SAMBA HAIR SYSTEM - HAIR VISUAL APPEARANCE CHARACTERIZATION- 2009 presentation (english).pdf ·...

SAMBA HAIR SYSTEM

- HAIR VISUAL APPEARANCE CHARACTERIZATION-

N. Lechocinski，，，，M. Ikeda, P. Clemenceau, S. Breugnot

Bossa Nova Technologies, Venice, CA, USA

CITE Tokyo, March 09

• Bossa Nova Technologies company profile

• Technical background :

• Polarization, Interaction between light and sample, Hair visual appearance

• Hair measurement setup :

• Setup, Images acquired, Angular profiles

• Luster parameter

• Usual luster formulae, issue with polarization, new luster formula

• Experimental results

• On black, red and blond hair

• Color analysis allows full understanding of light scattering

• Comparison with goniophotometry

• Video

• Conclusion

Table of contents

� LLC Created in 2002. Located in California, USA

� Team of engineers and scientists specialized in optics, electronics, imaging and software development

� Bossa Nova Technologies manufactures sensors, non destructive testing systems, and visual appearance measurement systems

SAMBA

Face System

Systems for the cosmetic industry

Company profile

SAMBA

Hair System

Light can be characterized by three fundamental properties :

• its intensity

• its spectrum (visible spectrum (color), also infrared, UV, …) • its polarization

Related to amplitude of light vibration

Related to frequency/wavelength of light vibration

Related to orientation of light vibration

Technical background: Polarization of light

Vertical Polarizer

SPECULAR

Sample (Skin, hair…) Pigments

DIFFUSED/SCATTERED LIGHT

Polarization is preserved

Depolarized Light

Light source

Technical background: light scattering

Polarization is a tool to study light scattering.

It allows to separate reflections (specular light) from diffusion.

We use it to characterize the visual appearance of hair.

Technical background: interaction of light with hair fibers

Shine= White band coming from the

reflection on the surface

Chroma= Colored band coming from the internal

reflection

Diffused light: uniform background color coming from internal scattering

POLARIZED

UNPOLARIZED

Visual appearance of hair can be measured by measuring the light scattering

The setup used is based on three main elements:

• A polarized illumination (2)

• A cylinder on which the sample is positioned (3)

• A polarization camera (1)

Polarized illumination and polarization camera allow

measuring independently reflections and diffusion.

Cylinder is used to record angular distribution profiles

The cylinder also reproduces the human head curvature

Hair System setup

SAMBA Hair System is a visual setup based on polarization imaging

Each section on the image corresponds to an angle of incidence on the cylinder.

Using a cylinder allows recording all angles on a single image, without moving the cylinder.

This is a visual setup.

Hair System setup

Diffused image

(internal scattering)

Diffused light and reflections are physically separated without using fits or mathematical decomposition.

As reflections are responsible of the luster sensation, polarization is a useful tool to help quantify luster.

Polarization imaging physically separates reflections from diffusion on a complete hair tress in just seconds.

Intensity image

(seen by the eye)

Specular image

(reflections only)

= +

Acquisition of the images (data)

0

10

20

30

40

50

-45 -30 -15 0 15 30 45

Angle (deg)

No

rma

liz

ed

un

its

L

R

G

B

0

1

2

3

4

5

6

-45 -30 -15 0 15 30 45

Angle (deg)

No

rma

liz

ed

un

its

L

R

G

B

Averaging along the hair tress

From the images to the profiles and numerical data

Cross sections

Specular image Diffused image

Specular angular distributions (Luminance and color)

Diffused angular distributions (Luminance and color)

Characterization of the profiles with numerical

parameters such as maxima, integrals and width

LUSTER

Luster sensation is considered to depend on 3 main parameters:

Luster qualifies the visual appearance of the object.

Luster is strongly linked to the idea of quality and beauty of an object.

Scientists have tried to compute a parameter that would quantify the visual luster sensation.

The amount of reflected light

The sharpness of the reflection

The background on which the reflection is observed

The more reflected light there is, the higher the

luster is

The sharper the reflection is, the higher the luster is

The darker the background is, the higher

the luster is

Luster parameter

Higherluster

Higherluster

Higherluster

Usual Luster formulae

These formulae were designed with a mathematical separation of specular and diffused light (curve fitting and other method).

They can be used with the physical separation of diffused and specular lightdistribution with polarization.

Several Luster formulae have been developed and published by scientists using goniometers and other instruments to tentatively quantify human perception of Luster.

