EMVA Standard 1288

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EMVA Standard 1288
Standard for Measurement and Presentation of
Specifications for Machine Vision Sensors and
Cameras
2
Agenda

• Motivation
• Goals
• Approach
• Current state Outlook
• Brief presentation of first released module

3
Motivation

• EMVA Standardization Working Group launched in
  February 2004
• Aim is to increase transparency of image sensor
  camera specifications
• Existing standards from broadcasting industry
  not suitable for describing performance of image
  giving systems in machine vision applications
• Well-defined standards will increase
  transparency for customers, prevent unfair
  comparison of specification sheets, reduce
  support time, facilitate selection of the right
  camera or image sensor
• Increase credibility of the industry

4
Participating companies

• The standardization working group is open to all
  who constructively participate
• Apply for registration at www.emva.org or e-mail
  to info_at_emva.org

5
Goals

• Elaborate a recommendation for a specification
  parameter set with clearly defined physical
  definitions of each parameter
• Elaborate a measurement guideline for each of the
  recommended parameters
• Provide information for understanding the
  implication of the recommended parameters to the
  performance of machine vision systems and
  guidelines for conversion of the parameter to
  other definition systems

6
Approach

• Modular standard framework
• New modules are to complete the standard rather
  than to replace previous versions

• Module 1
• Sensitivity
• Quantum efficiency
• Dynamic range
• Spatial and temporal noise
• Over all system gain

• Module 2
• Linearity
• Artifacts
• Defect pixels

• Module 3
• Color

• Module X
• More to follow

The modular approach protects investment in
measurement equipment, processes and education
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Current State

• First Module released in August 2005
• Logo is available at www.EMVA.org
• Full Standard available at www.EMVA.org
• Companies self certify standard compliance

First cameras characterized according to the
standard at vision PCO pco.1600 pco.2000
pco.4000 BASLER A102f A311f A312f A60xf
A631f A641f
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Content of the Standard

• Basic Information
• This section delivers general information and
  information regarding the operation point at
  which data is acquired.
• Vendor name
• Model name
• Type of data presented Typical Guaranteed
  Guaranteed over life time1
• Sensor type (CCD CMOS CID etc...)
• Sensor diagonal in mm Indication of lens
  category to be used inch
• Resolution Pixel size (width x height in µm)
• Readout type (CCD only) Transfer type (CCD
  only)
• Shutter type (CMOS only) Global Rolling
• Overlap capabilities (readout of frame n and
  exposure of frame n1 can happen at the same
  time).
• Maximum frame rate at the given operation point.
  (no change of settings permitted)
• Others (Interface Type etc..)

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Content of Module 1
Description of Mathematical model
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Content of Module 1 Continued
Measurement Setup

• Illumination Setup from Module 1
• Homogenous illumination
• Without lens
• F-number 8
• Definition of temperature measurements

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The photon transfer method
Content of Module 1 Continued

• Acquire series of images at increasing number of
  integrated photons (by variation of the
  integration time)
• Represent mean value and temporal noise over
  photons
• Permits to determine each parameter independently

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The photon transfer method

• Measured Quantities
• Mean of the gray values
• (How much light generates how much signal)
• Variance of the temporal distribution of the gray
  values
• (How much temporal noise do we have at what
  signal level)

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The photon transfer method

• Derived Quantities
• Overall system gain
• (Responsivity of the sensor/camera)
• Total Quantum efficiency
• (QE including FF, glass ML etc..)
• Full well capacity
• (How many electrons are needed for the saturation
  signal)
• Absolute Sensitivity
• (How much light equals the read noise)
• Dynamic input Range

14
The spectrogram method
Content of the Module 1 Continued

• Compute and plot a row and column FFT of the
  image at 3 illuminations (dark 50saturation
  90 saturation)
• Extract spatial noise performance from
  spectrogram.
• Permits to get more insight in FPN and temporal
  noise performance then bare figures.

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The spectrogram method

• Derived Quantities
• Standard deviation of the spatial offset noise
  referenced to electrons in e-.
• (Total FPN at a given light level)
• Standard deviation of the spatial gain noise in
  .
• (Total gain noise PRNU)
• Signal to Noise Ratio
• (SNR including all noise contributions)

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Data Presentation

• Describe data presentation
• Present all data in physical units
• Refer data to photons
• Present raw data and extracted parameters
• Permits the user to check matching of the model
  to the data and pick parameters relevant to their
  application

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Thank you for your attention

• Current standard draft
• www.emva.org
• Join the working group
• info_at_emva.org
• Acknowledgements
• Dr. F. Dirks Dr. G. Holst
• All members of the 1288 Workinggroup

Contact Martin Wäny AWAIBA Lda. Madeira
Technopolo 9020-105 Funchal Madeira
waeny_at_awaiba.com 351 291 723 124 / 49 4102 457
176 www.awaiba.com