Handheld Color Scanner Presented by David Harwood Project Advisor: John Spinelli “True Colors”
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Transcript of Handheld Color Scanner Presented by David Harwood Project Advisor: John Spinelli “True Colors”
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?