The parameters used in the formulae are :

• S the total amount of the specular light

• D the total amount of the diffused light

• θθθθ1/2 the width of the specular light distribution

The 4 most used formulae are:

S

DSLStamm

−−−−====

2/1

Re*θθθθD

SL Robbinsich ====

−−−−

2/1θθθθ

θθθθ ref

TRIDS

SL

++++====

D

SLGuiolet ====

Examples of luster formulae


Bossa Nova Technologies luster:

New formula adapted to polarization imaging

Using the existing formulae with polarization imaging does not always gives a good correlation with visual assessment (especially for dark hair).

We developed a formula that is adapted to polarization imaging.

It gives more dynamic range and better-correlated measurements.

It works on every type of hair and especially on dark samples where other formula tended to lack sensitivity.

visualout

inBNT

WSD

SL

*)( ++++====

Small visual width

large angular width

Presented at the TRI conference in 2008.

Article to come in the Journal of Cosmetic Science

Black hair

+ 116.1 % + 26.8 % + 15.5 %

Bossa Nova TechnologiesTRIReich-Robbins

Black Hair

0

5

10

15

20

25

30

-45 -30 -15 0 15 30 45

Angle (deg)

Specular Light Untreated

Diffused Light Untreated

Specular Light Treated

Diffused Light Treated

Re

fle

cta

nce

(Arb

itra

ry U

nit

s)

Experimental results: black hair

Red hair

+ 84.5 % + 33.5 % + 62.7 %


Red Hair

0

5

10

15

20

25

30

35

40

-45 -30 -15 0 15 30 45

Angle (deg)





Re

fle

cta

nc

e

(Arb

itra

ry U

nit

s)

Experimental results: red hair

+ 109.5 % + 43.7 % + 80.1 %


Blond Hair

0

5

10

15

20

25

30

35

40

45

50

-45 -30 -15 0 15 30 45

Angle (deg)





Re

fle

cta

nce

(Arb

itra

ry U

nit

s)

Experimental results: blond hair


Color analysis allows further understanding

Mathematical algorithm based on color information

(Assuming that shine is white)

Color analysis allows a full decomposition of light scattering in hair fibers

Images calculated from profiles

New research focused on internal reflection ?

New lusters taking into account chroma?

Intensity

Shine

Chroma

Diffused

Intensity= Shine + Chroma + Diffused

intensity

Color analysis allows further understanding

Dark Bright

• On untreated healthy hair, the shine (surface reflection) is comparable for all samples

• As the hair becomes brighter, the chroma (internal reflection) increases as well as the diffused light

• Chroma and diffused (carrying color information) play an important part on the visual appearance

Black Brown Red Blond

The internal reflection (chroma) plays a big part in the visual appearance of hair

Comparison with goniophotometer

Visual (verifiable with the eye)Black boxSet-up

• No Mathematical fit

• Physical extraction of diffuse component using polarization

• Physical separation of shine-chroma using color analysis

Use of mathematical fits and strong assumptions to

separate shine-chroma-diffuse components

Shine-Chroma-Diffuse

components separation

• On real tresses

• All angles in one shot

• Slow

• On single fiber (or a few)

• 1 angle at a time

Measurementprocess

Angular Profiles + ImagesAngular Profiles onlyData

SAMBASAMBASAMBASAMBA HAIR SYSTEMGONIOPHOTOMETER

Conclusion

• SAMBA HAIR SYSTEM is a cutting-edge instrument that objectively quantifies visual appearance of hair

• It uses a visual configuration (measurement verifiable with the human eye)

• Easy to operate (one button operation, seconds for a measurements)

• Well-known luster formulae are calculated in seconds on a complete hair tress

• The system offers numerical data as well as images

• A new BNT luster formula was developed to adapt to measurements made with polarization imaging

• A powerful color analysis allows to fully understand light scattering on all types of hair.

• SAMBA HAIR SYSTEM provides a new physical analysis of the internal reflection (chroma). New research should be conducted to evaluate the importance of chroma, leading to new lusterstaking into account chroma in the formula.

• A great tool widely used in the cosmetic industry to evaluate product efficacy, improve formulations and substantiate claims.

Thank you

Come see us on boothＨ-06(タレスレーザー株式会社)

(Live demo of SAMBA Hair and Face systems)

Tel. 310 577 8114Email:

[email protected]

Bossa Nova Technologies606 Venice Blvd, Suite BVenice, CA 90291 USA

タレスレーザータレスレーザータレスレーザータレスレーザー株式会社株式会社株式会社株式会社東京都大田区大森北東京都大田区大森北東京都大田区大森北東京都大田区大森北2-16-4大阪府吹田市広芝町大阪府吹田市広芝町大阪府吹田市広芝町大阪府吹田市広芝町9-12

Tel. 03-5753-4541（（（（東京東京東京東京））））Tel. 06-6192-7111（（（（大阪大阪大阪大阪））））[email protected]

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