Shading Correction; Shading Correction Guidelines; Using The Cct+ To Work With Shading Correction - Basler L100k User Manual

3.6 Shading Correction

In theory, when the camera captures an image of a uniform object, the values output from the
pixels in the camera should be uniform. In practice, however, variations in optics and lighting can
cause the camera output to be non-uniform even when the camera is viewing a uniform object.
The L100 camera is equipped with a shading correction feature that allows the camera to correct
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the captured image for variations caused by optics and lighting.
The camera corrects for shading variations by applying a "shading correction table" to each
captured image. Before you enable the shading correction feature, you must create a shading
correction table and upload it to the camera. You can use either the Camera Configuration Tool
Plus (CCT+) or binary commands to create and upload the table and to enable the shading
correction feature. See Section 3.6.2 for instructions on using the CCT+ to perform these functions
and Section 3.6.3 for instructions on performing them with binary commands.
Please note that when using Shading Correction, you must follow the guidelines listed in Section
3.6.1.

3.6.1 Shading Correction Guidelines

When using shading correction, make sure that you take the following guidelines into account:
• Shading correction is only available in 8-bit output mode. Activating 10-bit output mode will
disable shading correction.
• Any time that you make a change to optics or lighting, you must create a new shading correc-
tion table. You must also create a new shading table any time that you change the gain set-
tings on the camera or the digital shift.
Using an out of date shading correction table can result in poor quality images.
• During the process of creating a shading table, you will capture lines while the camera is
focused on a uniform gray target. The ratio of the value for the lightest pixel in the captured
lines to the value for the darkest pixel in the captured lines must not be more than 2/1. If it is
greater than 2/1, the shading correction feature will not be able to fully correct the shading
variations.

3.6.2 Using the CCT+ to Work With Shading Correction

To create and upload a shading correction table and to enable shading correction using the CCT+:
1. Open the CCT+. Use the Shading Correction setting in the Output parameter group to set
shading correction to off (Shading Correction must be off when you capture data for the
shading table).
2. Use the Video Data Output Mode setting to set your camera for Single 8 bit or Dual 8 bit
output mode. (Before selecting Dual 8 bit mode, make sure that your frame grabber is
capable of supporting dual output.)
3. Place a uniform gray target in the camera's field of view.
4. Make sure that your optics and lighting are set to their normal operating conditions. Optics
and lighting must be set before you capture any data.
5. Make sure that your grabber is properly configured to accept the output mode that you
selected in step 2.
6. Use the software included with your frame grabber to capture and store at least 100 lines of
data to a file. Save the resulting file as an image in GIF, JPG, JPEG, or PNG format. (The
BASLER L100
k Series
DRAFT
Operation and Features
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