controlling a computer by hand gestures · introduction •overview 3 pic from multi-touch -...

Controlling a Computer by hand

gestures

Supervisor: Yuchao Dai, Laurent Kneip, Hongdong Li

Student: Bohuai Jiang u4652552

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Content

• Introduction

• Technique review

• Design and Implementation

• Experiment and Evaluation

• Conclusion and Future works

Introduction

• Overview

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Pic from Multi-touch - Wikipedia, the free encyclopedia. 2014. Multi-

touch - Wikipedia, the free encyclopedia. [ONLINE] Available

at:http://en.wikipedia.org/wiki/Multi-

touch#mediaviewer/File:Multitouch_screen.svg. [Accessed 02

November 2014].

Introduction

• Overview

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Pic from Multi-touch - Wikipedia, the free encyclopedia.

2014. Multi-touch - Wikipedia, the free encyclopedia. [ONLINE]

Available at:http://en.wikipedia.org/wiki/Multi-

touch#mediaviewer/File:Multitouch_screen.svg. [Accessed 02

November 2014].

Introduction

• Overview

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Pics form Geekerific home, controlled by voice and hand

gestures - AGBeat. 2014.Geekerific home, controlled by

voice and hand gestures - AGBeat. [ONLINE] Available

at: http://agbeat.com/tech-news/geekerific-home-controlled-

voice-hand-gestures/. [Accessed 02 November 2014].

Introduction

• Objective– Build a robust and real time human hand pose estimation and

tracking system.

– Data collected form RGB-Depth Camera

– Mainly focused on :

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hand Model construction Cost function computation optimization

3.How to use the RGB-D camera "Asus xtion pro" with ROS. - DASL MediaWiki.

2014. 3.How to use the RGB-D camera "Asus xtion pro" with ROS. - DASL

MediaWiki. [ONLINE] Available

at:http://dasl.mem.drexel.edu/wiki/index.php/3.How_to_use_the_RGB-

D_camera_%22Asus_xtion_pro%22_with_ROS.. [Accessed 02 November 2014].

Technique review

• Iteration Closet Point (ICP)

• Gradient descent

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Technique review

• Iteration closest point (ICP)– Algorithm employed to minimize the difference

between two point clouds by iterations

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Pic from Documentation - Point Cloud Library (PCL). 2014. Documentation - Point Cloud Library (PCL). [ONLINE] Available at:http://pointclouds.org/documentation/tutorials/interactive_icp.php. [Accessed 03 November 2014].

Technique review

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Technique review

• Basic Iteration Closet Point

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Technique review

• Iteration Closet Point in hand tracking and

optimization

– Point-model alignment task

– Require more complex ICP

– Gradient descent base ICP

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Technique review

• Gradient descent

– Widely using for multivariable function

optimization.[1][2][3]

– Easy and simple to be understood

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Gradient descent - Wikipedia, the free encyclopedia. 2014. Gradient descent - Wikipedia, the free encyclopedia. [ONLINE] Available at:http://en.wikipedia.org/wiki/Gradient_descent. [Accessed 03 November 2014].

Technique review

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Image form Tuning the learning rate in Gradient Descent | Datumbox. 2014. Tuning the learning rate in Gradient Descent | Datumbox. [ONLINE] Available at:http://blog.datumbox.com/tuning-the-learning-rate-in-gradient-descent/. [Accessed 03 November 2014].

Technique review

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Design and Implementation

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Design and Implementation

• Model construction

• Cost function

• Gradient-base ICP

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Design and Implementation

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Design and Implementation

• Model – Adopt commonly used 26 degree of freedom model.

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Image form Qian, C., Sun, X., Wei, Y., Tang, X., & Sun, J. Realtime and

Robust Hand Tracking from Depth.2014

Design and Implementation

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Design and Implementation

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Design and Implementation

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Design and Implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

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Design and implementation

• Gradient descent implementation

- Created self-adjust lambda

Time complexity:

O(10*|M|*|sub(P)|)

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Design and implementation• Gradient descent base ICP

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Experiment and Evaluation

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Experiment and Evaluation

• ExperimentGround truth:

• Used from CVPR14 at

http://research.microsoft.com/en-/um/people/yichenw/handtracking/index.html

Goal:

1.Test gradient-descent base ICP performance for last frame

initialization.

2.Test gradient-descent base ICP performance for random

initialization.

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Experiment and Evaluation

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Experiment and Evaluation

• Random initialization.

– Steps:1. Add random noise between −1° 𝑡𝑜 1° to all rotation

variable from DOF26, and Add random value between -1 to

1 to all translation variable from DOF26

2. Run ICP and compute error

3. Increasing random value range. And Repeat step 1 and

step 2.

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Experiment and Evaluation• Result for last frame initialization

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Experiment and Evaluation

• Result for Random initialization

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Conclusion and Future Work

• Conclusion– Gradient descent base ICP is not feasible for hand tracking and

pose estimation.

• It is acceptable to optimize last frame initialization hand model

• Performed poorly on random initialization

– Its performance should be improve using stochastic optimization

such as PSO.

– Gradient descent base ICP has a great potential of

improvements

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Future work

• Replace random selection by other sample techniques,

such as systematic sampling.

• More scalable hand model need to be implemented so

that it can used for general data

• Set constraints to DOF26 to avoid counter-intuitive hand

pose generated by hand model

• implement stochastic optimization to out ICP

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Thanks for listening

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Reference

[1]Li, Z., Chen, J., Chong, A., Yu, Z., & Schraudolph, N. N.. Using stochastic gradient-descent scheme

in appearance model based face tracking. In Multimedia Signal Processing, 2008 IEEE 28 10th

Workshop on (pp. 640-645).in IEEE.2008

[2] Bray, M., Koller-Meier, E., Müller, P., Van Gool, L., & Schraudolph, N. N.. 3D hand tracking by rapid

stochastic gradient descent using a skinning model. In In 1st European Conference on Visual Media

Production in CVMP. 2004

[3] Hou, S., Galata, A., Caillette, F., Thacker, N., & Bromiley, P.. Real-time body tracking using a

gaussian process latent variable model. InComputer Vision, 2007. ICCV 2007. IEEE 11th International

Conference on (pp. 1-8). IEEE. In 2007

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