Handheld Color Scanner

Presented by David HarwoodProject Advisor: John Spinelli

“True Colors”

Deep Red

Deep Red

Brown

Brown

Deep Red

Deep Red

Medium Red

Brown

Color Vision Deficiency

Finally, there is an answer…

“True Colors”

Physical Design Goals

Portable and concealable Weight < 140g (about 5oz) Length = 120mm (about 4.7in) Height = 60mm (about 2.4in) Width = 30mm (about 1.2in) 5mm measurement area

Usability Minimal controls Point-and-shoot operation

Functional Diagram

camera processor screen

light source

control function

incident

reflecte

d

Processing of Data1. Reflected wavelengths are

acquired

2. Wave characteristics determined• RGB values• Munsell color system

- Value- Hue- Saturation

Processing of Data (Cont’)

• Characteristics compared to color library

• Standardized Munsell chart HSV

• Color name assigned to scanned surface

Hue = 0.050 = red

Hue = 0.250 = yellow

Hue = 0.403 = green

Hue = 0.775 = blue …

dominant color:

REDHue = 0.440

Light Source Boxed encasing with white LED

Controlled environment

Limitations: emission spectrum is blue-light biased

Color Namesfrom Munsell Color System

10 Basic Colors

Red Orange Yellow Yellow-Green Green Blue-Green Blue Purple Red-Purple Brown

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Mod

erat

e R

edR

ed

Ora

nge

Yello

w

Yello

w-g

reen

Gre

en

Blue

-gre

en

Cya

n

Blue

Sky

Blue

Blue

Flo

wer

Purp

le

Mag

enta

Ora

nge-

Yello

w

Sta

nd

ard

ize

d H

ue

sM

ea

sure

d

Hu

es

Standardized vs. Measured Hue Valuesfor Prototype

Hue Sensitivity

Red

-2-

Org Org

-2-

Yel

Yel-

2-

YelG

rn

YelG

rn-2

-G

rn

Grn

-2-

Blu

Grn

Blu

Grn

-2-

Blu

Blu

-2-P

rp

Prp

-2-

Red

Prp

Red

Prp

-2-

Red

0

0.05

0.1

0.15

0.2

0.25

0.3 MunsellMeasured

Dis

tance

Betw

een H

ue V

alu

es

(dim

ensi

onle

ss)

Results  Item

Generated Color Name Correct? Score

1 Maroon Union Sweatshirt RED   1

2 Maroon Track Sweatshirt RED   1

3 Red Liverpool Jersey RED   1

4 Orange Monkey Shirt YELLOW X 0

5 Orange FarPost Shirt ORANGE   1

6 Orange Boxers ORANGE   1

7 Goldenrod Wold Shirt ORANGE ~ 0.5

8 Yellow PotHolder YELLOW-GREEN ~ 0.5

9 Yellow Bowl YELLOW   1

10 Lime-Green Sweatshirt YELLOW X 0

11 Green B&J Shirt GREEN   1

12 Green Austria Shirt BLUE-GREEN ~ 0.5

13 Light Blue Shirt BLUE-GREEN ~ 0.5

14 Dark Blue Shirt BLUE   1

15 Blue Flip-Flop BLUE-GREEN ~ 0.5

16 Purple CD Case PURPLE   1

17 Purple Detergent Cap PURPLE   1

18 Purple Button-Up Shirt PURPLE   1

19 Brown Pants PURPLE X 0

20 Brown Jacket BROWN   1

21 Brown Munich Sweatshirt PURPLE X 0

Explained by Sensitivity

Figure

14.5/21 = 69% accuracy

Goals

provide color label input output time < 3sec easily concealable marketable price < $150.00 appropriate library size

Achievements

Concept proven Provided a reliable color label for

most surfaces Errors between similar colors

Simple color library Minimal costs for prototype

Further Development Light sensor as opposed to digital

camera A to D converter MATLAB C Microprocessor LCD

Find a way to measure color of distant objects

Traffic lights Unreachable items

Focusing lens Sample smaller areas

Resistor values

Questions?