scholarly journals 3D Foot Reconstruction Based on Mobile Phone Photographing

2021 ◽  
Vol 11 (9) ◽  
pp. 4040
Author(s):  
Lulu Niu ◽  
Gang Xiong ◽  
Xiuqin Shang ◽  
Chao Guo ◽  
Xi Chen ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Structure From Motion ◽  
High Price ◽  
Reconstruction Method ◽  
Sparse Model ◽  
Foot Model ◽  
Foot Reconstruction ◽  
Large Measurement ◽  
Camera Position ◽  
Large Measurement Error

Foot measurement is necessary for personalized customization. Nowadays, people usually obtain their foot size by using a ruler or foot scanner. However, there are some disadvantages to this, namely, large measurement error and variance when using rulers, and high price and poor convenience when using a foot scanner. To tackle these problems, we obtain foot parameters by 3D foot reconstruction based on mobile phone photography. Firstly, foot images are taken by a mobile phone. Secondly, the SFM (Structure-from-Motion) algorithm is used to acquire the corresponding parameters and then to calculate the camera position to construct the sparse model. Thirdly, the PMVS (Patch-based Multi View System) is adopted to build a dense model. Finally, the Meshlab is used to process and measure the foot model. The result shows that the experimental error of the 3D foot reconstruction method is around 1 mm, which is tolerable for applications such as shoe tree customization. The experiment proves that the method can construct the 3D foot model efficiently and easily. This technology has broad application prospects in the fields of shoe size recommendation, high-end customized shoes and medical correction.

scholarly journals Refractive Two-View Reconstruction for Underwater 3D Vision

2019 ◽  
Vol 128 (5) ◽  
pp. 1101-1117 ◽  
Author(s):  
François Chadebecq ◽  
Francisco Vasconcelos ◽  
René Lacher ◽  
Efthymios Maneas ◽  
Adrien Desjardins ◽  
...  
Keyword(s):  
Structure From Motion ◽  
Real Data ◽  
Reconstruction Method ◽  
Underwater Imaging ◽  
Shape Estimation ◽  
Camera Model ◽  
Projection Model ◽  
3D Vision ◽  
Object Distance ◽  
View Reconstruction

AbstractRecovering 3D geometry from cameras in underwater applications involves the Refractive Structure-from-Motion problem where the non-linear distortion of light induced by a change of medium density invalidates the single viewpoint assumption. The pinhole-plus-distortion camera projection model suffers from a systematic geometric bias since refractive distortion depends on object distance. This leads to inaccurate camera pose and 3D shape estimation. To account for refraction, it is possible to use the axial camera model or to explicitly consider one or multiple parallel refractive interfaces whose orientations and positions with respect to the camera can be calibrated. Although it has been demonstrated that the refractive camera model is well-suited for underwater imaging, Refractive Structure-from-Motion remains particularly difficult to use in practice when considering the seldom studied case of a camera with a flat refractive interface. Our method applies to the case of underwater imaging systems whose entrance lens is in direct contact with the external medium. By adopting the refractive camera model, we provide a succinct derivation and expression for the refractive fundamental matrix and use this as the basis for a novel two-view reconstruction method for underwater imaging. For validation we use synthetic data to show the numerical properties of our method and we provide results on real data to demonstrate its practical application within laboratory settings and for medical applications in fluid-immersed endoscopy. We demonstrate our approach outperforms classic two-view Structure-from-Motion method relying on the pinhole-plus-distortion camera model.

scholarly journals Starbucks in the World

2019 ◽  
Vol 10 (3) ◽  
pp. 99-110
Author(s):  
Hui-Jung Chuang
Keyword(s):  
Young People ◽  
Mobile Phone ◽  
The United States ◽  
High Price ◽  
High Quality ◽  
The United Kingdom ◽  
The World ◽  
Coffee Market ◽  
Tv Commercials ◽  
Coffee Shops

