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EMVA Standard 1288. Standard for Measurement and Presentation of Specifications for Machine Vision Sensors and Cameras . Agenda. Motivation Goals Approach Current state & Outlook Brief presentation of first released module. Motivation.
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EMVA Standard 1288 Standard for Measurement and Presentation of Specifications for Machine Vision Sensors and Cameras
Agenda • Motivation • Goals • Approach • Current state & Outlook • Brief presentation of first released module
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
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@emva.org
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
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
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
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 time[1] • 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 n+1 can happen at the same time). • Maximum frame rate at the given operation point. (no change of settings permitted) • Others (Interface Type etc..)
Mathematical Model Parameters ParameterIdentification Camera Content of Module 1 Description of Mathematical model
Content of Module 1 Continued • Illumination Setup from Module 1 • Homogenous illumination • Without lens • F-number 8 • Definition of temperature measurements MeasurementSetup
[DN] Image mean [#p~] [DN] sm.temp [#p~] 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
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)
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
The spectrogram method Content of the Module 1 Continued • Compute and plot a row and column FFT of the image at 3 illuminations (dark; 50%saturation; 90% saturation) • Extract spatial noise performance from spectrogram. • Permits to get more insight in FPN and temporal noise performance then bare figures.
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)
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
Thank you for your attention • Current standard draft www.emva.org • Join the working group: info@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@awaiba.com • +351 291 723 124 / +49 4102 457 176 • www.awaiba.com