stationary boats. Studies have shown that the boat generated waves are dependent on and affected by environmental factors and vessel parameters. The main environmental factors are tidal and current direction, and for vessel parameters are speeds and hullforms. This paper describes a full-scale experimental work to measure wave heights and wave angle direction on boat generated waves. The measurement method used in this paper is based on the analysis of digital video recordings and image processing techniques.

Study of a single coarse bubble behavior in the presence of D.C. electric field

An experimental study was carried out to investigate the effects of both uniform and non uniform D.C. electric fields on the motion and deformation of a single coarse bubble rising in dielectric liquid media. Bubble shape, aspect ratio, rising path, rise velocity and maximum inclination angle were determined by digital processing of high speed video images (600 fps). Three different viscosities of silicone oil were utilized as a base of quiescence media. Results show that the bubble deformation under the influence of electric field increases at low Re number. Moreover bubble deviation from its rising path increases by adding to electric field strength as well as reduction in liquid viscosity and subsequently the more inclination angle is observed. Bubble velocity in the region of steady and unsteady motion is not affected by applied electric field due to high hydrodynamic forces associated with relatively large bubble; though, its detachment is improved by the applied electric field. Our observations revealed that in the case of coarse bubbles, where electric forces are negligible in comparison with high hydrodynamic instability, EHD flow plays an important role in controlling the motion. This investigation can be helpful in giving a better insight of coarse bubble's behavior under the influence of electric fields and also provides a means for its manipulation in scientific problems as well as engineering applications

EFFECTS OF PSEUDOPLASTICITY ON SPREAD AND RECOIL DYNAMICS OF AQUEOUS POLYMERIC SOLUTION DROPLETS ON SOLID SURFACES

The postimpact spreading and recoil behavior of millimeter-size liquid droplets of pure water, water–glycerol solution, and non-Newtonian aqueous solutions of medium-grade hydroxyl ethyl cellulose (HEC 250 MR) on dry horizontal hydrophobic (Teflon) and hydrophilic (glass) substrates is presented. The drop spread–recoil dynamics are captured using a high-speed high-resolution digital video recording and image processing. The non-Newtonian effects of aqueous polymeric solutions on postimpact spreading are contrasted with those for a water–glycerol solution with identical surface tension and zero-shear rate viscosity. For a broad range of drop Weber numbers (20 ≤ We ≤ 200), dynamic visualized records of impact, spreading, and recoil are presented along with their measured temporal variations in dropdiameter-scaled spread and film height. The shear-rate-dependent viscosity of the polymer solution is found to give rise to highly complex spread–recoil dynamics compared to Newtonian liquids. During initial spread, because the shear rate tends to be high, shear-thinning or pseudoplasticity effects manifest in polymer solution drops to alter their spread dynamics. Contrarily, during recoil their higher low-shear apparent viscosity tends to retard recoil and dampen shape oscillations. Shear-rate-dependent non-Newtonian behavior is further seen at low We (low shear rate during spreading), where the maximum spread of HEC solution droplets is comparable to that of high-viscosity water–glycerol solution, whereas at high We (high shear rate during spreading), their maximum spreads are closer to those of low-viscosity water droplets.

Solvent Penetration Rate in Tablet Measurement Using Video Image Processing

We describe a simple technique for the measurement of solvent penetration rates into spray-dried lactose (DCL) tablets and tablets made of blended materials using digital video image processing. The results of the experimental study show that the penetration rate in some cases appears to be close to linear with time, which corresponds to non-Fickian or Case II-type diffusion. We discuss relevant capillary invasion models in order to explain the observed penetration rate. The proposed technique allows fast diffusion rate acquisition/processing and can be useful when designing immediate release tablets that require a large number of measurements corresponding to different formulations and processing parameters.

Digital Video Image Processing from Dental Operating Microscope in Endodontic Treatment

Recently, optical microscopes have been used in endodontic treatment, as they offer advantages in terms of magnification, illumination, and documentation. Documentation is particularly important in presenting images to patients, and can take the form of both still images and motion video. Although high-quality still images can be obtained using a 35-mm film or CCD camera, the quality of still images produced by a video camera is significantly lower. The purpose of this study was to determine the potential of RegiStax in obtaining high-quality still images from a continuous video stream from an optical microscope. Video was captured continuously and sections with the highest luminosity chosen for frame alignment and stacking using the RegiStax program. The resulting stacked images were subjected to wavelet transformation. The results indicate that high-quality images with a large depth of field could be obtained using this method.

Analysis of wetting as an efficient method for studying the characteristics of coatings and surfaces and the processes that occur on them: A review

The use of a method of studying wetting both for the research of fundamental problems of surface physicochemistry, such as obtaining information on the structure and properties of the interface and the processes that occur with its participation, and for technological applications related to the preparation of new materials and coatings is analyzed. The fundamental relationships between the contact angle and the thermodynamic and geometric characteristics of the surface are discussed; the factors that have an effect on the contact angle value on nanocomposite surfaces are analyzed. It is shown that recent advances in digital processing of video images provide a qualitatively new level of measurement of contact angles and make the analysis of surface wetting one of the most efficient experimental methods for studying the processes that occur at interfaces. In some cases, the accumulated basic knowledge about the relationship between the measured contact angle and the properties of the surface under study makes it possible to rapidly and reliably obtain detailed information about the roughness, chemical composition, and topology of the surface without using expensive equipment; in other cases, it provides additional information that makes it possible to reveal the mechanisms of the surface phenomena under study. As a case in point, we describe the use of techniques of analysis of wetting for determining the surface porosity and surface topology, for estimating the pattern of interaction between polymer materials and aqueous media, and for revealing the efficiency of anticorrosion coatings on metal surfaces.