Abstract Many young people want to work in coffee shops or even open coffee shops, so they set off a wave of entrepreneurship, but according to a survey by the world magazine, Entrepreneurial momentum is strong in Taiwan, and the proportion of entrepreneurship is higher than that of the United Kingdom, Singapore, South Korea, and Japan, second only to the United States, but Taiwan’s entrepreneurial “death rate” is also significantly higher than these countries. According to the information of the chief accounting office, Taiwan’s entrepreneurship rate was far greater than the rate of business closure before 2000, but after 2000, the chances of successful entrepreneurship fell sharply. Also, many people are used to sipping a cup of coffee in the morning to start a good day. In recent years, the coffee market has developed rapidly in Taiwan, and convenience stores have launched promotional advertisements for cheap coffee. However, we have found that Starbucks, a high-priced coffee brand, has not joined the ranks of cheap coffee. They still maintain their high price and high quality. The most important thing is that we did not see Starbucks ads on any TV commercials or print media. Why did Starbucks not use advertising, but still stand in front of the coffee market? Starbucks products often seem as a luxury. The most common cup of American coffee costs NT$100, whereas a cup of coffee at the convenience store costs only NT$45. Why are so many people willing to pay twice the price? The main reason is the quality and service of Starbucks. Enter into Starbucks, customers can order the beverages without the ice and full of milk, or anything which you want. Customers also enjoy free WIFI in the store, provide mobile phone charging or laptop socket, the staff will serve you with the most enthusiastic attitude. The brand advertise that as long as you ask for what he can do, the partners will meet your needs. In addition, Starbucks products are quite diversified, attracting a large number of consumer groups. From high-quality coffee, decaffeinated beverage juices and Frappuccino, to localized tea drinks in the Greater China region, the needs of every guest are met. Apart from the food, it also sells coffee makers, coffee beans, trendy mobile phone cases that are popular among young people, mobile power supplies, CDs in the store, and mugs and accompanying cups for various themes.

scholarly journals Self-Adaptive Image Reconstruction Inspired by Insect Compound Eye Mechanism

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jiahua Zhang ◽  
Aiye Shi ◽  
Xin Wang ◽  
Linjie Bian ◽  
Fengchen Huang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Compound Eye ◽  
Signal To Noise Ratio ◽  
Processing System ◽  
Reconstruction Method ◽  
Sparse Model ◽  
Reconstruction Methods ◽  
Adaptive Reconstruction ◽  
Distinct Block ◽  
Block Effect

Inspired by the mechanism of imaging and adaptation to luminosity in insect compound eyes (ICE), we propose an ICE-based adaptive reconstruction method (ARM-ICE), which can adjust the sampling vision field of image according to the environment light intensity. The target scene can be compressive, sampled independently with multichannel through ARM-ICE. Meanwhile, ARM-ICE can regulate the visual field of sampling to control imaging according to the environment light intensity. Based on the compressed sensing joint sparse model (JSM-1), we establish an information processing system of ARM-ICE. The simulation of a four-channel ARM-ICE system shows that the new method improves the peak signal-to-noise ratio (PSNR) and resolution of the reconstructed target scene under two different cases of light intensity. Furthermore, there is no distinct block effect in the result, and the edge of the reconstructed image is smoother than that obtained by the other two reconstruction methods in this work.

Refraction-Based Bundle Adjustment for Scale Reconstructible Structure from Motion

2018 ◽  
Vol 30 (4) ◽  
pp. 660-670 ◽  
Author(s):  
Akira Shibata ◽  
Yukari Okumura ◽  
Hiromitsu Fujii ◽  
Atsushi Yamashita ◽  
Hajime Asama ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Structure From Motion ◽  
Error Function ◽  
Bundle Adjustment ◽  
Reconstruction Method ◽  
Actual Measurement ◽  
3D Measurements ◽  
Absolute Scale ◽  
The Absolute ◽  
Motion Method

Structure from motion is a three-dimensional (3D) reconstruction method that uses one camera. However, the absolute scale of objects cannot be reconstructed by the conventional structure from motion method. In our previous studies, to solve this problem by using refraction, we proposed a scale reconstructible structure from motion method. In our measurement system, a refractive plate is fixed in front of a camera and images are captured through this plate. To overcome the geometrical constraints, we derived an extended essential equation by theoretically considering the effect of refraction. By applying this formula to 3D measurements, the absolute scale of an object could be obtained. However, this method was verified only by a simulation under ideal conditions, for example, by not taking into account real phenomena such as noise or occlusion, which are necessarily caused in actual measurements. In this study, to robustly apply this method to an actual measurement with real images, we introduced a novel bundle adjustment method based on the refraction effect. This optimization technique can reduce the 3D reconstruction errors caused by measurement noise in actual scenes. In particular, we propose a new error function considering the effect of refraction. By minimizing the value of this error function, accurate 3D reconstruction results can be obtained. To evaluate the effectiveness of the proposed method, experiments using both simulations and real images were conducted. The results of the simulation show that the proposed method is theoretically accurate. The results of the experiments using real images show that the proposed method is effective for real 3D measurements.

