SAMBA

From specular to diffuse light,
revisit the way you observe the world

Samba polarization camera

Overview

SAMBA is a polarization-difference digital camera. Compact and robust, SAMBA has all the attributes of a regular digital video camera (easy operation, point & shoot, USB3 connection) plus the polarization analysis capability.

Polarization difference camera is mainly used in ACTIVE imaging configuration, where the scene is illuminated by a controlled source. Measurement with SAMBA requires a totally polarized illumination in order to take full advantage of its performances.

Coupled with a dedicated software, SAMBA allows the analysis of the scattering properties of objects. It is designed for the measurement of the gloss of textured objects with complex 3D shape and can be used as an imaging glossmeter. SAMBA delivers gloss degree images related to the human visual assessment and gloss images related to the surface quality. Its field of applications is very wide and ranges from cosmetic testing (skin, hair, lips, nails, …) to gloss measurement of industrial parts (water and oil detection, roughness assessment …).

Principle

Polarization-difference imaging is explained below, in the case of active imaging. The observed scene is illuminated by a controlled source with a known polarization state. In the example below, it is a horizontal linear polarization state. The incident light is scattered by the object. The light collected by SAMBA carries both polarization states P (Parallel) and C (Crossed). SAMBA camera successively acquires the polarization states P and C for each pixel of the image, at video rate.

Example of images observed depending on structural surface quality

Rough surface (left) to Smooth surface (right)

SAMBA measures the depolarization of the polarized illumination for each pixel of the image. The acquisition of the 2 polarization images, P and C allows the calculation of various parameters for each pixels of the image:

Image Formula
Specular (S)
S = P - C
Diffuse (D)
D = 2 x C
Intensity (I)
I = S + D = P + C
Degree of Linear Polarization (DOLP)
DOLP = S/I = P-C/(P+C)

Those polarization images contain numerous information about the observed scene. S is the specular image i.e. the image generated only by the light coming from the object surface. D is the diffuse image i.e. the image generated only by the light coming form the sub-surface/volume of the object. DOP is related to the gloss of the object (ratio specular/intensity).

SAMBA can also be used in passive imaging, where the illumination is not controlled. SAMBA will detect the polarization of an un-polarized illumination (specular reflection for example). For more information about that application, please contact us.

Technology

SAMBA is a polarization-difference digital camera based on a fast polarization analysis. The polarization switch from parallel to crossed analysis is electrically driven which allows a fast and reliable analysis (no rotating polarization elements). Our proprietary polarization difference analyzer allows polarization difference imaging at high frame rate (up to 10,000 frame/s).

SAMBA Camera Difference presentation technology concept

The polarization rotation switches from no rotation (state 1) to 90 degree rotation (state 2) at video rate, allowing the successive transmission of the vertical and horizontal linear polarization state. Our unique polarization difference analyzer SAMBA can be used with a complete line of C-mount or F-mount lens.

A contrast ratio (CR = P/C) of more than 300 can be achieved over the full visible bandwidth (400 nm to 700 nm).

Specifications

SAMBA specifications are summarized in the following table :
SPECIFICATIONS
Camera body size
(without lens)
Cylinder:
h= 90mm
r = 25mm
Weight
< 0.3kg
Resolution (pixels)
1,024 x 1,024
1,600 x 1,200
1,920 x 1,080
2,500 x 1,900
Frame rate
From 3 to 70 frame per second
Optical size
1/1.8“ to 1/3.7”
Bit depth
8 to 12 bits
Spectral bandwidth
400-700 nm
Data output type
USB 3.0, nominal max. 5 Gbit/s
Polarization contrast ratio
> 200
Lens mount
C-mount
(contact us for other options)
Software
SAMBA Polarization Imaging 2.0
We also propose a SAMBA working in the near infrared (750 nm – 830 nm). Contact us for more details.

* Due to Bossa Nova Vision continuous improvement policy, specifications are subject to change without notice.

Resources

SAMBA resources include literature (articles & application notes) and videos to download.