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CamExpert Quick Start
Xtium2-CXP PX8 User's Manual
Flat Field Correction Dialog
The Flat Field Correction dialog provides a three-step process to acquire two reference images and
then save the flat field correction data for the camera used. To aid in determining if the reference
images are valid, a histogram tool is provided so that the user can review the images used for the
correction data.
Figure 14: CamExpert Flat Field Correction Dialog
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Setup the camera to capture a uniform black image. Black paper with no illumination and
the camera lens’ iris closed to minimum can provide such a black image.
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Click on Acquire Dark Image. The flat field demo will grab a video frame, analyze the
pixel gray level spread, and present the statistics. The desired black reference image should
have pixel values less than 20. If acceptable, accept the image as the black reference.
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Setup the camera to acquire a uniform white image (but not saturated white). Even
illumination on white paper can be used, with a minimum gray level of 128. It is preferable
to prepare for the white level calibration before the calibration procedure.
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Click on Acquire Bright Image. The flat field demo will grab a video frame, analyze the
pixel gray level spread, and present the statistics. The captured gray level for all pixels
should be greater than 128. If acceptable, accept the image as the white reference.
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Click on Save. The flat field correction data is saved as a TIF image with a file name of your
choice (such as camera name and serial number).
Using Flat Field Correction
On the CamExpert menu bar, enable Flat Field correction (Pre-Processing >
Flat Field Correction > Hardware or Software). Now when doing a live grab or snap, the
incoming image is corrected by the current flat field calibration data for each pixel.
Use the command Pre-Processing > Flat Field Correction > Load to load in a flat field
correction image from previous saved calibration data. CamExpert allows saving and loading
calibration data for all cameras used with the imaging system.