CROWD-SOURCED VISUAL DATA COLLECTION FOR MONITORING INDOOR CONSTRUCTION IN 3D

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Fouad Amer ◽  
Mani Golparvar-Fard
Keyword(s):  
Data Collection ◽  
3D Reconstruction ◽  
Structure From Motion ◽  
Reconstruction Algorithm ◽  
Point Clouds ◽  
Reconstruction Method ◽  
Visual Data ◽  
Mapping Algorithm ◽  
3D Point Clouds ◽  
Localization And Mapping

Complete and accurate 3D monitoring of indoor construction progress using visual data is challenging. It requires (a) capturing a large number of overlapping images, which is time-consuming and labor-intensive to collect, and (b) processing using Structure from Motion (SfM) algorithms, which can be computationally expensive. To address these inefficiencies, this paper proposes a hybrid SfM-SLAM 3D reconstruction algorithm along with a decentralized data collection workflow to map indoor construction work locations in 3D and any desired frequency. The hybrid 3D reconstruction method is composed of a pipeline of Structure from Motion (SfM) coupled with Multi-View Stereo (MVS) to generate 3D point clouds and a SLAM (Simultaneous Localization and Mapping) algorithm to register the separately formed models together. Our SfM and SLAM pipelines are built on binary Oriented FAST and Rotated BRIEF (ORB) descriptors to tightly couple these two separate reconstruction workflows and enable fast computation. To elaborate the data capture workflow and validate the proposed method, a case study was conducted on a real-world construction site. Compared to state-of-the-art methods, our preliminary results show a decrease in both registration error and processing time, demonstrating the potential of using daily images captured by different trades coupled with weekly walkthrough videos captured by a field engineer for complete 3D visual monitoring of indoor construction operations.

scholarly journals Structural analysis of clastic dikes based on Structure from Motion/Multi-View Stereo

2018 ◽  
Author(s):  
Carlos H Grohmann ◽  
Camila D Viana ◽  
Mariana TS Busarello ◽  
Guilherme PB Garcia
Keyword(s):  
Structural Analysis ◽  
Structure From Motion ◽  
Low Cost ◽  
Three Dimensional ◽  
Fine Sand ◽  
Bundle Adjustment ◽  
Three Dimensional Model ◽  
Focal Distance ◽  
Camera Orientation ◽  
Camera Position

This work presents the development of a three-dimensional model of an outcrop of the Corumbataí Formation using Structure from Motion and Multi-View Stereo (SfM-MVS) techniques in order to provide a structural analysis of clastic dikes cutting through siltstone layers. Composed mainly of fine sand and silt, these dikes are formed by sand intrusions when a wet sandy layer is affected by earthquakes of at least 6.5 magnitude, being used as a record of such events.While traditional photogrammetry requires the user to input a series of parameters related to the camera orientation and its characteristics (such as focal distance), in SfM-MVS the scene geometry, camera position and orientations are automatically determined by a bundle adjustment, an iterative procedure based on a set of overlapping images. It is considered a low-cost technique in both hardware and software, also being able to provide point density and accuracy on par to the ones obtained with terrestrial laser scanner.The results acquired on this research have a good agreement with previous works, yielding a NNW main orientation for the dikes measured in the field and on the 3D model. The development of this work showed that SfM-MVS use and practice on geosciences still needs more studies on the optimization of the involved parameters (such as camera orientation, image overlap and angle of illumination), which, when accomplished, will result in less processing time and more accurate models.