Biological Early Warning System for Prawn Aquiculture

Water quality monitoring through observing physiological or behavioral changes of living organisms has been arouse much attentions from academia and industry during past years. In this study, a biological early warning system was designed to record prawn behavior characteristics subjected to different water qualities. The system consists of a specially-designed water container, a digital video recorder and image processing software. Prawn samples were divided into three groups for calibration and one group for validation. The targeted water quality parameters includes water salinity, pH and dissolved oxygen concentration (DOC) that were altered by adding different chemicals in the experimental water container. The position of a prawn was marked by its dark feces in its body. The movement of the prawn was then tracked by its position-time sequence, which allows calculating the moving speed of the prawn. The calibration result shows that DOC changes make great impact on prawn behavior while water salinity and pH do not. When DOC is above 3.0 mg/l, prawns move at about 80 pixels/s; when DOC is between 2.6 and 1.74 mg/l, prawn moves at about 120 pixels/s; and when DOC is below 1.2 mg/l, prawns move at the speed of 1000-1200 pixels/s. The validation set of prawns with DOC changing from 1.82 to 0.54 mg/l confirms the calibration observations. It is concluded that the proposed approach is promising for water quality monitoring, especially DOC in aquiculture environment.

Field observations of waves generated by passing ships: A note

This short contribution reports the results of a field study on the nearshore characteristics of waves generated by both conventional and high speed passenger ferries. The field observations took place in the late summer of 2005, at a beach close to the port of Mytilene (Island of Lesbos, Greece), and involved the visual observation of ship waves, using digital video recordings and image processing techniques. The results showed that passage of the fast ferry was associated with a longer, more complex and energetic nearshore event; this event not only did include higher nearshore waves (up to 0.74 m) and was organised in different wave packets, but it was also an order of magnitude longer (∼ 680 s) than the conventional ferry event. Regarding the effects on beach sediment dynamics, the fast ferry waves were estimated to be very efficient in mobilising the nearshore sediments in contrast to those of the conventional ferry. The fast ferry service appears to generate daily prolonged nearshore events, which contain waves with higher energy than those expected from the normal summer wind wave regime of the area; these events also include some high and very steep waves, which can be particularly erosive. Therefore, fast ferry wakes may have considerable impacts on the seasonal beach sediment dynamics/morphodynamics and the nearshore benthic ecology, as well as they may pose significant risks to bathers, affecting the recreational use of the beaches exposed to fast ferry traffic. Finally, the study has shown that satisfactory field observations of the nearshore characteristics of ship-generated (and wind) waves can be obtained using inshore deployments of calibrated poles, digital video cameras and appropriate image processing algorithms.

Evaluation of the Time Course of Plasma Extravasation in the Skin by Digital Image Analysis

Plasma extravasation (PE) can be triggered by neurotransmitters as part of a neuroinflammatory response. We present a technique based on video digital image processing that provides a simple, noninvasive, reliable, and quantitative method for measuring the time course and extent of PE in the skin. After intravenous infusion of Evans Blue dye, stimulation of the saphenous nerve caused the skin on the dorsomedial region of the hind paw to become dark blue. The change in reflectance of the skin was recorded with a monochrome video camera. Images were digitized and analyzed with inexpensive or public domain software. The change in pixel intensity was determined in a selected region. Stimulation at 4 Hz caused greater darkening of the skin than at 1 Hz, and this was confirmed with spectrophotometric measurements of Evans Blue content. The NK1 receptor antagonist CP-99, 994 blocked saphenous nerve and substance P–induced darkening of the skin. The results indicate that our measurement gives results similar to those obtained with classic methods that are widely accepted as an indication of PE. This simple and quick method reveals the extent, time course, and location of PE, is cheap to implement and easy to learn, and thus represents a useful and alternative tool for studies of PE and its modulation. Perspective This article presents a simple technique with which to evaluate the time course and extent of plasma extravasation in the skin of animal models of neuroinflammation. The technique is well suited to answer questions about basic physiologic mechanisms of neuroinflammation and should also be useful in drug testing studies.

Using signal processors for automatic image processing in real time

This paper discusses the possibility of using signal processors for automatic digital processing of video images in real time. A technique is proposed for estimating the throughput of the parallel signal processors needed to ensure real-time processing. Using typical examples, it is demonstrated that existing signal processors have inadequate throughput, which can be increased by creating specialized and multiprocessor systems. © 2005 Optical Society of America

Quantifying agitation in sedated ICU patients using digital imaging.

Agitation is a significant problem in the Intensive Care Unit (ICU), affecting 71% of sedated adult patients during 58% of ICU patient-days. Subjective scale based assessment-methods focused primarily on assessing excessive patient motion are currently used to assess the level of patient agitation, but are limited in their accuracy and resolution. This research quantifies this approach by developing an objective agitation measurement from patient motion that is sensed using digital video image processing. A fuzzy inference system (FIS) is developed to classify levels of motion that correlate with observed patient agitation, while accounting for motion due to medical staff working on the patient. Clinical tests for five ICU patients have been performed to verify the validity of this approach in comparison to agitation graded by nursing staff using the Riker Sedation-Agitation Scale (SAS). All trials were performed in the Christchurch Hospital Department of Intensive Care, with ethics approval from the Canterbury Ethics Committee. Results show good correlation with medical staff assessment with no false positive results during calm periods. Clinically, this initial agitation measurement method promises the ability to consistently and objectively quantify patient agitation to enable better management of sedation and agitation through optimised drug delivery leading to reduced length of stay and improved outcome.