scholarly journals Reconstructing Three-Dimensional Human Poses: A Combined Approach of Iterative Calculation on Skeleton Model and Conformal Geometric Algebra

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 301 ◽  
Author(s):  
Xin Huang ◽  
Lei Gao
Keyword(s):  
High Precision ◽  
Geometric Algebra ◽  
High Performance ◽  
Three Dimensional ◽  
Conformal Geometric Algebra ◽  
Human Model ◽  
Skeleton Model ◽  
New Approach ◽  
Iterative Calculation ◽  
Human Pose

Reconstructing three-dimensional (3D) human poses is an essential step in human bodyanimation. The purpose of this paper is to fill the gap in virtual reality research by reconstructingpostures in a high-precision human model. This paper presents a new approach for 3D human posereconstruction based on the iterative calculation of a skeleton model and conformal geometric algebra,captured by a monocular camera. By introducing the strip information of clothes and prior data ofdifferent human limbs, the location of joint points on the human body will not be affected by theocclusion problem. We then calculate the 3D coordinates of joint points based on the proposed methodof the iterative calculation of the skeleton model, which can solve the high-cost problem caused by theneed for multiple cameras or a depth camera. Subsequently, we utilize high-performance conformalgeometric algebra (CGA) in relation to rotation transformations in order to improve the adjustmentof the postures of the human limbs. Finally, realistic 3D human poses are reconstructed—specifically,the motion of the human limbs—using a rigid transformation of CGA and a smooth connection ofthe limb parts based on a high-precision model. Compared with the existing methods, the proposedapproach can obtain satisfactory and realistic 3D human pose estimation results using grid models.

Differential and inverse kinematics of robot devices using conformal geometric algebra

Robotica ◽  
2006 ◽  
Vol 25 (1) ◽  
pp. 43-61 ◽  
Author(s):  
Eduardo Bayro-Corrochano ◽  
Julio Zamora-Esquivel
Keyword(s):  
Stereo Vision ◽  
Geometric Algebra ◽  
Inverse Kinematics ◽  
Three Dimensional ◽  
Conformal Geometric Algebra ◽  
Robot Arm ◽  
Standard Formulation ◽  
Visually Guided ◽  
Interesting Application ◽  
Differential Control

In this paper, the authors use the conformal geometric algebra in robotics. This paper computes the inverse kinematics of a robot arm and the differential kinematics of a pan–tilt unit using a language of spheres showing how we can simplify the complexity of the computations.This work introduces a new geometric Jacobian in terms of bivectors, which is by far more effective in its representation as the standard Jacobian because its derivation is done in terms of the projections of the involved points onto the line axes. Furthermore, unlike the standard formulation, our Jacobian can be used for any kind of robot joints.In this framework, we deal with various tasks of three-dimensional (3D) object manipulation, which is assisted by stereo-vision. All these computations are carried out using real images captured by a robot binocular head, and the manipulation is done by a five degree of freedom (DOF) robot arm mounted on a mobile robot. In addition to this, we show a very interesting application of the geometric Jacobian for differential control of the binocular head. We strongly believe that the framework of conformal geometric algebra can generally be of great advantage for visually guided robotics.

Meso-Molding Three-Dimensional Macroporous Perovskites: A New Approach to Generate High-Performance Nanohybrid Catalysts

2016 ◽  
Vol 8 (4) ◽  
pp. 2457-2463 ◽  
Author(s):  
Hamidreza Arandiyan ◽  
Jason Scott ◽  
Yuan Wang ◽  
Hongxing Dai ◽  
Hongyu Sun ◽  
...  
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
New Approach

Assembly Guidelines for High Performance Meso-Flexure Linkage Mechanisms

2011 ◽  
Author(s):  
Prasanna Gandhi ◽  
Vaibhav Soni ◽  
Kaustubh Sonawale ◽  
Naved Patanwala
Keyword(s):  
High Precision ◽  
High Performance ◽  
Three Dimensional ◽  
Internal Stresses ◽  
Simple Formulation ◽  
Flexure Mechanism ◽  
Design Flexibility ◽  
Multiple Materials ◽  
Precision Motion ◽  
Data Reading

Flexure mechanism systems with ultra-high precision motion are increasingly being used for several applications including micro-measurement, micro/nano manipulation, microfabrication, data reading, writing on CD, and so on. Flexure linkages offer inherent advantages of being frictionless, highly repeatable, and having great design flexibility. Monolithic fabrication of these mechanisms limits use of multiple materials in the system and becomes expensive especially for three dimensional mechanisms. Alternative method of assembling various components of flexure mechanism is considered in this paper. Assembly guidelines for building flexure mechanisms from separately machined components are arrived at. It is found that if each of the fixed ends of the flexure mechanism is located perfectly using two pins, internal stresses are generated in the linkages and their warping does not allow the desired operation. The proposed guidelines which are based on criterion similar to Grubler’s include a very simple formulation to determine number of location pins to be used in assembly. Further guidelines are laid down to determine locations of these pins. Two flexure mechanisms, one planar and other 3D based on double parallelogram flexure linkage mechanisms are fabricated and assembled using these guidelines and found to be working with repeated assembly and disassembly.

A new approach to high-performance flexible supercapacitors: Mesoporous three-dimensional Ni-electrodes

Nano Energy ◽  
2017 ◽  
Vol 39 ◽  
pp. 639-646 ◽  
Author(s):  
Sun-I. Kim ◽  
Ji-Hun Kang ◽  
Sung-Wook Kim ◽  
Ji-Hyun Jang
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
New Approach ◽  
Flexible Supercapacitors

scholarly journals Three-Dimensional Head-Pose Estimation for Smart Iris Recognition from a Calibrated Camera

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Belhassen Akrout ◽  
Sana Fakhfakh
Keyword(s):  
High Performance ◽  
Iris Recognition ◽  
Three Dimensional ◽  
Head Pose Estimation ◽  
Head Pose ◽  
New Approach ◽  
Recognition Systems ◽  
High Level ◽  
The Comparative Study ◽  
Made In

Current research in biometrics aims to develop high-performance tools, which would make it possible to better extract the traits specific to each individual and to grasp their discriminating characteristics. This research is based on high-level analyses of images, captured from the candidate to identify, for a better understanding and interpretation of these signals. Several biometric identification systems exist. The recognition systems based on the iris have many advantages and they are among the most reliable. In this paper, we propose a new approach based on biometric iris authentication. A new scheme was made in this work that consists of calculating a three-dimensional head pose to capture a good iris image from a video sequence which affects the identification results. From this image, we were able to locate the iris and analyse its texture by intelligent use of Meyer wavelets. Our approach was evaluated and approved through two databases CASIA Iris Distance and MiraclHB. The comparative study showed its effectiveness compared to those in the literature.

Improved 3-D reconstruction using stereo computer graphics and multiple tilt EM images

1995 ◽  
Vol 53 ◽  
pp. 630-631
Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang
Keyword(s):  
Computer Graphics ◽  
High Performance ◽  
Transverse Section ◽  
Three Dimensional ◽  
Stereo Pair ◽  
3D Reconstructions ◽  
Video Cameras ◽  
Biological Objects ◽  
Microscope Images ◽  
High Performance Computer

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.

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