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Linea SWIR GigE Camera Quick Start Guide 

 

6  

 

 

Teledyne DALSA   

03-032-20284-02  

How to do a FFC Setup  

The process requires images be snapped in black and bright conditions, followed by the FFC process.  

 

If using a sheet as a white target, it must be completely free of blemishes and texture.  

 

Dirt or texture will generate variating in the image and incorporate it into the calibration coefficients of 

the camera. Vertical stripes are visible while imaging after the target is removed. 

 

A moving target during calibration 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 the lens iris position for a bright but 

not saturated image. 

Verify a Black Acquisition 

Close the camera lens iris and cover the lens with the lens cap. Using CamExpert, click on the grab button 

and then select Histogram. The following figure shows a typical histogram for a camera grabbing a dark 

image. 

 

 

 

Summary of Contents for Linea SWIR GigE

Page 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...

Page 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...

Page 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...

Page 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...

Page 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 ...

Page 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...

Page 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...

Page 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...

Page 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 ...

Page 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...

Page 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 ...

Page 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...

Page 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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