Images for paper

By shooting

2

Sample collection

• Hard/Soft vertical touch

Finger touch position

5

timer

3

BackgroundSubtraction Normalization Simple

HighpassMono Threshold

BackgroundSubtraction Normalization Difference of

Gaussian Threshold

Normalization Difference of Gaussian

Background Subtraction Binary Finger Analysis

Normalization Difference of Gaussian

Background Subtraction Binary Finger Analysis

Normalization ApproximateDoG

Background Subtraction Binary Finger Analysis

4

ImageFusion(Blend)

IR Camera

IR camera

Undistortion

Undistortion

HomoWarp

HomoWarp

ImageFusion

(Stitching)

IR Camera

IR camera

Undistortion

Undistortion

HomoWarp

HomoWarp

5

DetectionModule Verify Next Parameter Set

Generator

DetectionResult

GroundTruth

Error RateParameter Set

Parameter Set

Parameter Set’

6

7

Detection systemSampleset

Training

Parameter Set

Detection Result

GroundTruth

OptimalParameter

Set

8

VerifyNext Parameter Set

Generator

DetectionResult

GroundTruth

Error Rate

9

Detection systemSampleset

Training

Parameter Set

Detection Result

GroundTruth

OptimalParameter Set

VerifyNext Parameter Set

Generator

DetectionResult

GroundTruth

Error Rate

Parameter Set

10

11

12

Detection systemTest set

Optimal parameter finder

Parameter Combination

Detection Result

Optimal Parameter Combination

Ground truth(Trace)

VerifyNext Parameter Set

Generator

DetectionResult

GroundTruth

# of miss & # of false alarm

Parameter Combination

Optimal parameter finder

Applicable Parameters Determinator

Parameter Combination

Detection Result

Applicable set of Parameters

TestSet

Touch Data

Ground truth(Trace)

Detection System

14

frame 1

frame 2

miss frame 1

frame 2

False alarm

miss

15

frame 1

frame 3

frame 2 frame 1

frame 3

frame 2

frame 3False alarm

miss

16

frame 1

frame 1

False alarm

17

Undistortion

18

Dead zone

19

20

ImageStiching

FingerDetection

Finger Tracking

21

Image blend

23

Hardware configuration

• Order of diffuser layer and touch-glass layer

Diffuser layer

IR illuminatorIR camera

spot

IR illuminatorIR camera

Touch-glass layer

IR camera

spot

IR camera

24

Modified by 510

• Order of diffuser layer and touch-glass layer

Diffuser layer

IR illuminatorIR camera

spot

IR illuminatorIR camera

Touch-glass layer

IR camera

spot

IR camera

2

1

4 3

Sampling

Measure

1 1( | )t tP X Z

1( | )t tP X Z

( | )t tP X Z

INITIALIZE PARTICLES

PARTICLE GENERATION

WEIGHT COMPUTATION

1 2 M

1 2 M

NORMALIZE WEIGHTS

More iteration

Over l imited iteration

RESAMPLING

OUTPUTNo

Yes

Yes

No

……

……

PARTICLE GENERATION

WEIGHT COMPUTATION

5 2

16

2 5

43

1

4

3

6

VSLH VS

RH

2

5

5 2

16

2 5

43

1

4

3

6

VSLH VS

RH

2

5

INITIALIZE PARTICLES

Particle Generation

Weight Computation

1 2 M

1 2 M

Normalize Weights

Mo re I te ra t ion

Over

Resampling

OUTPUTNo

Yes

Yes

No

VSLH

(2) IR Camera

(3) IR Illuminator

(1) Peripheral Projector

Optimal Parameter Finder

Finger Detection System

Interface

GPU

Direct3D

HLSL

Dshow

GShow DirectShow

HomoWarp ImageFusion

BackgroundSubtraction Normalization Difference

of Gaussian Binary FingerAnalysis

Multi-touch Finger Detection System

GShow DirectShow

HomoWarp ImageBlending

BackgroundSubtraction Normalization Difference

of Gaussian Binary FingerAnalysis

Multi-touch Finger Detection System

Normalization Difference of Gaussian

Background Subtraction Binary Finger Analysis

Subtract value

Smooth kernel Threshold Finger size

Low bound 0 7 10 15

Step 3 2 3 9

High bound 15 17 25 60

RGBTo Gray

Background Subtraction Normalization Approximate

DoG Threshold

Frame per second 410 385 400 400