The Association of Stock Distribution Announcements and Earnings Performance

1988 ◽  
Vol 3 (2) ◽  
pp. 113-132 ◽  
Author(s):  
David T. Doran ◽  
Robert Nachtmann
Keyword(s):  
Forecast Error ◽  
Control Sample ◽  
Earnings Forecasts ◽  
Earnings Expectations ◽  
Future Earnings ◽  
Earnings Information ◽  
Unexpected Earnings ◽  
Large Measurement ◽  
Stock Dividends ◽  
Large Measurement Error

This paper analyzes the association of unexpected earnings with stock dividend and stock split announcements. Unexpected earnings are modeled as the percentage deviation of actual earnings from expected. Value Line's earnings forecasts are used as a surrogate for the market's timely expectation of future earnings. The primary findings are: (1) postdistribution earnings realizations are greater than expected; and (2) deviations of realized earnings from expected are (a) directly related to the size of the stock distribution and (b) inversely related to the level of market anticipation of the event. Further, distribution size may be a proxy for market anticipation in that small distributions (stock dividends) are dominated by anticipated events and large distributions (stock splits) by unanticipated events. These findings are robust across samples that control for large measurement error due to small levels of forecasted earnings, and event contamination due to the simultaneous announcement of firm-related events. Examination of analysts' forecasts immediately following the event indicates a significant upward revision in earnings expectations. This finding, coupled with an analysis of a control sample of Value Line earnings forecasts, indicates that the observed unexpected earnings are not the result of systematic Value Line forecast error. Therefore, the paper provides support for the notion that stock distribution announcements convey future earnings information.

Improving the method for determining the dust penetration of textile materials for the human protective equipment manufacture

2020 ◽  
Vol 2 (102) ◽  
pp. 49-54
Author(s):  
A.A. Avahumian ◽  
N.M. Zashchepkina
Keyword(s):  
Road Dust ◽  
Test Sample ◽  
Measuring System ◽  
Negative Effects ◽  
Textile Materials ◽  
Information Measuring ◽  
Information Measuring System ◽  
Large Measurement ◽  
Accuracy Of Measurement ◽  
Large Measurement Error

Purpose: Improving the accuracy of determining the coefficient of dust permeability of textile materials and protective products from them. Design/methodology/approach: The problem solution of human protection from the negative effects of road dust is to improve the quality control procedures of textile materials using modern measurement methods. A methodology has been developed for investigating the dust penetration coefficient of materials based on the use of a television informationmeasuring system (TIMS). Findings: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved, by increasing the accuracy of measurement and determining the patterns of the influence of structure on the permeability of textile materials. Research limitations/implications: Improving methods of quality control of textile materials through the use of modern methods of measuring techniques is by solving an important problem of human protection from the negative effects of road dust. Known methods do not take into account the forceful effect of the airflow on the structure of the test sample, which is essential for textile materials that are easily deformed, which affects the objectivity of the results. Significant inconvenience, complexity, and duration of the test process give a large measurement error. Practical implications: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved. This system allows an increase in the accuracy of measurements by 15%, and the availability of software to increase the speed of displaying the results of investigations on the screen. Originality/value: The main disadvantages of methods and means of determining the dust permeability of textile materials - is the inability to determine the duration and dynamics of the process of dust retention. Known methods do not take into account the force of air flow on the structure of the test sample, which is significant, especially for materials that are easily deformed, which affects the objectivity of the results. Significant inconveniences, complexity and duration of the test process give a large measurement error. A scientific novelty is the development of a modern and completely new method for determining the permeability of textile materials using a television information - measuring system, by increasing the accuracy of measurement and determining the patterns of influence of the structure of textile materials on dust permeability.

scholarly journals Microscopic Structure from Motion (SfM) for Microscale 3D Surface Reconstruction

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5599
Author(s):  
Dugan Um ◽  
Sangsoo Lee
Keyword(s):  
Surface Reconstruction ◽  
Structure From Motion ◽  
Imaging Technique ◽  
Confocal Imaging ◽  
Reconstruction Method ◽  
Accuracy Analysis ◽  
Ambient Light ◽  
Solid Objects ◽  
Transparent Objects ◽  
Novel Method

In microscale photogrammetry, the confocal microscopic imaging technique has been the dominant trend. Unlike the confocal imaging mostly for transparent objects, we propose a novel method to construct a 3D shape in microscale for various micro-sized solid objects in a broad spectrµm of applications. Recently, the structure from motion (SfM) demonstrated reliable 3D reconstruction capability for macroscale objects. In this paper, we discuss the results of a novel micro-surface reconstruction method using the Structure from Motion in microscale. The proposed micro SfM technique utilizes the photometric stereovision via microscopic photogrammetry. The main challenges lie in the scanning methodology, ambient light control, and light conditioning for microscale object photography. Experimental results of the microscale SfM, as well as the modeling accuracy analysis of a reconstructed micro-object, are shared in the paper.

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