Paintings mixing system for plastic arts

Presented by: Ángela Patricia Hoyos GómezDirector: Carlos Alberto Parra Rodríguez, Electronics Engineer, PHDCollaborators: César Bustacara, Martha Manriqueand Juan Daniel Hernández Vega, Engineers.

Bachelor’s degree on Electronics Engineering final term projectSchool of Engineering, Javeriana University

Historical background about

color and technology in the field of plastic arts

Harold Cohen, former director of the CRCA at Stanford University and Aaron, his“painting-robot”

Block diagram of the system developed

Color sensor

Analysis of the color sample using Matlab-Lingo

Percentage of primary colors in the sample

hue, saturation and intensity values of the sample

Electro-mechanical systemof mixing paintings

in the three primary colors

Input : color sample selected from a virtual catalogue

16 secondary colorsand 11 thirds colors

Input : random color sample

Output: 20 ml of the painting in the same color

of the input

Methodology used Methodology used and development of the systemand development of the system

The type of painting chosen for the system

‘Ecolín’Liquid watercolor

brand

Low viscosity

Low cost $5600 per bottle of 500 cc

Easy to clean

Limitations: •To be used with watercolor paper, or cardboard•Transparency characteristicsOther possible choices:

Positive aspects of using watercolors:

primary colors CMY found

Acrylic, Gouache ,oils ,different pigments, and solvents

The HSI model related to

a traditional method of mixing paintings

2

12

1

))(()(

)()(2

1

cosBGBRGR

BRGRH

),,min()(

31 BGR

BGRS

)(3

1BGRI

Color Magenta(%) Yellow(%) red 50 50 n1 40 60 n2 30 70 n3 20 80 n4 10 90

Color Cyan (%) Yellow(%) yw 0 100 g1 10 90 g2 20 80 g3 30 70 g4 40 60

Color Cyan (%) Yellow(%) green 0 100 g5 10 90

g6 20 80 g7 30 70

g8 40 60

Color Magenta(%) Yellow(%)magta 100 0

n5 90 10n6 80 20n7 70 30n8 60 40

Color Cyan (%) Magenta(%)cyan 100 0

b1 90 10b2 80 20b3 70 30b4 60 40

Color Cyan (%) Magenta(%)blue 50 50

b5 40 60b6 30 70b7 20 80b8 10 90

Secondary colors

Numeric method of mixing paintings: Concentrations varying from 10% to 10%

Color Mapping of the samples

Detection of signals: A regular distribution of the reference signals

and other signals close to these references

The visible spectrum:Irregular distribution of the colors

in the spectrum

Color samples identification:Polygonal areas of different sizes

between the reference colors

Establishing relationships between colors

Possible development of the mixing system

Using timers and controlling the flowof the watercolor painting

Dosing system implementedtaking in account

the number of pulses discharged of each color

Using pneumatic systems

Hardware of the system implemented

PIC MicrocontrollerValves

& Pneumatic cylinders

Two 8 bits words with information about the

percentages of C,M,Y to be mixed

On/Off control signalsof the electromechanical system

Serial Tx

Feedback signals of the movement of the cylinders

Check valve

Body of the valve

Gates

Checks

Conclusions: results and initial goals

•Numerical analysis method

Initial goal, studying 16 colors => finally 48 samples of color were studied

+ A random sample of color could be mapped on the HSI color space=> This color space offers a more human perception of color than the RGB color space.

•The electromechanical system was fully developed

Precision was reached using the counting pulses method. It allows the system to extend the number of colors to be prepared. Financial costs were reduced by the design of the check valve and the use of pneumatic elements.

New questions and possible future developments

SWR and HWR: Implementing color analysis and the electromechanical system for quality control, in paintings related industries lacking of it,in Colombia - i.e Roseta Co. , IMA S.A

Research on color theory: Cross-disciplinary research group (Physics, Arts, Engineering, Medicine Schools)

References

Color chapters of booksabout image processingwww.handprint.com

Bibliographyof the course ‘Color’ of the Visual Arts Department

the world's finest guideto watercolor painting

Bruce McEvoy

PUJ Industrial Automation Technological Center

PUJ

¡Thank you!