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Linea SWIR GigE Camera Quick Start Guide 

 

3  

 

 

Teledyne DALSA   

03-032-20284-02  

 

•

 

You can now stop the grab, add a lens and adjust other camera parameters—such as Line Rate, Exposure 

time, etc. to develop your imaging application.  

•

 

Refer to the camera’s user’s manual for a description of all of the available camera commands.  

Flat Field Correction Overview 

The Flat Field Correction function (FFC) uses two coefficients per pixel to correct the gain and offset of the 

corresponding pixel. These corrections compensate for Photo-Response Non-uniformity (PRNU) and Fix 

Pattern Noise (FPN) unique to each camera sensor.  

 

Note: it is important that you perform the FFC calibration under the same conditions the camera will be used 

in.  

 

Before calibration, the camera should be powered on long enough to achieve its nominal temperature. The 

exposure time and camera internal temperature need to be similar to the expected operating conditions—

otherwise, image sensor variations (over temperature and exposure) will render the FFC calibration invalid.  

 

The current camera version supports an FFC calibration through Sapera CamExpert, while the FFC correction 

is done in the camera device. 

 

The following is a brief overview of the main calibration steps for users already familiar with the Flat Field 

Correction. 

Содержание Linea SWIR GigE

Страница 1: ...tside of their intended wavelength range There are several manufacturers that make C mount SWIR lenses specifically for machine vision systems For assistance in selecting suitable optics for your application please contact one of our regional sales offices Connect the Linea SWIR GigE Camera Before connecting power to the camera test the power supplies The camera requires a single voltage input Min...

Страница 2: ...icking the desktop icon created during the Sapera LT installation If using a different software application then follow the specific instructions for your application CamExpert will search for installed Sapera devices The connected Linea SWIR GigE camera should be listed in the Device window on the left side of the app once CamExpert completes the automatic device search device discovery Select th...

Страница 3: ... PRNU and Fix Pattern Noise FPN unique to each camera sensor Note it is important that you perform the FFC calibration under the same conditions the camera will be used in Before calibration the camera should be powered on long enough to achieve its nominal temperature The exposure time and camera internal temperature need to be similar to the expected operating conditions otherwise image sensor v...

Страница 4: ...model 512 x 1 pixels verify in the Image Format Controls section that the Horizontal and Vertical binning are set to 1 and that the image Width is set to 1024 or 512 for the 512 model as shown here Before performing an FFC we strongly recommend that you evaluate the bare image characteristics The bare image quality determines the quality of FFC that will be applied to the image To obtain a bare im...

Страница 5: ...evaluate a bare image The following line profile is an example of the bare image of a white uniform object Make sure that the average output level is set close to your calibration target An extremely low output will increase the noise level significantly high after the PRNU is corrected such that the SNR and or DNR may not meet your application s requirements ...

Страница 6: ...ibration will average out any dirt or texture present Set up Black and Bright Acquisitions with the Histogram Tool Verify the camera s acquisition with a live grab and prepare to grab a flat light gray image required for calibration Ideally a controlled diffused light source aimed directly at the lens should be used or a non glossy paper with the lens slightly out of focus or evenly lite wall Note...

Страница 7: ... to adjust for a bright gray approximately pixel value 200 for 8 bit pixels The following figure displays a histogram while grabbing a bright gray image Important In this example the average pixel value for the frame is bright gray Note Sensors may show a much higher maximum or a much lower minimum pixel value due to one or more hot or dead pixels The sensor specification accounts for a small numb...

Страница 8: ... uniformity corrections NOTE Before performing a FFC we recommend you evaluate the bare image characteristics which determine the quality of FFC applied to the image To obtain a bare image disable FPN and PRNU coefficients Choose Off from Flat Field Correction Mode 1 Setting gain to 1x Type or use the numeric up down control to set the value to 1 0 as seen below 2 Choose Off from Flat Field Correc...

Страница 9: ...Linea SWIR GigE Camera Quick Start Guide 9 Teledyne DALSA 03 032 20284 02 To evaluate a bare image use the line profile tool shown below Line Profile Example ...

Страница 10: ...d or DNR not meeting your application requirements the profile should reach a level near the calibration target NOTE Changes to gain do not improve image quality from a SNR perspective Gains are analog and digital multipliers that scale up signal and noise proportionally Before performing a FFC keep the following in mind Ensure the camera s temperature is at nominal operating condition Power on fo...

Страница 11: ...elect Calibration from Flat Field Correction Mode drop down menu Step 4 Select 2048 or 4096 option from Flat Field Calibration Sample Size The 2048 option reduces calculating time 4096 option returns result that is more accurate Step 5 Press the Press command in the Calibrate FPN menu ...

Страница 12: ...ommon ways to correct the grain effect are 1 Target in motion while PRNU Correction is performed 2 Defocus lens while PRNU Correction is performed Select Off from Flat Field Correction Mode drop down menu and check the bare image line profile Step 2 Select Calibration from Flat Field Correction Mode drop down menu Step 3 Adjust the calibration target in the Flat Field Calibration Target in DN if n...

Страница 13: ...urrent Active Set Press the Press command in Save Calibration menu to Active the Set If not saved the FFC result will be lost when the Active Set or Calibration mode is changed Step 7 Select Active from Flat Field Correction Mode drop down menu to apply the calibrated FPN and PRNU parameters Refer to the figure below to verify the line profile ...

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