Optical Multi Touch Technology

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Darshan VithaniME CSE Department,

Parul Institute Of Engineering and Technology

4 October 2013

Optical Multi-touch Technology

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Multi-touch Table


Contents

Introduction to Multi–Touch TechnologyDescription of MT DevicesVarious Sub SystemH/W & S/W Required Usage of Multi-Touch devices


Introduction

Multi-touch technology is an advanced human-computer interaction technique that recogonises multiple touch points and also includes the hardware devices for implement it


DescriptionThe multi-touch device is a user interface device that will allow a user to interact with a computer through use of a multi-touch display.

it is a substitute to the keyboard and mouse

In this user can directly interact with the system with their fingers and not only this but with multiple touches at the same instant.


How Does a Touchscreen Work?

A basic touch-screen has three main components:

Touch sensor; Controller; Software driver.

The touch-screen is an input device, so it needs to be combined with a display and a PC or other device to make a complete touch input system.


Touchscreen Technology

Resistive Capacitive Optical


TERMINOLOGY

Diffuser: Screen surface for projection. IR Lasers: Laser emitting IR Beam. IR Led: Led emitting IR. Blob - A bright luminescent object Blob tracking - Assigning each blob an ID (identifier). TUIO - A protocol used for communicating the position, size, and

relative velocity of blobs. (Tangible User Interface Object) CCV: An open source software for blob tracking. (Community Core

Vision) MT: Multitouch


FTIR :Frustrated Total Internal Reflection DI: Diffused Illumination DSI: Diffused Surface Illumination LED LP: Led Laser Plane LLP: Laser Light Plane

TECHNIQUES


FTIR :Frustrated Total Internal Reflection


Diffused Illumination


Diffused Surface Illumination


LED LP


IR LASER PLANE


BLOCK DIAGRAM OF TABLE


BLOCK DIAGRAM OF WALL


Implementation on Wall


Camera Sensor & IR Bandpass Filter


Input Subsystem: The Camera

We can use a simple web camera that can be easily available in the market.

It can be made capable of detecting IR by simply removing the filter from the lens


Output Subsystem: Projector

We can use a simple web camera that can be easily available in the market.

It can be made capable of detecting IR by simply removing the filter from the lens


Computer Subsystem

A personal computer with 20 GB free hard disk space, 1GB RAM and PIV + processor can be efficient enough.

The Windows XP/7/8 operating system was chosen because the CCV package is highly supported in Windows.

It is also support Mac OS ,linux Debian , Ubuntu & Fedora etc


Application Development

Adobe Flash / Flex / Air Browser & Web (HTML/CSS/Javascript) C/C++ (CCV/OpenCV/OpenGL/OpenFrameworks) Java (Android/Processing.org) C# (.NET/Silverlight/WPF) Objective-C (Cocoa/iPhone)


APPLICATIONS

Personal Computing Advertising Graphics Audio Mixing Video Playing Computer Gaming Slide Presentations……and many more!


CONCLUSION Multi-touch technologies have a long history. Mostly multi Touch devices

have limited resolution, are relatively complex, and don't easily and inexpensively scale up to large dimensions.

Optical Multi-touch technology use FTIR technique that is simple and easy to implement . It provides any resolution displays supported with high graphics.

In this research , it requires a significant amount of space behind the interaction surface. Instead of this we can use Raspberry Pi & its introduction covered by Pranav Pathak.


REFERENCES[1] Low-Cost Multi-Touch Sensing through FTIR by Jefferson Y. Han[2] Buxton, W., Hill, R., and Rowley, P. 1985. Issues and Techniques in [3] Touch-Sensitive Tablet Input[4] Donald Hearn ,M Pauline Baker, Computer Graphics C version, 2/E[5] Pearson Education ,2003 [6] Buxton, Bill. 2008. Multi-Touch Systems that I Have Known and Loved. [7] URL: http://www.billbuxton.com/multitouchOverview.html[8] How to build a multi touch by Harry Vaan Der[9] Opensource,MultitouchDisplay,http://www.technologyreview.com/Infotec[10] OpenCV on the Raspberry Pi , http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=6354

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Thank YouDarshan Vithani, 4 October 2013